MITIGATING SHORT-­‐TERM PV OUTPUT INTERMITTENCY Prepared by Richard Perez and Sergey Kivalov ASRC, University at Albany Thomas E. Hoff, John Dise and David Chalmers Clean Power Research 12/16/2013 GW University Solar Institute Contracts No. 1000178044 & 1000177911 This overview report describes the objectives, the approach, and the key results produced by the University at Albany and Clean Power Research on estimating the cost of mitigating the short-­‐term intermittency of solar power generation fed onto US power grids. Two appendices containing details on methodology and a complete set of results are appended. BACKGROUND AND OBJECTIVES The intermittency of the solar resource is an issue that cannot be ignored when planning
for high penetration of PV on power grids. A considerable amount of research has been
devoted to this subject over the last five years [1-16] and has led to a better understanding
of short-term solar resource variability and how it is influenced by the considered
temporal and spatial scales.
However understood, intermittency must be addressed and appropriately dealt with. In
this perspective, we approach the issue of short-term PV output intermittency from a
management standpoint by determining the cost of actively mitigating it using “shockabsorbers” consisting of short-term energy storage buffers.
Figure 1 shows an example of high-frequency (one-minute) fluctuations for a single solar
system on partly cloudy day. The figure also illustrates how this short-term variability
can be almost eliminated by operating an energy buffer taking in short-term output spikes
and releasing energy during short-term output deficits. The central question of this report
is: what is the cost of this buffer?
800
600
800
PV output
600
buffered PV
400
Buffer transit
500
200
400
0
300
-­‐200
-­‐400
200
100
0
-­‐600
Maximum 1 minute ramp rate: 400 W/kW
Maximum 1 minute ramp rate: 10 W/kW
-­‐800
ENERGY BUFFER IN/OUT TRANSIT (Watts per kW)
PV SYSTEM OUTPUT (Watts per kW)
700
1000
clear sky PV
-­‐1000
Figure 1: Illustrating how short-terms ramps on a partly cloudy day can be almost eliminated by
operating a storage buffer whose output is set to equal the trailing running mean average of the
PV system.
Quantifying intermittency: Solar Resource variability can be quantified using several
metrics. The authors and others have proposed the standard deviation of the changes in
clear sky index [16] as a suitable metric to both quantify and model variability. However
utilities and grid operators are concerned with a more tangible metric: the power output
ramp rate quantifying the change (the ramp) in power output from one time interval to
the next. Ramps have been observed to be in excess of 100% of installed capacity for
short-term spikes [17]. Utilities are considering applying maximum ramp rate acceptance
windows to solar power fed onto their grids. For instance the Puerto Rico’s Electric
Power Authority imposes a limit of 10% of installed capacity for one-minute ramps.
Cost of mitigation: Intermittency mitigation is quantified here by the cost of the energy
buffer that is needed to achieve a given ramp rate reduction objective. This cost depends
on the specs of the storage buffer – namely its power and its energy reserve capacity -and upon its technology. In the present context, considering ramps of one minute to two
hours, these technologies would likely consists of lead-acid batteries for the upper end of
the time scale range and super-capacitors or fly-wheels for the lower end. A simple
“technology-agnostic” model was developed to estimate the per kW and per kWh storage
capacity costs as a function of kW and kWh requirements. This model, derived from the
specs of currently available storage technologies, is illustrated in Figure 2.
2 Figure 2: Buffer storage cost model used for the present investigation. The thick semi-transparent
curve represents the model per se. It is applied here in the region corresponding to lead acid
batteries fly-wheels and super-capacitors -- source [18].
The cost of PV output intermittency mitigation is determined as a function of several
parameters that specify the mitigation requirements of the grid operators, the time scale
of concern, the PV resource location and footprint, and the possibility to accurately
forecast PV power output:
Ramp rate reduction objective: the cost of intermittency mitigation depends upon
the desired level of mitigation. Here we consider objectives for maximum
allowable ramp rate ranging from 25% down to 1% of installed PV capacity.
Time scale: Ramps must be placed in an appropriate temporal context to both
understand their impact and implement appropriate solutions. Figure 3 contrasts
one-minute and hourly ramp rates occurring on a given day at a particular
location. At different time scales ramp rates have different causes, have different
magnitudes, and engender different concerns which have different solutions. For
instance one minute ramp rates are caused by individual clouds and cloud edge
effects. These short-term ramp may impact local voltage regulation. Hourly ramp
rates are caused by the evolution of entire cloud fields and are relevant to
contingency power generation dispatching.
We use a systematic approach to understand and quantify the impact of time scale
on intermittency mitigation by analyzing ramp rate time scales ranging from one
minute to two hours.
Spatial Scale: The well-documented spatial smoothing of solar resource
fluctuations affects ramp rates differently as a function of time scale [2]. Shortterm fluctuations are quickly smoothed out as the solar generation footprint
increases to a few square km, while longer term fluctuations take more spatial
distribution to be mitigated.
3 We also approach this question systematically by analyzing solar generation
footprints ranging from one centralized location up to a resource distributed over
a 200x200 km region representative of a utility service area.
One Minute
Max ramp = 400 W/kW
One Hour
Max ramp = 180 W/kW
Figure 3: Comparing one-minute and hourly ramps for the
same day/location
Availability of solar resource forecasts: We explore whether knowing the future
output of solar generators can be used to more effectively manage the shock
absorbing energy buffers, hence reduce their required size and cost. Figure 4
illustrates how the buffering effect shown in Figure 1 can be optimized if perfect
forecasts can be used to anticipate the intermittency mitigation performance of the
buffer.
In this report we contrast the mitigation costs achieved by operating the buffers
without forecasts to the mitigation costs achieved when perfect forecasts are
available.
Influence of location: Through three case studies in Hawaii, California and the
southeastern US which have very distinct climatic environments (respectively
sub-tropical, arid and continental) we investigate the influence of the local solar
climate upon the specs of short-term energy buffers, hence their cost.
4 REQUIRED BUFFER: 180 Wh / KW
NO FORECAST AVAILABLE
REQUIRED BUFFER: 70 Wh / KW
PERFECT FORECAST AVAILABLE
Figure 4: Intermittency buffering using historical-only PV production (top)
and historical + ideally forecast PV production (bottom). because short and
medium term spikes can be anticipated in the latter case, the size of the
buffer needed to accomplish a given ramp reduction objective can be
minimized.
METHODOLOGY Our approach is empirical and based on the analysis of a large sample of data at the three selected locations illustrated in Figure 5. 5 For each site we analyze PV output simulated from a single point up to a 200x200km area surrounding this point. For the single point PV is simulated from one-­‐minute irradiance measurements. For the surrounding areas, PV is simulated from one minute high-­‐resolution (1 km) satellite-­‐derived irradiances from SolarAnywhere [19]. As explained in Appendix 1, the satellite-­‐derived irradiances are post-­‐calibrated to enhance their dynamic range so as to match measured ramp observations. The selected geometry for PV system is horizontal mount – i.e., not ideal from an energy output standpoint, but fully representative to capture the power output transients of interest to the current study. Goodwin Creek
Mississippi Hanford California
Kalaeola
Hawaii
Location Hanford, CA
Goodwin Creek, MS
Kalaeola, HI
latitude 36.31° N
34.25° N
21.32° N
Longitude Elevation Prevailing Climate
119.63° W
73 m
Semi-­‐arid
89.87° W
98 m
Warm continental
159.09° W
20 m
Subtropical
Data Source
NOAA-­‐ISIS
NOAA-­‐ SURFRAD
NREL
Figure 5: Selected experimental locations
A total of 2,808 PV output simulations involving over 32 billion data points are performed for each possible temporal/spatial/mitigation/site/forecast combination -­‐-­‐ see Table 1. RESULTS OVERVIEW A comprehensive sample of the 2,808 simulations is presented and discussed in Appendix 1, and a complete set of results is presented in Appendix 2. Here we provide a high-­‐level view focusing on two key aspects of the study: 6 (1) Showing how variability at each location evolves as a function of time scale and footprint. (2) Extracting the cost of intermittency mitigation for a plausible operational scenarios. TABLE 1: Simulation case study overview Mitigation objective (Maximum acceptable ramp rate % of PV Capacity)
0.5%
1.0%
2.5%
5.0%
10.0%
15.0%
25.0%
Tim resolution Spatial resolution (minutes)
km
1
5
15
30
60
120
single point
1x1
2x2
3x3
5x5
8x8
13x13
30x30
50x50
80x80
130x130
200x200
Locations
Forecast California
South Central US
Hawaii
No Forecasts
Ideal Forecasts
Variability as a function of footprint and time scale: We examine both variability metrics mentioned above -­‐-­‐ the reference metric equal to standard deviation of the clear sky index changes, and the more pragmatic measure consisting of the highest observed ramp. Figure 6 illustrates the trends observed at each location for the first metric as a function of time scale and footprint. Consistent with earlier findings by the authors and others [e.g., 2] variability decreases as a function of footprint at a rate that is dependent upon the considered time scale – the decrease is more pronounced for the shorter time scales. Some differences between locations are noteworthy: Variability increases as a function of time scale at all locations with an exception for
Hawaii, where the trend is reversed for small footprints. This is likely because of the
frequent occurrence of puffy cloud conditions at that location resulting in high frequency
variability at that site. As footprint increases beyond ~ 10 km, the trends are comparable
at all locations, with highest overall values found for Goodwin Creek and lowest values
found for Central California -- a likely results of the higher occurrences of intermediate
conditions in the Southeastern US compared to California, combined with faster moving
cloud systems in the continental US inducing a smaller decrease of variability with
distance [16]. 7 Figure 7 illustrates highest observed ramps as a function of time scale and footprint. The
trends are not as smooth and well defined as in Fig. 6 because this metric represents the
highest ramp observation in each case – i.e., a one-time extreme event. Nevertheless
strong tendencies do emerge: for small footprints, highest ramps are observed for high
frequency ramps, while this tendency is reversed -- highest values for low frequency
ramps -- beyond 1-5 km footprint. This is because high frequency ramps are quickly
smoothed out as footprint increase.
Hanford
Goodwin Creek
Kalaeola
Figure 6: Variability (Watts per PV kW) as a function of footprint and time scale
The similarity observed between all sites is remarkable for this metric, particularly for
small footprints where ramp values are almost identical for all sites at all time scales
Cost of ramp mitigation in an operational context: Operationally, grid operators will target different variability mitigation objectives as a function of time scale as well as PV generation footprint, depending on their ability to react via ancillary services for high frequency events and with contingency power generation for longer ramps. Ramp reduction targets are likely to be more stringent for the lowest time scales and more lenient as time scales increase and grid operators have time to plan and react. 8 Hanford
Goodwin Creek
Kalaeola
Figure 7: Highest observed ramp (Watts per PV kW) as a function of footprint and time scale
As an example of plausible operational scenario, results in Figure 8 illustrate operational ramp mitigation costs for the following maximum acceptable ramp targets: •
5% of installed PV capacity at one-­‐minute, •
10% at 5 minutes, •
15% at 15 minutes, •
25% at one hour. Costs are shown for five PV Generation footprints: •
Point-­‐specific, •
5x5 km, •
20x20km, •
50x50 km, •
200x200 km. For a single point, the operational mitigation cost to meet all requirements at all time scales ranges from $500 per installed PV kW in California to $900 in South-­‐
9 Central US. However this cost is reduced considerably and becomes comparable for all locations (~$400 per PV kW) if perfect forecasts are available to provide intelligence to the shock absorbing buffers. Hanford
NO FORECAST
PERFECT FORECAST
Kalaeola
Goodwin Creek
Figure 8: Operational scenario intermittency mitigation buffer cost
Mitigation costs decrease substantially with foot-­‐print. For instance a 50x50 km area corresponding to a small utility drives mitigation cost down to ~$ 100-­‐200 with forecasts, i.e., representing 5%-­‐15% of a PV installation’s cost. It is important to note that the cost figures presented here are dependent upon the technology model shown in figure 2 which is based upon current storage technology costs. It is likely that these costs will be driven down commensurately with, and possibly more, than PV costs. Another cost of operating buffers that should not be ignored is the loss that is incurred by circulating some of the energy produced in and out of the buffers. Figure 9 shows the fraction of PV energy that would lost for all cases analyzed assuming a mean 90% round-­‐trip efficiency. In all case this loss is negligible (0.5% in the worse case scenario: single point system in Hawaii with no forecasts available.) CONCLUSIONS AND RECOMMENDATIONS 10 The present analysis shows that ramp rate mitigation across multiple temporal scales from minutes can be mitigated with energy buffers at cost amounting to a small fraction of a PV installation cost. In addition, the study showed that: • Buffer energy losses are minimal in all case figures analyzed (<< 1%). • Accurate forecasts can reduce buffer capital cost by 40-­‐50%. • Reducing dispersed generation’s variability instead of focusing on single installations would be considerably more cost effective when conditions permit. • Bottom line differences between very different climatic environments are not considerable. An important continuation to this work will be to investigate to which extent non-­‐
ideal state of the art forecast could reduce buffer costs compared to ideal forecasts. Hanford
NO FORECAST
PERFECT FORECAST
Kalaeola
Goodwin Creek
Figure 9: Operational scenario intermittency mitigation buffer roundtrip energy losses
11 REFERENCES [1] Hinkelman L., R. George and M. Sengupta, 2011: Differences between Along-Wind
and Cross-Wind Solar Variability. Proc. Solar 2011, American Solar Energy Society
Conf., Raleigh, NC
[2] Hoff T., & R. Perez (2012): Modeling PV Fleet Output Variability, Solar Energy 86,
8, 2177-2189
[3] Hoff, T. E., Perez, R. 2010. “Quantifying PV power Output Variability.” Solar
Energy 84 (2010) 1782–1793
[4] Jamaly, S., Bosch, J., Kleissl, J. 2012. “Aggregate Ramp Rates of Distributed
Photovoltaic Systems in San Diego County.” IEEE Transactions on Sustainable Energy,
in press
[5] Lave, M., J. Kleissl, Arias-Castro, E., High-frequency fluctuations in clear-sky index,
Solar Energy, doi:10.1016/j.solener.2011.06.031, 2011
[6] Lorenz E., T. Scheidsteger, J. Hurka, D. Heinemann and C. Kurz, (2011): Regional
PV power prediction for improved grid integration. Progress in Photovoltaics, 19, 7, 757771.
[7] Mills, A., Wiser, R. 2010. Implications of Wide-Area Geographic Diversity for ShortTerm Variability of Solar Power. Lawrence Berkeley National Laboratory Technical
Report LBNL-3884E.
[8] Murata, A., H. Yamaguchi, and K. Otani (2009): A Method of Estimating the Output
Fluctuation of Many Photovoltaic Power Generation Systems Dispersed in a Wide Area,
Electrical Engineering in Japan, Volume 166, No. 4, pp. 9-19
[9] Perez M., and V. Fthenakis, (2012): Quantifying Long Time Scale Solar Resource
Variability. Proc. WREF, Denver, CO.
[10] Perez, R., T. Hoff and S. Kivalov, (2011a): Spatial & temporal characteristics of
solar radiation variability. Proc. of International Solar Energy (ISES) World Congress,
Kassel, Germany
[11] Perez, R., Kivalov, S., Schlemmer, J., Hemker Jr., C. , Hoff, T. E. (2011b):
Parameterization of site-specific short-term irradiance variability, Solar Energy 85 (2011)
1343-1353
[12] Perez, R., Kivalov, S., Schlemmer, J., Hemker Jr., C. , Hoff, T. E. (2012): “Shortterm irradiance variability correlation as a function of distance.” Solar Energy 86, 8, pp.
2170-2176
[13] Wiemken E., H. G. Beyer, W. Heydenreich and K. Kiefer (2001): Power
Characteristics of PV ensembles: Experience from the combined power productivity of
100 grid-connected systems distributed over Germany. Solar Energy 70, 513-519
[14] Woyte, A., Belmans, R., Nijs, J. (2007): Fluctuations in instantaneous clearness
index. Solar Energy 81 (2), 195-206.
[15] Marcos J., L. Morroyo, E. Lorenzo and M. Garcia, (2012): Smoothing of PV power
fluctuations by geographical dispersion. Prog. Photovolt: Res. Appl. 2012; 20:226–237
[16] Perez, R., T. Hoff, (2013): Solar Resource Variability, in: Solar Resource
Assessment & Forecasting (Ed. J. Kleissl), Elsevier, 2013
12 [17] Yordanov, G., O. Mitdgard, O. and L. Norum (2013): Overirradiance (Cloud
Enhancement) Events at High Latitudes. IEEE Journal of Photovoltaics, 3, 1, 271-278.
[18] Germa, J.M., & M. Perez, (2012): Energy Storage: Technology, Applications &
trends. Cluster Maritime Français. 10/3/12
[19]
SolarAnywhere
(2013):
http://www.cleanpower.com/products/solaranywhere/solaranywhere-data /
13 APPENDIX 1 MITIGATING SHORT-TERM PV OUTPUT
INTERMITTENCY
Richard Perez
Sergey Kivalov
University at Albany
Albany, New York, USA
Thomas E. Hoff
John Dise
David Chalmers
Clean Power Research
Napa, California, USA
Our objective is to estimate the cost of mitigating the short-term variability of solar
power generation fed onto US power grids. We approach the issue of short-term PV
output intermittency from a management standpoint by determining the cost of actively
mitigating it using “shock-absorbing” short-term energy buffers. Using three case studies
in California, Hawaii and the southern US as experimental support, we determine this
cost as a function of (1) the desired amount of variability mitigation; (2) the considered
variability time scale, (3) the PV resource’s geographical footprint, and (4) the
availability of accurate solar forecasts. We show that, in a plausible operational context,
the cost of mitigating variability across time scales ranging from one minute to a couple
of hours could be kept below 20-35 cents per installed PV kW.
BACKGROUND Short-term PV output variability has been thoroughly studied in recent years as it became
a concern associated with the increase of PV penetration on power grids [1-16]. It is now
14 better understood, and in particular the smoothing effect occurring with dispersed
generation is well documented.
15 However understood, variability remains a concern to grid operators and utilities, who are
at the receiving end of the variable resource, and who have to manage it appropriately.
Therefore we frame the present inquiry from a grid operator’s standpoint by determining
the cost of keeping the variable resource’s ramp rates below specified thresholds. This
cost is quantified by the shock-absorbing hardware —an energy buffer—that receives the
variable PV output and filters it to deliver an output with specific maximum ramp rate
requirements. This cost is determined as a function of:
(a) The considered ramp rate time scale—from one minute to two hours;
(b) The footprint of the generating resource—from a single point to a PV resource
distributed over 200x200 km; i.e., going from a resource with full site-specific
variability including cloud’s edge intensification effects [e.g., 17], to a
resource where variability is already smoothed by geographic distribution;
(c) The solar climatic environment – including semi-arid, tropical and temperate
locations; and,
(d) The availability or not of solar forecasts.
APPROACH Mitigating Variability The metrics used to quantify variability mitigation are the specs and the cost of the
energy buffer needed to keep all ramp rates below a selected level. As PV output
fluctuates, excess variability is filtered by the buffer that absorbs or releases energy
appropriately so that the ramp rate of the PV+buffer ensemble seen by the grid does not
exceed the selected ramp rate at any time. The buffer is driven by an algorithm that sets
its output to equal the running mean of the unfiltered PV input. The running mean time
window depends upon the desired degree of ramp rate reduction. Fig. 1 illustrates this
buffering effect on a partly cloudy day. In this example, the maximum one-minute ramp
rate seen by the grid (buffered PV) is less than 10 W per installed kW.
Figure 1: Illustrating the buffering of PV output.
16 Forecast availability: Operationally the running mean algorithm can be a trailing running
mean since this information could be readily available to the buffer. The running mean
could also be centered on the current time if perfect forecasts are available (i.e. if future
output is known).
Predictable vs. unpredictable ramp rate: Ramp rates resulting from solar geometry are
fully predictable and could therefore be accounted and planned for by grid operators (e.g.,
see the clear sky profile in Fig. 1). Therefore, we focus here on unpredictable ramp rates
defined as the difference between the observed ramp rates and the ramp rates that would
result from solar geometry alone (i.e., conserving the same clear sky index from one time
interval to the next). For very short-term fluctuations (less than 10 minutes), the
difference between the two is negligible. However, for longer time scales (one to two
hours), the difference can be significant.
Buffer specs and cost: The specs of the buffer —power and energy capacity — are
determined experimentally by analyzing PV output time series over a one-year period.
This analysis yields the maximum transfer of power in and out of the buffer, and the
maximum cumulative energy to be stored in the buffer, so as to accommodate the
selected ramp rate-specific output at all times. Depending on the buffer’s power and
energy requirements, different technologies may be considered. Very small energy and
high power requirements would be met by fly wheels or capacitors. As energy vs. power
requirements augment, technologies would evolve toward supercapacitors and batteries.
For this study, we built a simple “technology-agnostic” cost model based on current
reported costs for state-of-the-art energy storage equipment. This cost model is illustrated
in Fig. 2
Figure 2: Buffer storage cost model [18]
17 Data Analysis The experimental data used to determine buffer specs consist of one-year PV output time
series for horizontally-mounted PV systems operating in three climatically distinct
locations: Hanford, in Central California, Goodwin Creek in the southeastern US, and
Kalaeloa in Hawaii. For each location, a total of 78 PV output time series are analyzed
encompassing 13 geographical footprints—from a single point, to 200x200 km integrated
output—and 6 time scales —from one minute to two hours.
One-minute PV output time series are simulated from one-minute high-resolution
SolarAnywhere irradiances [19] in each 1x1 km high-resolution point in the considered
200x200 km regions (i.e., a total of ~ 40,000 points per region). These time series are
averaged appropriately in space and in time to produce the desired time scales and
footprints. The single-point PV output located at the center of each 200x200km region is
simulated from actual irradiance measurements [20].
For any selected ramp rate reduction target and for each of the 78 space/time
configurations, the buffer’s energy and power requirements as well as the running mean
window are determined by calculating the difference between the running mean PV and
the unfiltered PV output. The power requirements correspond to the highest absolute
difference between the two, while the energy requirements correspond to the largest sum
of accumulated differences while accounting for storage efficiency set at 95%. For each
simulation, two types of running mean windows are considered: (1) trailing—no forecasts
available, and (2) centered—ideal forecasts available.
Trailing windows are extended as necessary to meet the maximum allowable ramp rate
objectives. The lowest ramp rate objectives considered for this analysis are a function of
the considered time scale, and range from 0.5% of installed capacity for one-minute
fluctuations, to 10% for two-hour fluctuations.
Post-­‐calibration of satellite data Because satellite-based simulations are derived from irradiance models that are bound at
the high end by clear sky, and at the low end by standard overcast conditions, they tend,
at this stage of their development, to underestimate the dynamic range generated by
highly variable conditions (e.g., see [10]). Short of producing a new satellite model with
enhanced dynamics, we apply here post-calibration approach that ensures that simulation
output discontinuities observed as a function of footprint from the single (measured)
point to the extended (satellite) points are eliminated. This process is illustrated in Fig. 3
for one of the calculated variables: 15 minute PV output variability. The [underestimated]
satellite-derived trend is adjusted upward so that it naturally converges to the (measured)
single point without discontinuity. A similar post-result calibration is applied to all the
simulated output variables including, in addition to variability, all the buffer specs—
energy, power and cost —produced in the present analysis.
18 Figure 3: Illustration of the satellite data post-result calibration process. This example is
shown for the 15-minute PV output variability observed in Hanford.
RESULTS PV output variability Figs. 4 and 5 report respectively the PV output variability and maximum absolute ramps
observed at each location as a function of time scale and geographic footprint. PV output
variability is defined as the standard deviation of the ramps per Hoff and Perez, [16].
While these results are consistent with earlier findings by the authors and others [16]
showing that variability decreases as a function of footprint at a rate that is dependent
upon the considered time scale, they also show interesting site differences and similarities
between locations:
Variability increases as a function of time scale at all locations in the considered 1-minute
to 2-hour domain, with an exception for Hawaii, where the trend is reversed for very
small footprints. This is likely because of the frequent occurrence of puffy cloud
conditions resulting in high frequency variability at that site. As footprint increases
beyond ~ 10 km, the trends are very similar for all sites, with highest overall values found
for Goodwin Creek and lowest values found for Central California -- a likely results of
the higher occurrences of intermediate conditions in the Southeastern US compared to
California combined to faster moving cloud systems inducing a smaller decrease of
variability with distance [2, 12, 16].
19 Figure 4: PV Output Variability (standard deviation of ramps) a Function of time scale
and footprint
When looking at maximum ramps as the metric for variability, the similarity observed
between all sites is remarkable (see Fig. 5), particularly for small footprints where ramp
values are almost identical for all sites at all time scales. For small footprints, highest
values are observed for high frequency ramps, while this tendency is reversed -- highest
values for low frequency ramps -- beyond 1-5 km footprint.
20 Figure 5: Maximum absolute ramp rate observed at each location as a function of time
scale and footprint.
Mitigating variability – buffer specs Buffer specifications were determined for each of the 78 space/time configuration at each
location. For each simulation, up to seven ramp mitigation targets and two forecast
21 scenarios were considered. We present here a crosscut of these results that is
representative of this work’s key findings, including:
(a) Influence of time scale, foot print and forecast availability for a given ramp rate
mitigation objective;
(b) Influence of ramp rate mitigation objective for selected footprints and time
scales; and
(c) Determination of buffer specs for a plausible operational objective.
Complete simulation results will be made available in a project report scheduled for
publication at the end of 2013 [21].
Influence of time scale, foot print and forecast availability for a given ramp mitigation objective: The ramp objective selected to illustrate the results is
100Watts per kW PV (i.e., 10% of installed capacity). For all considered time scales,
footprints, locations and forecast scenarios, we present the buffer specification required
to meet this maximum output ramp rate objective. Results are presented in Figs. 6, 7 and
8 for Hanford, Goodwin Creek and Kalaeloa, respectively.
Buffer Energy requirements are primarily influenced by the considered time scale.
Energy requirements are insignificant for short time scales and gradually increase with
the considered time scale. The impact of footprint is also noticeable but not as
pronounced, particularly for the longer time scales. The influence of forecast availability
is noteworthy: energy requirements are markedly smaller when forecasts are available to
drive the buffer’s running mean algorithm. This is particularly visible for the longer time
frames, where the non-forecast trailing window must reach into the previous day’s
conditions to meet the 100 W/kW maximum ramp rate objective presented in this
example. Interestingly, the forecast advantage for longer time frames is more pronounced
in California than it is in Hawaii. A likely explanation is that cloud conditions in Hawaii
do not evolve as they do in California or Goodwin Creek, driven by the passing of fronts
and cloud structures, but tend to remain comparable and repetitive over time, (i.e., the
future is not as different from the past in Hawaii as it may be in California or the
continental US.)
22 Figure 6: Buffer energy (top), capacity (middle) and cost per PV kW as a function or
ramp rate time scale, footprint and availability of forecast in Hanford, California. These
specs correspond to a maximum acceptable ramp rate of 100W per PV kW at all
time/spatial scales.
23 Figure 7: Same as Fig. 6, but for Goodwin Creek, Mississippi.
24 Figure 8: Same as Figs. 6 and 7, but for Kalaeloa, Hawaii.
Buffer power requirements peak for short time scales and small footprints. As footprint
increases, power requirements for short time scales decrease rapidly, while longer time
scales decrease more slowly. Differences between sites are minor and so is advantage of
forecasts which do not substantially reduce the required buffer power rating.
Buffer cost is a function of both energy and capacity requirements. In this 10% rated
capacity maximum ramp objective example, one minute ramp mitigation with perfect
forecast availability would cost $300-$400 for all locations per PV kW for single point
and decrease to zero within a few km. Hourly ramps could be mitigated at a cost of $400500 per PV kW for a single point system, gradually declining to $100-$150 for 200x200
km footprints representative of utility service areas. Mitigation costs are lowest for
California, followed closely by Hawaii. Highest mitigation are found in the SE US – a
likely combination of the frequent occurrence of partly cloudy conditions associated with
fast moving fronts and cloud structures – this is consistent with the observation
decorrelation distance between pairs of points increases with prevailing cloud speed (e.g.
see [16]).
Buffer cost would typically be $100-$250 higher in the absence of forecasts.
Influence of ramp rate mitigation objective for selected footprints and time scales: In Fig. 9 we illustrate the impact of the ramp mitigation objective on
25 buffer cost for two time scales (1-minute and 15-minute) and two footprints (1x1 and
3x30 km). This sample shows that mitigation cost decreases significantly with the
mitigation target—and can reach zero when the target is already met by the geographical
smoothing effect – this is the case for Kalaeloa’s 30x30 km footprint where 15 minute
ramp rates are below the desired 25% PV rated capacity at all times without any need for
buffering. The results in Fig. 9 also show that forecast availability systematically leads to
lower costs—an average of $50-300/PV kW across this illustrative sample.
Operational ramp rate mitigation scenario: Operationally, grid operators will
likely target different variability mitigation objectives as a function of time scale as well
as PV generation footprint, depending on their ability to react via ancillary services
and/or variable power generation. These targets are likely to be more stringent for the
lowest time scales and more lenient as time scales increase and grid operators have time
to plan and react.
As an example of plausible operational scenario, results in Table I, II and III (respectively
Hanford, Goodwin Creek and Kalaeloa) illustrate operational mitigation costs for the
following ramp mitigation targets: 5% of installed PV capacity at one-minute, 10% at 5
minutes, 15% at 15 minutes and 25% at one hour. Costs are shown for five dispersion
footprints: point-specific, 5x5, 20x20, 50x50 and 200x200 km. Also shown is the fraction
of PV energy lost via round trip through the mitigation buffer.
For a single point, this operational cost is of the order of $300-350 per PV kW with
perfect forecasts and would be about 40% higher without. Dispersed at the level of a
large substation covering 20x20 km, PV generation could be operationally mitigated for
$150-250 / kW, but this cost would be nearly twice as much without forecasts.
26 Figure 9: Influence of ramp mitigation objective for selected footprints and time scales
27 W ITHOUT FORECASTS W ITH FORECASTS Table I: Operational scenario buffer cost – Hanford, California
Max acceptable ramp (Watts/kW installed)
One minute
50
5 minutes
100
15 minutes
150
one hour 250
Max acceptable Ramp Rate ramp time scale
(Watts/kW installed)
One minute
50
5 minutes
100
15 minutes
150
one hour 250
Ramp Rate time scale
single point
Buffer cost
Losses $ 357
0.08%
$ 370
0.10%
$ 341
0.12%
$ 251
0.09%
single point
Buffer cost
Losses $ 458
0.13%
$ 506
0.15%
$ 492
0.18%
$ 360
0.18%
Footprint Dimension (km)
5x5
20x20
50x50
Buffer Buffer Buffer cost
cost
cost
Losses Losses Losses $ 103
0.01% $ 43
0.00%
-­‐-­‐
0.00%
$ 248
0.04% $ 123
0.02% $ 21
0.00%
$ 277
0.05% $ 160
0.03% $ 63
0.01%
$ 195
0.06% $ 146
0.05% $ 127
0.04%
Footprint Dimension (km)
5x5
20x20
50x50
Buffer Buffer Buffer cost
cost
cost
Losses Losses Losses $ 197
0.04% $ 83
0.01%
-­‐-­‐
0.00%
$ 406
0.07% $ 326
0.05% $ 102
0.01%
$ 466
0.08% $ 410
0.07% $ 205
0.03%
$ 428
0.09% $ 397
0.09% $ 352
0.08%
200x200
Buffer cost
Losses -­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
200x200
Buffer cost
Losses -­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
W ITHOUT FORECASTS W ITH FORECASTS Table II: Operational scenario buffer cost – Goodwin Creek, Mississippi
Max acceptable ramp (Watts/kW installed)
One minute
50
5 minutes
100
15 minutes
150
one hour 250
Max acceptable Ramp Rate ramp time scale
(Watts/kW installed)
One minute
50
5 minutes
100
15 minutes
150
one hour 250
Ramp Rate time scale
single point
Buffer cost
Losses $ 406
0.18%
$ 405
0.19%
$ 405
0.19%
$ 457
0.24%
single point
Buffer cost
Losses $ 579
0.25%
$ 602
0.27%
$ 654
0.29%
$ 919
0.40%
Footprint Dimension (km)
5x5
20x20
50x50
200x200
Buffer Buffer Buffer Buffer cost
cost
cost
cost
Losses Losses Losses Losses $ 109
0.03%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
$ 235
0.08% $ 122
0.04% $ 46
0.01%
-­‐-­‐
0.00%
$ 351
0.11% $ 175
0.06% $ 153
0.04% $ 72
0.01%
$ 362
0.11% $ 337
0.10% $ 251
0.08%
-­‐-­‐
0.00%
Footprint Dimension (km)
5x5
20x20
50x50
200x200
Buffer Buffer Buffer Buffer cost
cost
cost
cost
Losses Losses Losses Losses $ 280
0.08% $ 74
0.02%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
$ 434
0.14% $ 305
0.09% $ 180
0.05% $ 94
0.01%
$ 583
0.20% $ 442
0.13% $ 355
0.11% $ 171
0.00%
$ 641
0.18% $ 630
0.17% $ 567
0.16%
-­‐-­‐
0.00%
28 W ITHOUT FORECASTS W ITH FORECASTS Table III: Operational scenario buffer cost – Kalaeloa, Hawaii
Max acceptable ramp (Watts/kW installed)
One minute
50
5 minutes
100
15 minutes
150
one hour 250
Max acceptable Ramp Rate ramp time scale
(Watts/kW installed)
One minute
50
5 minutes
100
15 minutes
150
one hour 250
Ramp Rate time scale
single point
Buffer cost
Losses $ 421
0.42%
$ 380
0.38%
$ 359
0.34%
$ 355
0.30%
single point
Buffer cost
Losses $ 557
0.51%
$ 549
0.44%
$ 512
0.38%
$ 618
0.29%
Footprint Dimension (km)
5x5
20x20
50x50
Buffer Buffer Buffer cost
cost
cost
Losses Losses Losses $ 182
0.06%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
$ 223
0.12% $ 56
0.03%
-­‐-­‐
0.01%
$ 214
0.12% $ 144
0.06% $ 43
0.02%
$ 229
0.11% $ 163
0.08% $ 120
0.05%
Footprint Dimension (km)
5x5
20x20
50x50
Buffer Buffer Buffer cost
cost
cost
Losses Losses Losses $ 277
0.14% $ 32
0.01% $ 31
0.01%
$ 382
0.18% $ 160
0.07% $ 79
0.02%
$ 381
0.18% $ 292
0.11% $ 143
0.04%
$ 411
0.15% $ 378
0.12% $ 303
0.09%
200x200
Buffer cost
Losses -­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.00%
200x200
Buffer cost
Losses -­‐-­‐
0.00%
-­‐-­‐
0.00%
-­‐-­‐
0.04%
-­‐-­‐
0.00%
CONCLUSIONS We asked the question: what is the cost of mitigating PV output intermittency to any
desired level using short-term energy “shock absorbing” buffers? Through three case
studies in California, the Southeastern US and Hawaii, we quantified this cost as a
function of the maximum allowable ramp rate, the intermittency time scale, and the
geographic dispersion of the PV resource. We showed that this cost was appreciably
dependent upon the availability of solar forecasts that could be used to control the
operation of the intermittency absorbing buffers.
A plausible operational scenario setting acceptable ramp rate levels as a function of their
time scale and PV footprint showed that:
•
•
•
•
•
•
•
Intermittency can be mitigated at a cost amounting to less than 10%-­‐15% of a PV installations for a 5 km footprint and 5-­‐10% for a 50 km footprint; Energy losses from energy buffer transfer are negligible (well below 1%); Accurate forecasts can reduce mitigation costs by nearly 40%. The forecast advantage is found to be largest in the continental US where cloud structures are driven by moving fronts. Reducing dispersed generation’s variability instead of focusing on single installations would be considerably more cost effective when operationally possible. Mitigation costs are found to be highest in the southeastern US, particularly for longer variability time scale, also noting that differences between very different climatic environments are not very large. The present mitigation approach could be generalized and used as a driver for control systems, by exploiting high resolution satellite-­‐derived solar resource forecast data such as SolarAnywhere [19]. 29 REFERENCES [1] Hinkelman L., R. George and M. Sengupta, 2011: Differences between Along-Wind
and Cross-Wind Solar Variability. Proc. Solar 2011, American Solar Energy Society
Conf., Raleigh, NC
[2] Hoff T., & R. Perez (2012): Modeling PV Fleet Output Variability, Solar Energy 86,
8, 2177-2189
[3] Hoff, T. E., Perez, R. 2010. “Quantifying PV power Output Variability.” Solar
Energy 84 (2010) 1782–1793
[4] Jamaly, S., Bosch, J., Kleissl, J. 2012. “Aggregate Ramp Rates of Distributed
Photovoltaic Systems in San Diego County.” IEEE Transactions on Sustainable Energy,
in press
[5] Lave, M., J. Kleissl, Arias-Castro, E., High-frequency fluctuations in clear-sky index,
Solar Energy, doi:10.1016/j.solener.2011.06.031, 2011
[6] Lorenz E., T. Scheidsteger, J. Hurka, D. Heinemann and C. Kurz, (2011): Regional
PV power prediction for improved grid integration. Progress in Photovoltaics, 19, 7, 757771.
[7] Mills, A., Wiser, R. 2010. Implications of Wide-Area Geographic Diversity for ShortTerm Variability of Solar Power. Lawrence Berkeley National Laboratory Technical
Report LBNL-3884E.
[8] Murata, A., H. Yamaguchi, and K. Otani (2009): A Method of Estimating the Output
Fluctuation of Many Photovoltaic Power Generation Systems Dispersed in a Wide Area,
Electrical Engineering in Japan, Volume 166, No. 4, pp. 9-19
[9] Perez M., and V. Fthenakis, (2012): Quantifying Long Time Scale Solar Resource
Variability. Proc. WREF, Denver, CO.
[10] Perez, R., T. Hoff and S. Kivalov, (2011a): Spatial & temporal characteristics of
solar radiation variability. Proc. of International Solar Energy (ISES) World Congress,
Kassel, Germany
[11] Perez, R., Kivalov, S., Schlemmer, J., Hemker Jr., C. , Hoff, T. E. (2011b):
Parameterization of site-specific short-term irradiance variability, Solar Energy 85 (2011)
1343-1353
[12] Perez, R., Kivalov, S., Schlemmer, J., Hemker Jr., C. , Hoff, T. E. (2012): “Shortterm irradiance variability correlation as a function of distance.” Solar Energy 86, 8, pp.
2170-2176
[13] Wiemken E., H. G. Beyer, W. Heydenreich and K. Kiefer (2001): Power
Characteristics of PV ensembles: Experience from the combined power productivity of
100 grid-connected systems distributed over Germany. Solar Energy 70, 513-519
[14] Woyte, A., Belmans, R., Nijs, J. (2007): Fluctuations in instantaneous clearness
index. Solar Energy 81 (2), 195-206.
[15] Marcos J., L. Morroyo, E. Lorenzo and M. Garcia, (2012): Smoothing of PV power
fluctuations by geographical dispersion. Prog. Photovolt: Res. Appl. 2012; 20:226–237
[16] Perez, R., T. Hoff, (2013): Solar Resource Variability, in: Solar Resource
Assessment & Forecasting (Ed. J. Kleissl), Elsevier, 2013
[17] Yordanov, G., O. Mitdgard, O. and L. Norum (2013): Overirradiance (Cloud
Enhancement) Events at High Latitudes. IEEE Journal of Photovoltaics, 3, 1, 271-278.
30 [18] Germa, J.M., & M. Perez, (2012): Energy Storage: Technology, Applications &
trends. Cluster Maritime Français. 10/3/12
[19]
SolarAnywhere
(2013):
http://www.cleanpower.com/products/solaranywhere/solaranywhere-data /
[20] NOAA SURFRAD & ISIS Networks: http://www.esrl.noaa.gov
[21] Perez R. and T. Hoff (2013): Final Report on PV Variability Mitigation. GW
University Report on contract No. under contracts No. 1000178044 (in preparation)
31 APPENDIX 2 Complete result tables HANFORD Single Point
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.66
0.41
0.16
0.06
0.04
0.02
0.02
1.27
0.72
0.36
0.15
0.10
0.08
$ 614
$ 559
$ 446
$ 357
$ 314
$ 281
$ 262
0.18%
0.14%
0.12%
0.08%
0.06%
0.04%
0.04%
0.76
0.77
0.74
0.71
0.70
0.58
$ 607
$ 535
$ 450
$ 370
$ 347
$ 288
0.27%
0.19%
0.14%
0.10%
0.08%
0.07%
1.58
0.88
0.45
0.36
0.22
$ 654
$ 555
$ 375
$ 341
$ 300
0.30%
0.20%
0.14%
0.12%
0.09%
$ 641
$ 553
$ 438
$ 325
0.29%
0.19%
0.14%
0.11%
0.42 $ 406
0.46 $ 365
0.34 $ 251
0.24%
0.15%
0.09%
0.78
0.76
0.56
0.52
0.50
1.56
0.90
0.59
0.37
0.76
0.75
0.63
0.49
1.36
0.78
0.44
2.65
2.07
0.92
5.24
2.14
1.22
0.63
0.40
0.28
$ 1,043
$ 707
$ 619
$ 506
$ 414
$ 359
0.53%
0.32%
0.23%
0.15%
0.13%
0.11%
$ 965
$ 745
$ 634
$ 492
$ 438
0.53%
0.39%
0.25%
0.18%
0.14%
$ 914
$ 718
$ 620
$ 554
0.51%
0.38%
0.27%
0.20%
0.56 $ 826
0.57 $ 678
0.37 $ 360
0.50%
0.40%
0.18%
0.87
0.77
0.79
0.75
0.65
0.59
5.13
3.00
1.60
0.97
0.71
0.78
0.71
0.74
0.63
0.59
5.08
2.96
1.90
1.27
0.72
0.67
0.66
0.67
5.29
3.35
1.25
120-­‐minute ramps
0.35 $ 484
0.39 $ 443
0.30 $ 282
0.39%
0.30%
0.14%
32 0.35%
0.20%
0.17%
0.13%
0.10%
0.07%
0.07%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 990
$ 764
$ 514
$ 458
$ 447
$ 351
$ 327
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
1.14
1.05
0.77
0.78
0.85
0.77
0.72
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
2.53
1.25
0.58
0.30
0.17
0.07
0.06
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
0.94
0.94
0.88
0.79
0.72
0.69
0.64
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.77
4.83
4.39
0.55 $ 929
0.56 $ 781
0.49 $ 699
0.58%
0.48%
0.37%
HANFORD 1X1 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.38
0.18
0.06
0.02
0.01
0.01
0.00
1.12
0.39
0.20
0.11
0.05
0.03
0.54
0.49
0.46
0.39
0.34
0.32
0.26
$ 352
$ 284
$ 226
$ 173
$ 146
$ 131
$ 104
0.13%
0.10%
0.07%
0.04%
0.03%
0.02%
0.02%
0.86
0.66
0.57
0.51
0.40
0.35
$ 654
$ 416
$ 325
$ 267
$ 194
$ 159
0.21%
0.14%
0.10%
0.08%
0.06%
0.04%
1.23
0.66
0.27
0.18
0.10
1.51
0.80
0.37
0.21
0.67
0.58
0.47
0.43
0.33
$ 547
$ 423
$ 296
$ 255
$ 187
0.22%
0.17%
0.10%
0.08%
0.06%
1.31
0.90
0.47
0.68
0.58
0.47
0.35
$ 884
$ 668
$ 476
$ 333
0.23%
0.17%
0.12%
0.08%
0.55 $ 494
0.49 $ 410
0.35 $ 272
0.16%
0.13%
0.09%
2.34
1.96
0.84
4.01
1.71
0.94
0.41
0.27
0.14
$ 788
$ 528
$ 466
$ 319
$ 255
$ 196
0.32%
0.18%
0.14%
0.10%
0.08%
0.06%
$ 821
$ 610
$ 415
$ 356
$ 266
0.32%
0.20%
0.14%
0.12%
0.08%
$ 813
$ 673
$ 475
$ 332
0.38%
0.23%
0.18%
0.12%
0.63 $ 724
0.55 $ 593
0.42 $ 410
0.29%
0.25%
0.18%
0.69
0.57
0.60
0.47
0.40
0.34
4.84
2.68
1.33
0.91
0.46
0.67
0.58
0.46
0.43
0.36
4.44
2.95
1.61
0.89
0.64
0.60
0.48
0.37
3.40
2.51
1.38
120-­‐minute ramps
0.58 $ 602
0.51 $ 515
0.35 $ 309
0.23%
0.20%
0.11%
33 0.15%
0.12%
0.09%
0.06%
0.04%
0.03%
0.02%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 580
$ 471
$ 367
$ 286
$ 229
$ 198
$ 151
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.66
0.61
0.57
0.51
0.45
0.41
0.33
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.57
0.89
0.37
0.15
0.07
0.05
0.02
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.89
5.70
4.88
0.59 $ 962
0.51 $ 809
0.45 $ 705
0.38%
0.34%
0.22%
HANFORD 2X2 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.38
0.18
0.06
0.02
0.01
0.01
0.00
1.16
0.45
0.20
0.09
0.06
0.03
0.51
0.45
0.36
0.32
0.18
0.18
0.13
$ 338
$ 262
$ 179
$ 144
$ 75
$ 75
$ 53
0.12%
0.09%
0.06%
0.03%
0.01%
0.01%
0.01%
0.85
0.76
0.66
0.46
0.38
0.29
$ 654
$ 480
$ 367
$ 236
$ 190
$ 136
0.21%
0.14%
0.10%
0.07%
0.05%
0.03%
1.27
0.68
0.34
0.18
0.11
1.40
0.83
0.38
0.22
0.66
0.57
0.52
0.45
0.35
$ 551
$ 421
$ 334
$ 268
$ 197
0.21%
0.16%
0.11%
0.08%
0.06%
1.33
0.91
0.48
0.65
0.57
0.46
0.34
$ 834
$ 656
$ 465
$ 333
0.22%
0.17%
0.12%
0.08%
0.57 $ 508
0.51 $ 427
0.36 $ 275
0.16%
0.13%
0.08%
1.86
1.48
0.87
3.94
1.85
0.96
0.41
0.28
0.14
$ 820
$ 543
$ 443
$ 331
$ 285
$ 206
0.31%
0.18%
0.14%
0.09%
0.08%
0.05%
$ 830
$ 597
$ 426
$ 363
$ 270
0.32%
0.20%
0.14%
0.12%
0.08%
$ 871
$ 577
$ 470
$ 326
0.38%
0.21%
0.17%
0.12%
0.66 $ 748
0.57 $ 611
0.44 $ 422
0.29%
0.25%
0.18%
0.73
0.57
0.56
0.49
0.45
0.36
4.80
2.62
1.35
0.92
0.47
0.69
0.58
0.47
0.44
0.37
4.36
2.25
1.65
0.90
0.72
0.54
0.47
0.36
3.44
2.52
1.39
120-­‐minute ramps
0.56 $ 547
0.49 $ 463
0.36 $ 312
0.19%
0.16%
0.11%
34 0.14%
0.11%
0.08%
0.05%
0.03%
0.03%
0.02%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 569
$ 460
$ 319
$ 243
$ 175
$ 175
$ 123
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.64
0.60
0.49
0.42
0.35
0.35
0.26
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.57
0.88
0.32
0.15
0.05
0.05
0.02
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.02
4.79
3.21
0.53 $ 858
0.45 $ 698
0.35 $ 511
0.25%
0.21%
0.17%
HANFORD 5X5 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.31
0.16
0.05
0.01
0.00
0.00
0.00
1.08
0.37
0.20
0.08
0.05
0.02
0.52
0.45
0.25
0.19
0.11
0.11
0.11
$ 329
$ 260
$ 132
$ 84
$ 43
$ 43
$ 43
0.10%
0.07%
0.04%
0.01%
0.00%
0.00%
0.00%
0.85
0.73
0.64
0.42
0.28
0.18
$ 641
$ 450
$ 359
$ 215
$ 141
$ 86
0.19%
0.12%
0.08%
0.05%
0.04%
0.02%
1.21
0.65
0.26
0.18
0.10
1.31
0.78
0.36
0.21
0.66
0.56
0.45
0.41
0.31
$ 537
$ 412
$ 283
$ 243
$ 176
0.21%
0.15%
0.09%
0.07%
0.05%
1.27
0.87
0.44
0.65
0.56
0.46
0.33
$ 822
$ 646
$ 462
$ 320
0.21%
0.16%
0.11%
0.07%
0.52 $ 469
0.46 $ 389
0.32 $ 247
0.16%
0.13%
0.08%
1.81
1.44
0.81
3.76
1.59
0.79
0.40
0.27
0.13
$ 804
$ 511
$ 402
$ 309
$ 249
$ 158
0.30%
0.17%
0.12%
0.08%
0.07%
0.04%
$ 827
$ 599
$ 397
$ 339
$ 256
0.32%
0.19%
0.13%
0.11%
0.07%
$ 858
$ 576
$ 459
$ 329
0.37%
0.20%
0.17%
0.11%
0.60 $ 707
0.53 $ 583
0.39 $ 391
0.28%
0.24%
0.17%
0.73
0.56
0.52
0.46
0.39
0.26
4.67
2.63
1.30
0.89
0.45
0.70
0.57
0.44
0.41
0.35
4.21
2.25
1.59
0.87
0.72
0.54
0.46
0.37
3.41
2.55
1.38
120-­‐minute ramps
0.55 $ 537
0.49 $ 453
0.35 $ 300
0.19%
0.16%
0.11%
35 0.13%
0.10%
0.06%
0.04%
0.01%
0.01%
0.01%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 505
$ 423
$ 286
$ 177
$ 93
$ 93
$ 93
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.55
0.55
0.44
0.30
0.19
0.19
0.19
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.50
0.81
0.29
0.12
0.02
0.02
0.02
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.00
4.86
3.24
0.53 $ 856
0.46 $ 712
0.35 $ 515
0.24%
0.21%
0.17%
HANFORD 8X8 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.29
0.15
0.04
0.01
0.00
0.00
0.00
1.08
0.34
0.18
0.07
0.04
0.02
0.51
0.44
0.23
0.16
0.10
0.10
0.10
$ 318
$ 249
$ 116
$ 70
$ 39
$ 39
$ 39
0.09%
0.06%
0.03%
0.01%
0.00%
0.00%
0.00%
0.80
0.68
0.60
0.38
0.25
0.12
$ 611
$ 417
$ 334
$ 196
$ 127
$ 58
0.19%
0.11%
0.07%
0.04%
0.03%
0.01%
1.19
0.57
0.25
0.17
0.09
1.28
0.77
0.35
0.19
0.61
0.49
0.41
0.37
0.28
$ 508
$ 359
$ 265
$ 226
$ 157
0.20%
0.14%
0.08%
0.06%
0.04%
1.24
0.86
0.40
0.60
0.52
0.40
0.28
$ 763
$ 604
$ 418
$ 274
0.21%
0.15%
0.10%
0.07%
0.50 $ 452
0.45 $ 376
0.29 $ 225
0.15%
0.12%
0.08%
1.80
1.44
0.80
3.95
1.58
0.78
0.40
0.27
0.13
$ 792
$ 484
$ 372
$ 289
$ 240
$ 150
0.22%
0.16%
0.11%
0.08%
0.06%
0.04%
$ 806
$ 559
$ 373
$ 334
$ 253
0.31%
0.19%
0.13%
0.10%
0.07%
$ 838
$ 616
$ 440
$ 296
0.37%
0.22%
0.16%
0.11%
0.59 $ 702
0.52 $ 581
0.39 $ 387
0.28%
0.24%
0.17%
0.69
0.52
0.48
0.42
0.37
0.24
4.59
2.57
1.28
0.87
0.45
0.68
0.53
0.40
0.40
0.34
4.13
2.82
1.58
0.86
0.70
0.53
0.43
0.32
3.41
2.54
1.36
120-­‐minute ramps
0.55 $ 531
0.48 $ 453
0.35 $ 298
0.19%
0.16%
0.10%
36 0.12%
0.09%
0.05%
0.03%
0.01%
0.01%
0.01%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 486
$ 388
$ 258
$ 144
$ 85
$ 85
$ 85
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.54
0.50
0.40
0.25
0.17
0.17
0.17
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.40
0.75
0.26
0.09
0.02
0.02
0.02
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.01
4.85
3.24
0.53 $ 852
0.46 $ 711
0.35 $ 513
0.24%
0.20%
0.16%
HANFORD 13X13 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.26
0.11
0.03
0.00
0.00
0.00
0.00
0.97
0.31
0.13
0.06
0.03
0.00
0.34
0.27
0.19
0.12
0.09
0.09
0.00
$ 226
$ 159
$ 95
$ 53
$ 34
$ 34
$ 0
0.08%
0.05%
0.02%
0.00%
0.00%
0.00%
0.00%
0.71
0.49
0.37
0.23
0.16
0.00
$ 545
$ 316
$ 213
$ 123
$ 82
$ 0
0.18%
0.10%
0.06%
0.04%
0.02%
0.00%
1.05
0.52
0.23
0.15
0.07
1.22
0.51
0.33
0.18
0.54
0.44
0.31
0.27
0.19
$ 450
$ 322
$ 206
$ 172
$ 111
0.19%
0.13%
0.07%
0.05%
0.03%
1.19
0.82
0.38
0.55
0.45
0.38
0.26
$ 714
$ 497
$ 395
$ 255
0.20%
0.12%
0.10%
0.06%
0.46 $ 424
0.40 $ 348
0.24 $ 196
0.15%
0.12%
0.07%
1.73
1.40
0.79
3.57
1.48
0.74
0.38
0.25
0.00
$ 699
$ 425
$ 348
$ 275
$ 225
$ 0
0.21%
0.15%
0.10%
0.07%
0.05%
0.00%
$ 765
$ 534
$ 346
$ 321
$ 243
0.31%
0.18%
0.12%
0.10%
0.06%
$ 809
$ 519
$ 422
$ 281
0.36%
0.19%
0.16%
0.10%
0.56 $ 679
0.51 $ 574
0.38 $ 379
0.27%
0.24%
0.16%
0.61
0.45
0.44
0.40
0.34
0.00
4.45
2.51
1.21
0.82
0.42
0.64
0.49
0.37
0.39
0.33
3.98
2.16
1.49
0.81
0.68
0.48
0.42
0.30
3.49
2.59
1.38
120-­‐minute ramps
0.54 $ 518
0.48 $ 440
0.35 $ 296
0.19%
0.15%
0.10%
37 0.12%
0.08%
0.05%
0.02%
0.01%
0.01%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 414
$ 345
$ 242
$ 100
$ 76
$ 76
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.44
0.45
0.37
0.17
0.15
0.15
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.32
0.66
0.25
0.07
0.02
0.02
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.08
4.88
3.26
0.52 $ 844
0.47 $ 720
0.35 $ 513
0.23%
0.20%
0.16%
HANFORD 20X20 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.22
0.08
0.02
0.00
0.00
0.00
0.00
0.91
0.25
0.10
0.05
0.01
0.00
0.31
0.20
0.13
0.09
0.07
0.07
0.00
$ 202
$ 119
$ 66
$ 35
$ 27
$ 27
$ 0
0.07%
0.04%
0.01%
0.00%
0.00%
0.00%
0.00%
0.70
0.43
0.28
0.20
0.06
0.00
$ 532
$ 272
$ 158
$ 107
$ 29
$ 0
0.16%
0.08%
0.04%
0.03%
0.01%
0.00%
0.99
0.38
0.20
0.13
0.06
1.16
0.49
0.32
0.17
0.52
0.43
0.27
0.22
0.14
$ 432
$ 293
$ 180
$ 141
$ 83
0.18%
0.11%
0.06%
0.05%
0.03%
1.14
0.80
0.36
0.53
0.42
0.36
0.24
$ 685
$ 467
$ 373
$ 237
0.19%
0.11%
0.09%
0.05%
0.40 $ 377
0.35 $ 314
0.23 $ 185
0.14%
0.11%
0.07%
1.67
1.36
0.77
3.29
1.31
0.58
0.35
0.12
0.00
$ 629
$ 400
$ 306
$ 248
$ 116
$ 0
0.20%
0.14%
0.08%
0.06%
0.03%
0.00%
$ 706
$ 476
$ 325
$ 298
$ 227
0.31%
0.16%
0.12%
0.09%
0.06%
$ 739
$ 507
$ 416
$ 267
0.36%
0.19%
0.15%
0.10%
0.53 $ 659
0.48 $ 552
0.35 $ 362
0.26%
0.23%
0.16%
0.53
0.43
0.41
0.36
0.18
0.00
4.38
2.18
1.14
0.77
0.39
0.56
0.45
0.35
0.36
0.31
3.91
2.10
1.45
0.75
0.59
0.47
0.41
0.29
3.50
2.59
1.37
120-­‐minute ramps
0.51 $ 489
0.45 $ 424
0.33 $ 284
0.18%
0.15%
0.10%
38 0.11%
0.07%
0.04%
0.01%
0.01%
0.01%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 398
$ 315
$ 212
$ 74
$ 63
$ 63
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.43
0.41
0.32
0.13
0.12
0.12
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.22
0.56
0.23
0.04
0.02
0.02
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.10
4.88
3.26
0.51 $ 841
0.46 $ 717
0.34 $ 510
0.23%
0.19%
0.16%
HANFORD 30X30 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.20
0.07
0.01
0.00
0.00
0.00
0.00
0.80
0.24
0.09
0.03
0.00
0.00
0.26
0.17
0.07
0.04
0.04
0.00
0.00
$ 175
$ 99
$ 37
$ 18
$ 18
$ 0
$ 0
0.06%
0.03%
0.01%
0.00%
0.00%
0.00%
0.00%
0.64
0.38
0.23
0.11
0.00
0.00
$ 477
$ 240
$ 135
$ 60
$ 0
$ 0
0.15%
0.07%
0.03%
0.01%
0.00%
0.00%
0.96
0.37
0.18
0.12
0.05
1.12
0.47
0.30
0.16
0.49
0.37
0.24
0.19
0.11
$ 407
$ 259
$ 159
$ 124
$ 67
0.17%
0.10%
0.05%
0.04%
0.02%
1.09
0.78
0.34
0.49
0.36
0.30
0.20
$ 645
$ 408
$ 325
$ 205
0.18%
0.10%
0.08%
0.05%
0.39 $ 364
0.34 $ 303
0.23 $ 179
0.14%
0.11%
0.06%
1.61
1.32
0.75
2.98
1.27
0.54
0.22
0.00
0.00
$ 563
$ 387
$ 272
$ 178
$ 0
$ 0
0.20%
0.13%
0.08%
0.04%
0.00%
0.00%
$ 618
$ 462
$ 318
$ 269
$ 202
0.30%
0.16%
0.11%
0.08%
0.05%
$ 622
$ 490
$ 401
$ 257
0.24%
0.18%
0.14%
0.09%
0.47 $ 609
0.43 $ 509
0.34 $ 353
0.26%
0.22%
0.15%
0.48
0.42
0.35
0.27
0.00
0.00
4.31
2.11
1.10
0.74
0.37
0.46
0.44
0.34
0.31
0.27
3.46
2.02
1.40
0.72
0.48
0.45
0.40
0.28
3.39
2.51
1.35
120-­‐minute ramps
0.46 $ 454
0.41 $ 391
0.29 $ 258
0.18%
0.14%
0.09%
39 0.10%
0.06%
0.03%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 373
$ 279
$ 161
$ 44
$ 44
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.41
0.37
0.25
0.08
0.08
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.11
0.51
0.16
0.02
0.02
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
5.94
4.76
3.19
0.49 $ 806
0.44 $ 690
0.33 $ 496
0.22%
0.19%
0.15%
HANFORD 50X50 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.16
0.04
0.00
0.00
0.00
0.00
0.00
0.73
0.19
0.05
0.01
0.00
0.00
0.22
0.11
0.03
0.00
0.00
0.00
0.00
$ 146
$ 65
$ 12
$ 0
$ 0
$ 0
$ 0
0.04%
0.02%
0.00%
0.00%
0.00%
0.00%
0.00%
0.56
0.31
0.15
0.04
0.00
0.00
$ 426
$ 199
$ 86
$ 19
$ 0
$ 0
0.13%
0.05%
0.02%
0.01%
0.00%
0.00%
0.83
0.27
0.09
0.04
0.00
1.03
0.44
0.26
0.12
0.43
0.26
0.16
0.09
0.00
$ 355
$ 185
$ 101
$ 55
$ 0
0.14%
0.07%
0.03%
0.02%
0.00%
1.04
0.75
0.33
0.44
0.31
0.24
0.16
$ 575
$ 354
$ 259
$ 160
0.16%
0.09%
0.06%
0.03%
0.37 $ 344
0.32 $ 283
0.20 $ 160
0.12%
0.09%
0.05%
1.51
1.24
0.66
2.46
0.98
0.41
0.10
0.00
0.00
$ 499
$ 306
$ 198
$ 78
$ 0
$ 0
0.19%
0.11%
0.06%
0.02%
0.00%
0.00%
$ 541
$ 377
$ 227
$ 149
$ 0
0.20%
0.13%
0.07%
0.04%
0.00%
$ 544
$ 442
$ 354
$ 222
0.21%
0.17%
0.13%
0.08%
0.40 $ 538
0.40 $ 471
0.31 $ 321
0.25%
0.21%
0.14%
0.44
0.33
0.26
0.11
0.00
0.00
3.53
1.62
0.68
0.35
0.00
0.42
0.37
0.26
0.19
0.00
2.82
1.84
1.27
0.66
0.44
0.41
0.35
0.24
3.17
2.28
1.22
120-­‐minute ramps
0.39 $ 398
0.33 $ 335
0.28 $ 243
0.17%
0.13%
0.08%
40 0.09%
0.05%
0.01%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 302
$ 220
$ 74
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.33
0.29
0.11
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.89
0.42
0.08
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
4.13
2.95
2.95
0.29 $ 518
0.29 $ 440
0.29 $ 440
0.18%
0.14%
0.14%
HANFORD 80X80 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.09
0.01
0.00
0.00
0.00
0.00
0.00
0.61
0.11
0.01
0.00
0.00
0.00
0.18
0.06
0.00
0.00
0.00
0.00
0.00
$ 110
$ 31
$ 0
$ 0
$ 0
$ 0
$ 0
0.03%
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
0.43
0.25
0.06
0.00
0.00
0.00
$ 331
$ 152
$ 32
$ 0
$ 0
$ 0
0.10%
0.04%
0.01%
0.00%
0.00%
0.00%
0.73
0.24
0.03
0.03
0.00
0.90
0.22
0.09
0.00
0.34
0.21
0.08
0.08
0.00
$ 291
$ 150
$ 48
$ 48
$ 0
0.12%
0.05%
0.01%
0.01%
0.00%
0.94
0.30
0.30
0.35
0.18
0.15
0.00
$ 477
$ 204
$ 140
$ 1
0.14%
0.05%
0.03%
0.00%
0.33 $ 310
0.16 $ 132
0.16 $ 132
0.11%
0.04%
0.04%
1.51
1.17
0.55
2.29
0.76
0.20
0.00
0.00
0.00
$ 414
$ 230
$ 105
$ 0
$ 0
$ 0
0.17%
0.08%
0.03%
0.00%
0.00%
0.00%
$ 424
$ 277
$ 113
$ 113
$ 0
0.17%
0.10%
0.03%
0.03%
0.00%
$ 460
$ 302
$ 187
$ 0
0.19%
0.11%
0.07%
0.00%
0.38 $ 507
0.33 $ 406
0.24 $ 262
0.23%
0.19%
0.12%
0.34
0.25
0.14
0.00
0.00
0.00
2.89
1.24
0.33
0.33
0.00
0.32
0.26
0.13
0.13
0.00
2.65
1.22
0.64
0.00
0.35
0.28
0.19
0.00
3.00
2.15
1.16
120-­‐minute ramps
0.46 $ 398
0.27 $ 281
0.27 $ 220
0.19%
0.12%
0.07%
41 0.07%
0.02%
0.00%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 234
$ 128
$ 0
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.25
0.17
0.00
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.72
0.21
0.00
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
3.75
2.61
2.61
0.29 $ 495
0.24 $ 378
0.24 $ 378
0.16%
0.13%
0.13%
HANFORD 130X130 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.04
0.01
0.00
0.00
0.00
0.00
0.00
0.49
0.05
0.01
0.00
0.00
0.00
0.12
0.05
0.00
0.00
0.00
0.00
0.00
$ 70
$ 29
$ 0
$ 0
$ 0
$ 0
$ 0
0.01%
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
0.30
0.18
0.05
0.00
0.00
0.00
$ 243
$ 100
$ 29
$ 0
$ 0
$ 0
0.08%
0.02%
0.01%
0.00%
0.00%
0.00%
0.62
0.14
0.02
0.00
0.00
0.69
0.18
0.08
0.00
0.25
0.18
0.08
0.00
0.00
$ 225
$ 121
$ 43
$ 0
$ 0
0.11%
0.03%
0.01%
0.00%
0.00%
0.77
0.24
0.00
0.27
0.17
0.14
0.00
$ 361
$ 184
$ 129
$ 1
0.11%
0.04%
0.02%
0.00%
0.26 $ 252
0.12 $ 100
0.00 $ 0
0.09%
0.03%
0.00%
1.51
1.11
0.00
2.32
0.48
0.19
0.00
0.00
0.00
$ 372
$ 151
$ 100
$ 0
$ 0
$ 0
0.15%
0.04%
0.02%
0.00%
0.00%
0.00%
$ 374
$ 199
$ 107
$ 0
$ 0
0.14%
0.07%
0.03%
0.00%
0.00%
$ 446
$ 258
$ 160
$ 0
0.18%
0.09%
0.05%
0.00%
0.25 $ 334
0.18 $ 221
0.00 $ 0
0.16%
0.10%
0.00%
0.28
0.17
0.13
0.00
0.00
0.00
2.59
0.93
0.32
0.00
0.00
0.28
0.18
0.12
0.00
0.00
2.86
1.19
0.62
0.00
0.32
0.22
0.15
0.00
2.01
1.11
0.00
120-­‐minute ramps
0.37 $ 389
0.20 $ 232
0.00 $ 1
0.16%
0.10%
0.00%
42 0.04%
0.02%
0.00%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 163
$ 121
$ 0
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.18
0.16
0.00
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.48
0.21
0.00
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
3.67
2.47
0.00
0.26 $ 467
0.20 $ 335
0.00 $ 1
0.16%
0.10%
0.00%
HANFORD 200X200 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.11
0.02
0.00
0.00
0.00
0.00
0.04
0.02
0.00
0.00
0.00
0.00
0.00
$ 23
$ 12
$ 0
$ 0
$ 0
$ 0
$ 0
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.17
0.05
0.02
0.00
0.00
0.00
$ 107
$ 29
$ 8
$ 0
$ 0
$ 0
0.03%
0.01%
0.00%
0.00%
0.00%
0.00%
0.44
0.03
0.00
0.00
0.00
0.53
0.05
0.00
0.00
0.17
0.09
0.00
0.00
0.00
$ 155
$ 53
$ 0
$ 0
$ 0
0.08%
0.01%
0.00%
0.00%
0.00%
0.37
0.15
0.00
0.18
0.09
0.00
0.00
$ 255
$ 84
$ 1
$ 1
0.09%
0.02%
0.00%
0.00%
0.15 $ 132
0.07 $ 63
0.00 $ 0
0.05%
0.03%
0.00%
1.13
0.93
0.00
2.37
0.27
0.09
0.00
0.00
0.00
$ 358
$ 94
$ 43
$ 0
$ 0
$ 0
0.13%
0.02%
0.01%
0.00%
0.00%
0.00%
$ 235
$ 124
$ 0
$ 0
$ 0
0.09%
0.04%
0.00%
0.00%
0.00%
$ 252
$ 132
$ 0
$ 0
0.11%
0.04%
0.00%
0.00%
0.14 $ 182
0.14 $ 182
0.00 $ 0
0.08%
0.08%
0.00%
0.26
0.11
0.05
0.00
0.00
0.00
1.65
0.60
0.00
0.00
0.00
0.17
0.11
0.00
0.00
0.00
1.62
0.59
0.00
0.00
0.18
0.11
0.00
0.00
1.06
1.06
0.00
120-­‐minute ramps
0.25 $ 264
0.17 $ 193
0.00 $ 1
0.11%
0.08%
0.00%
43 0.02%
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 99
$ 67
$ 0
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.12
0.09
0.00
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.24
0.13
0.00
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
2.27
2.27
0.00
0.20 $ 318
0.20 $ 318
0.00 $ 1
0.08%
0.08%
0.00%
GOODWIN CREEK Single Point
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.80
0.39
0.16
0.08
0.04
0.02
0.02
2.00
0.73
0.36
0.18
0.11
0.08
0.87
0.93
0.85
0.79
0.75
0.71
0.65
$ 696
$ 617
$ 483
$ 406
$ 351
$ 314
$ 280
0.37%
0.30%
0.23%
0.18%
0.13%
0.11%
0.09%
0.78
0.77
0.73
0.67
0.63
0.56
$ 858
$ 621
$ 501
$ 405
$ 356
$ 304
0.46%
0.32%
0.25%
0.19%
0.16%
0.14%
2.68
1.05
0.51
0.32
0.22
2.28
1.09
0.64
0.42
0.65
0.64
0.61
0.57
0.54
$ 858
$ 603
$ 475
$ 405
$ 356
0.49%
0.33%
0.24%
0.19%
0.16%
2.44
1.47
0.97
0.59
0.53
0.47
0.45
$ 760
$ 535
$ 419
$ 361
0.43%
0.30%
0.23%
0.19%
0.62 $ 798
0.52 $ 590
0.44 $ 457
0.41%
0.31%
0.24%
3.72
2.75
1.91
5.98
3.18
1.63
0.75
0.45
0.30
$ 1,511
$ 1,105
$ 807
$ 602
$ 504
$ 453
0.74%
0.49%
0.36%
0.27%
0.23%
0.19%
$ 1,440
$ 1,146
$ 816
$ 654
$ 554
0.73%
0.51%
0.37%
0.29%
0.24%
$ 1,416
$ 1,123
$ 862
$ 678
0.70%
0.48%
0.37%
0.30%
0.77 $ 1,347
0.71 $ 1,121
0.63 $ 919
0.66%
0.48%
0.40%
0.95
0.89
0.80
0.73
0.69
0.67
6.32
4.19
2.23
1.35
0.90
0.83
0.77
0.68
0.64
0.61
6.31
4.12
2.63
1.78
0.80
0.76
0.67
0.58
5.92
4.44
3.33
120-­‐minute ramps
0.67 $ 1,012
0.57 $ 805
0.52 $ 651
0.52%
0.42%
0.34%
44 0.53%
0.41%
0.31%
0.25%
0.20%
0.16%
0.14%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 1,234
$ 924
$ 774
$ 579
$ 462
$ 411
$ 364
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
1.00
0.95
1.04
0.89
0.81
0.77
0.72
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
3.49
1.73
0.72
0.34
0.16
0.10
0.06
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.63
7.15
4.80
0.72 $ 1,593
0.65 $ 1,367
0.56 $ 1,036
0.82%
0.65%
0.47%
GOODWIN CREEK 1X1 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.48
0.22
0.07
0.03
0.02
0.01
0.00
0.55
0.54
0.52
0.48
0.42
0.31
0.24
1.54
0.59
0.27
0.13
0.06
0.03
$ 436
$ 356
$ 281
$ 230
$ 189
$ 134
$ 99
0.22%
0.17%
0.11%
0.08%
0.06%
0.04%
0.03%
1.76
0.83
0.43
0.31
0.11
0.86
0.74
0.62
0.49
0.42
0.33
$ 856
$ 575
$ 418
$ 296
$ 231
$ 170
0.40%
0.26%
0.19%
0.14%
0.10%
0.06%
$ 717
$ 516
$ 399
$ 362
$ 182
0.42%
0.29%
0.20%
0.18%
0.10%
$ 1,082
$ 710
$ 507
$ 335
0.42%
0.27%
0.18%
0.11%
0.57 $ 742
0.55 $ 655
0.40 $ 375
0.38%
0.33%
0.16%
0.64
0.57
0.51
0.50
0.28
2.25
0.97
0.50
0.24
0.56
0.47
0.38
0.29
2.27
1.74
0.60
3.61
3.13
2.21
5.48
2.22
1.11
0.55
0.28
0.14
$ 1,271
$ 829
$ 580
$ 440
$ 319
$ 244
0.57%
0.38%
0.28%
0.20%
0.14%
0.10%
$ 1,235
$ 968
$ 685
$ 584
$ 342
0.64%
0.43%
0.31%
0.27%
0.14%
$ 1,291
$ 999
$ 702
$ 465
0.67%
0.43%
0.30%
0.20%
0.72 $ 1,252
0.71 $ 1,157
0.53 $ 641
0.61%
0.58%
0.34%
0.79
0.73
0.61
0.55
0.45
0.38
5.96
3.74
1.87
1.39
0.48
0.75
0.70
0.62
0.56
0.41
5.45
3.67
1.85
0.95
0.78
0.67
0.59
0.45
5.51
4.73
1.75
120-­‐minute ramps
0.65 $ 982
0.62 $ 892
0.55 $ 716
0.51%
0.45%
0.36%
45 0.29%
0.22%
0.15%
0.11%
0.08%
0.06%
0.04%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 816
$ 622
$ 433
$ 347
$ 300
$ 211
$ 142
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.73
0.69
0.60
0.55
0.52
0.39
0.28
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
2.00
0.98
0.38
0.18
0.10
0.05
0.03
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.37
7.33
4.56
0.69 $ 1,532
0.69 $ 1,420
0.47 $ 928
0.80%
0.77%
0.39%
GOODWIN CREEK 2X2 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.47
0.22
0.07
0.03
0.01
0.01
0.00
1.53
0.57
0.26
0.12
0.06
0.03
$ 422
$ 308
$ 231
$ 185
$ 132
$ 104
$ 69
0.22%
0.16%
0.10%
0.06%
0.03%
0.03%
0.02%
0.85
0.74
0.61
0.48
0.37
0.27
$ 849
$ 569
$ 408
$ 288
$ 206
$ 142
0.40%
0.25%
0.18%
0.14%
0.09%
0.05%
1.75
0.83
0.42
0.31
0.11
$ 715
$ 509
$ 392
$ 354
$ 171
0.41%
0.29%
0.20%
0.17%
0.10%
$ 1,083
$ 708
$ 515
$ 337
0.42%
0.27%
0.18%
0.11%
0.57 $ 741
0.55 $ 656
0.41 $ 377
0.38%
0.33%
0.16%
0.64
0.56
0.50
0.48
0.26
2.23
0.96
0.49
0.24
0.57
0.47
0.40
0.29
2.26
1.74
0.61
3.58
3.11
2.20
5.07
2.22
1.10
0.55
0.28
0.14
$ 1,240
$ 835
$ 590
$ 444
$ 324
$ 217
0.66%
0.38%
0.27%
0.19%
0.14%
0.09%
$ 1,208
$ 969
$ 688
$ 588
$ 337
0.63%
0.43%
0.31%
0.26%
0.14%
$ 1,360
$ 992
$ 691
$ 457
0.53%
0.43%
0.30%
0.20%
0.72 $ 1,253
0.71 $ 1,157
0.54 $ 643
0.61%
0.58%
0.34%
0.81
0.74
0.62
0.56
0.46
0.33
5.70
3.73
1.87
1.39
0.47
0.75
0.70
0.62
0.57
0.41
6.29
3.67
1.85
0.94
0.75
0.66
0.57
0.44
5.51
4.72
1.74
120-­‐minute ramps
0.65 $ 978
0.62 $ 889
0.55 $ 713
0.51%
0.45%
0.36%
46 0.31%
0.22%
0.14%
0.10%
0.06%
0.05%
0.03%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 823
$ 617
$ 436
$ 349
$ 248
$ 194
$ 119
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.74
0.68
0.60
0.56
0.44
0.36
0.23
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
2.00
0.99
0.37
0.18
0.08
0.05
0.03
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
0.53
0.45
0.41
0.37
0.30
0.24
0.17
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.22
7.18
4.54
0.69 $ 1,513
0.68 $ 1,402
0.47 $ 926
0.80%
0.77%
0.38%
GOODWIN CREEK 3X3 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.48
0.21
0.07
0.03
0.01
0.00
0.00
1.52
0.58
0.26
0.12
0.06
0.03
0.54
0.44
0.35
0.28
0.18
0.10
0.00
$ 424
$ 299
$ 198
$ 142
$ 85
$ 42
$ 0
0.21%
0.15%
0.09%
0.05%
0.03%
0.01%
0.00%
0.87
0.74
0.62
0.42
0.35
0.25
$ 856
$ 573
$ 411
$ 260
$ 194
$ 132
0.40%
0.25%
0.18%
0.13%
0.08%
0.05%
1.75
0.83
0.42
0.31
0.11
2.23
0.96
0.50
0.24
0.64
0.57
0.51
0.49
0.27
$ 713
$ 516
$ 398
$ 358
$ 177
0.41%
0.29%
0.20%
0.17%
0.09%
2.26
1.75
0.60
0.55
0.46
0.39
0.29
$ 1,069
$ 705
$ 507
$ 336
0.41%
0.27%
0.17%
0.11%
0.57 $ 740
0.55 $ 654
0.40 $ 371
0.38%
0.32%
0.16%
3.58
3.11
2.20
5.10
2.23
1.11
0.55
0.28
0.14
$ 1,237
$ 828
$ 579
$ 438
$ 311
$ 225
0.66%
0.38%
0.27%
0.19%
0.14%
0.09%
$ 1,233
$ 966
$ 684
$ 583
$ 337
0.64%
0.43%
0.31%
0.26%
0.14%
$ 1,299
$ 997
$ 701
$ 466
0.67%
0.43%
0.30%
0.20%
0.72 $ 1,253
0.71 $ 1,157
0.53 $ 641
0.61%
0.57%
0.34%
0.80
0.73
0.61
0.55
0.43
0.35
5.95
3.73
1.87
1.39
0.47
0.75
0.70
0.61
0.56
0.41
5.51
3.67
1.85
0.95
0.78
0.67
0.59
0.45
5.51
4.72
1.75
120-­‐minute ramps
0.65 $ 978
0.62 $ 889
0.55 $ 711
0.50%
0.44%
0.36%
47 0.31%
0.22%
0.14%
0.10%
0.06%
0.02%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 807
$ 597
$ 421
$ 333
$ 217
$ 94
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.72
0.65
0.58
0.53
0.38
0.17
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.98
0.96
0.37
0.18
0.08
0.03
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.35
7.31
4.55
0.69 $ 1,531
0.69 $ 1,419
0.47 $ 928
0.80%
0.76%
0.38%
GOODWIN CREEK 5X5 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.47
0.21
0.06
0.02
0.01
0.00
0.00
1.52
0.57
0.26
0.12
0.06
0.03
0.53
0.43
0.27
0.22
0.11
0.00
0.00
$ 416
$ 294
$ 155
$ 109
$ 54
$ 0
$ 0
0.20%
0.14%
0.08%
0.03%
0.02%
0.00%
0.00%
0.84
0.74
0.60
0.37
0.29
0.19
$ 840
$ 568
$ 403
$ 235
$ 163
$ 101
0.39%
0.24%
0.16%
0.12%
0.07%
0.04%
1.75
0.83
0.42
0.31
0.10
1.99
0.95
0.50
0.24
0.63
0.57
0.51
0.48
0.26
$ 702
$ 514
$ 395
$ 351
$ 169
0.40%
0.28%
0.19%
0.16%
0.09%
2.26
1.75
0.59
0.55
0.46
0.39
0.29
$ 1,021
$ 698
$ 511
$ 339
0.39%
0.26%
0.17%
0.10%
0.56 $ 732
0.54 $ 646
0.39 $ 362
0.38%
0.32%
0.16%
3.46
2.99
2.11
5.09
2.22
1.10
0.55
0.28
0.14
$ 1,231
$ 824
$ 573
$ 434
$ 309
$ 197
0.67%
0.39%
0.27%
0.18%
0.13%
0.08%
$ 1,203
$ 966
$ 684
$ 583
$ 332
0.62%
0.41%
0.30%
0.25%
0.13%
$ 1,334
$ 998
$ 702
$ 467
0.52%
0.42%
0.30%
0.19%
0.72 $ 1,252
0.71 $ 1,157
0.53 $ 641
0.61%
0.57%
0.34%
0.80
0.72
0.60
0.54
0.43
0.29
5.71
3.73
1.87
1.39
0.47
0.74
0.70
0.61
0.56
0.40
6.01
3.66
1.85
0.94
0.76
0.67
0.59
0.45
5.50
4.72
1.75
120-­‐minute ramps
0.65 $ 963
0.62 $ 874
0.55 $ 699
0.50%
0.44%
0.35%
48 0.30%
0.21%
0.13%
0.08%
0.05%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 801
$ 573
$ 393
$ 280
$ 187
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.71
0.62
0.54
0.44
0.31
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.97
0.96
0.35
0.15
0.08
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.35
7.31
4.54
0.69 $ 1,530
0.69 $ 1,419
0.47 $ 926
0.80%
0.77%
0.38%
GOODWIN CREEK 8X8 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.46
0.20
0.05
0.01
0.00
0.00
0.00
1.51
0.56
0.25
0.11
0.05
0.02
0.51
0.39
0.22
0.14
0.00
0.00
0.00
$ 402
$ 271
$ 130
$ 72
$ 0
$ 0
$ 0
0.19%
0.13%
0.06%
0.02%
0.00%
0.00%
0.00%
0.82
0.71
0.57
0.36
0.22
0.13
$ 824
$ 552
$ 380
$ 225
$ 125
$ 72
0.38%
0.22%
0.15%
0.10%
0.06%
0.03%
1.74
0.82
0.42
0.30
0.10
1.98
0.94
0.49
0.24
0.60
0.55
0.49
0.45
0.23
$ 679
$ 501
$ 380
$ 333
$ 152
0.39%
0.27%
0.18%
0.15%
0.08%
2.25
1.74
0.58
0.55
0.46
0.39
0.28
$ 1,020
$ 690
$ 507
$ 332
0.38%
0.26%
0.16%
0.10%
0.55 $ 719
0.52 $ 634
0.38 $ 353
0.37%
0.32%
0.16%
3.44
2.97
2.09
5.03
2.22
1.10
0.41
0.28
0.14
$ 1,215
$ 817
$ 569
$ 373
$ 301
$ 182
0.66%
0.37%
0.26%
0.15%
0.11%
0.07%
$ 1,211
$ 965
$ 685
$ 456
$ 312
0.62%
0.40%
0.29%
0.19%
0.12%
$ 1,328
$ 993
$ 700
$ 465
0.51%
0.42%
0.29%
0.19%
0.76 $ 1,292
0.71 $ 1,154
0.53 $ 641
0.60%
0.57%
0.33%
0.78
0.71
0.59
0.49
0.42
0.27
5.80
3.72
1.86
0.92
0.47
0.74
0.70
0.62
0.48
0.37
6.00
3.66
1.84
0.93
0.75
0.67
0.59
0.45
5.50
4.71
1.74
120-­‐minute ramps
0.65 $ 960
0.63 $ 872
0.55 $ 697
0.50%
0.44%
0.35%
49 0.29%
0.20%
0.11%
0.07%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 786
$ 551
$ 368
$ 229
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.70
0.58
0.49
0.34
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.94
0.96
0.35
0.15
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.34
7.29
4.53
0.74 $ 1,572
0.68 $ 1,411
0.47 $ 922
0.79%
0.76%
0.38%
GOODWIN CREEK 13X13 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.45
0.18
0.04
0.01
0.00
0.00
0.00
1.50
0.55
0.23
0.07
0.04
0.00
0.47
0.35
0.14
0.04
0.00
0.00
0.00
$ 378
$ 242
$ 85
$ 24
$ 0
$ 0
$ 0
0.17%
0.11%
0.04%
0.01%
0.00%
0.00%
0.00%
0.74
0.66
0.51
0.23
0.16
0.00
$ 767
$ 519
$ 347
$ 144
$ 96
$ 0
0.36%
0.20%
0.13%
0.07%
0.04%
0.00%
1.73
0.80
0.41
0.29
0.09
1.97
0.91
0.48
0.23
0.56
0.51
0.44
0.40
0.20
$ 654
$ 473
$ 350
$ 300
$ 133
0.38%
0.26%
0.16%
0.13%
0.06%
2.23
1.72
0.57
0.53
0.44
0.36
0.24
$ 989
$ 669
$ 475
$ 296
0.38%
0.25%
0.15%
0.09%
0.53 $ 701
0.50 $ 617
0.37 $ 349
0.37%
0.31%
0.15%
3.42
2.95
2.08
5.20
2.22
1.09
0.41
0.28
0.00
$ 1,209
$ 803
$ 564
$ 330
$ 262
$ 0
0.53%
0.35%
0.24%
0.13%
0.10%
0.00%
$ 1,207
$ 960
$ 680
$ 448
$ 290
0.60%
0.39%
0.28%
0.18%
0.12%
$ 1,320
$ 995
$ 700
$ 464
0.51%
0.41%
0.29%
0.18%
0.74 $ 1,274
0.71 $ 1,152
0.53 $ 638
0.60%
0.56%
0.33%
0.76
0.69
0.59
0.41
0.35
0.00
5.80
3.72
1.86
0.92
0.47
0.73
0.69
0.61
0.46
0.33
5.99
3.65
1.84
0.93
0.74
0.67
0.59
0.45
5.49
4.71
1.74
120-­‐minute ramps
0.65 $ 954
0.62 $ 868
0.55 $ 693
0.49%
0.43%
0.35%
50 0.28%
0.18%
0.10%
0.04%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 774
$ 541
$ 316
$ 153
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.68
0.58
0.41
0.23
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.94
0.93
0.32
0.10
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.31
7.26
4.53
0.67 $ 1,501
0.63 $ 1,359
0.46 $ 918
0.52%
0.49%
0.38%
GOODWIN CREEK 20X20 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.42
0.16
0.03
0.00
0.00
0.00
0.00
1.47
0.52
0.21
0.06
0.03
0.00
0.39
0.27
0.10
0.02
0.00
0.00
0.00
$ 322
$ 191
$ 59
$ 10
$ 0
$ 0
$ 0
0.15%
0.09%
0.03%
0.00%
0.00%
0.00%
0.00%
0.68
0.55
0.40
0.20
0.14
0.00
$ 724
$ 446
$ 279
$ 122
$ 82
$ 0
0.34%
0.18%
0.11%
0.05%
0.03%
0.00%
1.71
0.78
0.38
0.16
0.07
1.95
0.89
0.46
0.22
0.50
0.44
0.35
0.24
0.15
$ 605
$ 426
$ 290
$ 175
$ 103
0.36%
0.24%
0.15%
0.09%
0.05%
2.19
1.68
0.56
0.51
0.43
0.33
0.21
$ 968
$ 656
$ 440
$ 258
0.36%
0.24%
0.14%
0.08%
0.52 $ 690
0.48 $ 595
0.36 $ 337
0.36%
0.30%
0.14%
3.41
2.94
2.07
5.33
2.07
0.95
0.41
0.27
0.00
$ 1,207
$ 767
$ 518
$ 305
$ 235
$ 0
0.51%
0.32%
0.21%
0.12%
0.09%
0.00%
$ 1,187
$ 945
$ 669
$ 442
$ 277
0.59%
0.37%
0.26%
0.17%
0.10%
$ 1,249
$ 992
$ 680
$ 447
0.49%
0.40%
0.28%
0.18%
0.70 $ 1,238
0.69 $ 1,141
0.52 $ 630
0.58%
0.55%
0.32%
0.74
0.67
0.55
0.37
0.30
0.00
5.75
3.71
1.86
0.92
0.46
0.72
0.68
0.59
0.45
0.31
5.61
3.64
1.84
0.91
0.71
0.67
0.56
0.43
5.50
4.70
1.74
120-­‐minute ramps
0.66 $ 964
0.62 $ 866
0.55 $ 693
0.49%
0.43%
0.34%
51 0.26%
0.17%
0.08%
0.02%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 749
$ 526
$ 253
$ 74
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.66
0.56
0.33
0.11
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.85
0.90
0.27
0.05
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.31
7.24
4.50
0.63 $ 1,456
0.62 $ 1,342
0.46 $ 910
0.51%
0.48%
0.37%
GOODWIN CREEK 30X30 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.38
0.12
0.01
0.00
0.00
0.00
0.00
1.44
0.48
0.15
0.05
0.01
0.00
0.32
0.20
0.07
0.00
0.00
0.00
0.00
$ 272
$ 144
$ 39
$ 0
$ 0
$ 0
$ 0
0.14%
0.07%
0.02%
0.00%
0.00%
0.00%
0.00%
0.62
0.45
0.29
0.14
0.04
0.00
$ 678
$ 379
$ 206
$ 90
$ 24
$ 0
0.32%
0.16%
0.08%
0.04%
0.01%
0.00%
1.68
0.75
0.34
0.14
0.06
1.93
0.86
0.42
0.19
0.45
0.42
0.29
0.22
0.12
$ 562
$ 403
$ 246
$ 160
$ 84
0.35%
0.22%
0.13%
0.07%
0.04%
2.15
1.64
0.53
0.48
0.42
0.27
0.17
$ 921
$ 638
$ 378
$ 212
0.35%
0.22%
0.13%
0.07%
0.51 $ 680
0.46 $ 570
0.33 $ 311
0.35%
0.29%
0.13%
3.39
2.92
2.05
5.36
1.91
0.94
0.40
0.14
0.00
$ 1,176
$ 711
$ 493
$ 282
$ 127
$ 0
0.47%
0.29%
0.19%
0.10%
0.04%
0.00%
$ 1,155
$ 909
$ 542
$ 417
$ 259
0.57%
0.35%
0.21%
0.16%
0.09%
$ 1,229
$ 974
$ 648
$ 409
0.47%
0.39%
0.27%
0.17%
0.69 $ 1,225
0.67 $ 1,114
0.50 $ 611
0.57%
0.54%
0.31%
0.70
0.62
0.52
0.34
0.17
0.00
5.78
3.68
1.37
0.91
0.45
0.68
0.63
0.51
0.42
0.29
5.58
3.62
1.82
0.91
0.69
0.65
0.52
0.38
5.45
4.67
1.72
120-­‐minute ramps
0.68 $ 974
0.62 $ 860
0.54 $ 689
0.48%
0.42%
0.33%
52 0.23%
0.15%
0.06%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 694
$ 486
$ 213
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.61
0.52
0.27
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.71
0.84
0.24
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.25
7.20
4.47
0.63 $ 1,455
0.61 $ 1,324
0.45 $ 895
0.50%
0.47%
0.36%
GOODWIN CREEK 50X50 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.30
0.08
0.00
0.00
0.00
0.00
0.00
1.34
0.34
0.10
0.02
0.00
0.00
0.27
0.18
0.03
0.00
0.00
0.00
0.00
$ 228
$ 119
$ 14
$ 0
$ 0
$ 0
$ 0
0.10%
0.04%
0.00%
0.00%
0.00%
0.00%
0.00%
0.54
0.38
0.26
0.08
0.00
0.00
$ 603
$ 308
$ 172
$ 46
$ 0
$ 0
0.28%
0.12%
0.05%
0.02%
0.00%
0.00%
1.63
0.70
0.20
0.12
0.05
1.89
0.82
0.35
0.16
0.43
0.36
0.26
0.22
0.12
$ 538
$ 357
$ 197
$ 153
$ 80
0.32%
0.20%
0.08%
0.05%
0.03%
2.10
1.58
0.47
0.46
0.38
0.22
0.12
$ 899
$ 579
$ 312
$ 161
0.33%
0.20%
0.11%
0.05%
0.50 $ 664
0.45 $ 557
0.25 $ 251
0.33%
0.27%
0.11%
2.53
2.05
2.05
4.79
1.75
0.80
0.26
0.00
0.00
$ 1,077
$ 596
$ 381
$ 180
$ 0
$ 0
0.41%
0.25%
0.15%
0.06%
0.00%
0.00%
$ 1,150
$ 784
$ 467
$ 355
$ 228
0.55%
0.31%
0.19%
0.14%
0.08%
$ 1,189
$ 921
$ 602
$ 384
0.46%
0.37%
0.25%
0.15%
0.68 $ 1,200
0.62 $ 1,062
0.44 $ 567
0.55%
0.52%
0.29%
0.65
0.49
0.38
0.21
0.00
0.00
5.82
3.20
1.36
0.90
0.45
0.67
0.54
0.40
0.33
0.24
5.50
3.57
1.80
0.90
0.66
0.59
0.47
0.34
5.35
4.59
1.70
120-­‐minute ramps
0.59 $ 792
0.54 $ 682
0.54 $ 682
0.38%
0.32%
0.32%
53 0.20%
0.12%
0.02%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 590
$ 379
$ 91
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.49
0.39
0.12
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.62
0.72
0.09
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.09
7.08
4.39
0.65 $ 1,453
0.59 $ 1,291
0.43 $ 866
0.49%
0.46%
0.35%
GOODWIN CREEK 80X80 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.24
0.06
0.00
0.00
0.00
0.00
0.00
1.25
0.28
0.07
0.01
0.00
0.00
0.27
0.16
0.02
0.00
0.00
0.00
0.00
$ 214
$ 104
$ 10
$ 0
$ 0
$ 0
$ 0
0.08%
0.03%
0.00%
0.00%
0.00%
0.00%
0.00%
0.49
0.38
0.22
0.03
0.00
0.00
$ 556
$ 291
$ 140
$ 20
$ 0
$ 0
0.24%
0.09%
0.03%
0.01%
0.00%
0.00%
1.43
0.63
0.16
0.09
0.00
1.80
0.76
0.31
0.13
0.40
0.29
0.26
0.22
0.00
$ 493
$ 296
$ 188
$ 145
$ 0
0.28%
0.17%
0.06%
0.04%
0.00%
2.00
1.49
0.42
0.44
0.26
0.17
0.09
$ 859
$ 450
$ 250
$ 119
0.30%
0.17%
0.09%
0.04%
0.48 $ 636
0.43 $ 531
0.17 $ 185
0.30%
0.25%
0.10%
2.47
2.00
0.89
4.48
1.60
0.66
0.13
0.00
0.00
$ 1,005
$ 507
$ 301
$ 99
$ 0
$ 0
0.37%
0.21%
0.11%
0.03%
0.00%
0.00%
$ 1,082
$ 731
$ 421
$ 324
$ 0
0.37%
0.29%
0.17%
0.12%
0.00%
$ 1,128
$ 719
$ 542
$ 351
0.43%
0.30%
0.23%
0.13%
0.60 $ 1,026
0.51 $ 813
0.37 $ 507
0.49%
0.42%
0.27%
0.61
0.40
0.30
0.12
0.00
0.00
5.80
3.13
1.35
0.90
0.00
0.60
0.49
0.34
0.29
0.00
5.30
2.65
1.77
0.89
0.61
0.48
0.40
0.30
4.44
3.24
1.67
120-­‐minute ramps
0.57 $ 766
0.51 $ 657
0.39 $ 407
0.36%
0.30%
0.18%
54 0.16%
0.09%
0.01%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 490
$ 317
$ 64
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.39
0.31
0.08
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.41
0.66
0.07
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
8.41
6.82
4.26
0.66 $ 1,497
0.57 $ 1,249
0.41 $ 837
0.51%
0.44%
0.33%
GOODWIN CREEK 130X130 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.13
0.04
0.00
0.00
0.00
0.00
0.00
1.06
0.16
0.05
0.01
0.00
0.00
0.25
0.11
0.00
0.00
0.00
0.00
0.00
$ 175
$ 71
$ 0
$ 0
$ 0
$ 0
$ 0
0.05%
0.02%
0.00%
0.00%
0.00%
0.00%
0.00%
0.44
0.35
0.17
0.03
0.00
0.00
$ 485
$ 240
$ 107
$ 19
$ 0
$ 0
0.21%
0.05%
0.02%
0.00%
0.00%
0.00%
1.27
0.54
0.08
0.04
0.00
1.60
0.65
0.10
0.10
0.36
0.28
0.21
0.12
0.00
$ 444
$ 277
$ 140
$ 74
$ 0
0.24%
0.14%
0.03%
0.01%
0.00%
1.78
1.31
0.33
0.40
0.21
0.08
0.08
$ 773
$ 372
$ 101
$ 101
0.26%
0.14%
0.03%
0.03%
0.44 $ 576
0.39 $ 472
0.13 $ 146
0.27%
0.21%
0.08%
2.23
1.81
0.81
3.88
1.14
0.50
0.13
0.00
0.00
$ 853
$ 379
$ 255
$ 98
$ 0
$ 0
0.34%
0.15%
0.08%
0.02%
0.00%
0.00%
$ 901
$ 570
$ 284
$ 182
$ 0
0.34%
0.24%
0.10%
0.06%
0.00%
$ 1,025
$ 624
$ 460
$ 304
0.40%
0.27%
0.20%
0.11%
0.49 $ 894
0.44 $ 724
0.31 $ 446
0.45%
0.38%
0.24%
0.51
0.31
0.26
0.12
0.00
0.00
4.76
2.53
0.86
0.43
0.00
0.50
0.37
0.24
0.18
0.00
4.86
2.48
1.69
0.85
0.55
0.39
0.31
0.25
4.09
3.01
1.59
120-­‐minute ramps
0.53 $ 707
0.47 $ 599
0.34 $ 360
0.33%
0.27%
0.15%
55 0.12%
0.06%
0.00%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 381
$ 263
$ 0
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.32
0.28
0.00
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.04
0.45
0.00
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.68
6.24
3.94
0.54 $ 1,306
0.49 $ 1,109
0.36 $ 754
0.47%
0.41%
0.31%
GOODWIN CREEK 200X200 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.07
0.03
0.00
0.00
0.00
0.00
0.00
0.70
0.09
0.03
0.01
0.00
0.00
0.19
0.10
0.00
0.00
0.00
0.00
0.00
$ 121
$ 63
$ 0
$ 0
$ 0
$ 0
$ 0
0.02%
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
0.32
0.28
0.12
0.03
0.00
0.00
$ 340
$ 178
$ 74
$ 19
$ 0
$ 0
0.15%
0.03%
0.01%
0.00%
0.00%
0.00%
0.96
0.21
0.07
0.03
0.00
1.13
0.20
0.00
0.00
0.29
0.27
0.21
0.12
0.00
$ 348
$ 205
$ 134
$ 72
$ 0
0.20%
0.06%
0.02%
0.01%
0.00%
1.08
0.64
0.00
0.31
0.10
0.00
0.00
$ 579
$ 150
$ 1
$ 1
0.19%
0.05%
0.00%
0.00%
0.31 $ 382
0.21 $ 246
0.00 $ 1
0.18%
0.12%
0.00%
1.97
1.57
0.68
3.06
0.66
0.33
0.11
0.00
0.00
$ 673
$ 293
$ 205
$ 94
$ 0
$ 0
0.29%
0.09%
0.05%
0.02%
0.00%
0.00%
$ 720
$ 370
$ 265
$ 171
$ 0
0.30%
0.16%
0.09%
0.05%
0.00%
$ 792
$ 369
$ 0
$ 0
0.35%
0.18%
0.00%
0.00%
0.42 $ 757
0.36 $ 606
0.00 $ 0
0.41%
0.34%
0.00%
0.40
0.28
0.23
0.12
0.00
0.00
3.83
1.46
0.74
0.37
0.00
0.40
0.26
0.23
0.17
0.00
3.74
1.44
0.00
0.00
0.43
0.24
0.00
0.00
3.46
2.55
0.00
120-­‐minute ramps
0.50 $ 645
0.39 $ 504
0.26 $ 284
0.30%
0.24%
0.13%
56 0.07%
0.04%
0.00%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 299
$ 223
$ 0
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.29
0.26
0.00
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.61
0.31
0.00
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.52
5.29
3.32
0.46 $ 1,107
0.41 $ 930
0.32 $ 658
0.44%
0.37%
0.28%
KALAEOLA Single Point
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.73
0.37
0.16
0.08
0.05
0.03
0.02
1.69
0.70
0.34
0.18
0.12
0.09
0.93
0.96
0.99
0.89
0.88
0.80
0.73
$ 625
$ 560
$ 501
$ 421
$ 388
$ 343
$ 295
0.65%
0.59%
0.50%
0.42%
0.36%
0.31%
0.23%
0.73
0.73
0.75
0.70
0.64
0.61
$ 636
$ 513
$ 450
$ 380
$ 332
$ 306
0.63%
0.53%
0.46%
0.38%
0.33%
0.29%
2.06
0.85
0.50
0.32
0.22
1.94
0.80
0.61
0.40
0.65
0.63
0.60
0.57
0.50
$ 623
$ 478
$ 407
$ 359
$ 300
0.57%
0.45%
0.39%
0.34%
0.29%
1.83
1.21
0.84
0.59
0.51
0.46
0.45
$ 575
$ 402
$ 345
$ 312
0.49%
0.37%
0.34%
0.30%
0.54 $ 530
0.41 $ 387
0.43 $ 355
0.41%
0.34%
0.30%
3.01
2.38
1.81
4.12
2.24
1.37
0.69
0.43
0.29
$ 954
$ 751
$ 637
$ 549
$ 484
$ 423
0.73%
0.52%
0.50%
0.44%
0.40%
0.36%
$ 853
$ 785
$ 571
$ 512
$ 444
0.67%
0.44%
0.41%
0.38%
0.34%
$ 846
$ 646
$ 563
$ 471
0.60%
0.37%
0.35%
0.32%
0.62 $ 769
0.64 $ 733
0.58 $ 618
0.48%
0.30%
0.29%
0.87
0.82
0.79
0.81
0.78
0.72
4.37
3.26
1.71
1.15
0.80
0.70
0.73
0.62
0.62
0.58
4.32
2.43
1.96
1.43
0.71
0.63
0.57
0.51
4.08
3.51
2.54
120-­‐minute ramps
0.61 $ 675
0.48 $ 532
0.41 $ 440
0.42%
0.36%
0.32%
57 0.64%
0.62%
0.56%
0.51%
0.45%
0.40%
0.32%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 825
$ 716
$ 613
$ 557
$ 479
$ 434
$ 360
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.91
0.91
0.96
0.99
0.93
0.88
0.78
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
2.38
1.43
0.61
0.32
0.17
0.12
0.06
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
5.13
4.57
3.94
0.55 $ 793
0.56 $ 757
0.56 $ 708
0.60%
0.42%
0.25%
KALAEOLA 1X1 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.50
0.26
0.09
0.05
0.02
0.02
0.01
1.28
0.55
0.30
0.13
0.09
0.06
0.79
0.77
0.75
0.63
0.46
0.42
0.34
$ 506
$ 438
$ 366
$ 288
$ 200
$ 178
$ 140
0.35%
0.30%
0.24%
0.16%
0.10%
0.08%
0.07%
1.05
0.98
0.89
0.76
0.71
0.64
$ 781
$ 618
$ 505
$ 383
$ 348
$ 302
0.48%
0.38%
0.33%
0.26%
0.23%
0.18%
1.46
0.78
0.43
0.32
0.21
1.58
0.91
0.73
0.28
0.64
0.63
0.61
0.53
0.42
$ 555
$ 466
$ 399
$ 337
$ 257
0.46%
0.37%
0.30%
0.28%
0.24%
2.07
1.00
0.53
0.63
0.59
0.62
0.44
$ 843
$ 699
$ 685
$ 426
0.42%
0.34%
0.31%
0.20%
0.56 $ 575
0.43 $ 385
0.35 $ 277
0.35%
0.25%
0.19%
2.28
1.81
0.97
#N/A
2.03
1.12
0.52
0.40
0.27
#N/A
$ 739
$ 592
$ 423
$ 365
$ 295
#N/A
0.45%
0.38%
0.30%
0.28%
0.25%
$ 884
$ 713
$ 553
$ 503
$ 405
0.54%
0.42%
0.35%
0.32%
0.28%
$ 923
$ 740
$ 665
$ 421
0.53%
0.39%
0.37%
0.25%
0.69 $ 846
0.66 $ 786
0.49 $ 487
0.53%
0.42%
0.30%
#N/A
0.86
0.78
0.63
0.56
0.48
5.38
3.04
1.72
1.32
0.90
0.72
0.70
0.62
0.60
0.51
5.24
3.09
2.46
0.91
0.71
0.68
0.64
0.50
4.37
3.96
1.74
120-­‐minute ramps
0.59 $ 598
0.46 $ 472
0.34 $ 314
0.35%
0.30%
0.21%
58 0.34%
0.30%
0.25%
0.21%
0.15%
0.13%
0.10%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 780
$ 627
$ 496
$ 397
$ 295
$ 294
$ 250
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.92
0.84
0.79
0.70
0.57
0.59
0.52
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.96
1.05
0.46
0.23
0.11
0.08
0.06
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.65
6.81
3.88
0.54 $ 971
0.55 $ 926
0.45 $ 640
0.71%
0.49%
0.27%
KALAEOLA 2X2 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.46
0.22
0.08
0.04
0.02
0.02
0.00
1.21
0.53
0.26
0.12
0.09
0.03
0.74
0.71
0.70
0.57
0.41
0.33
0.13
$ 473
$ 401
$ 340
$ 259
$ 182
$ 144
$ 55
0.31%
0.26%
0.20%
0.11%
0.07%
0.05%
0.03%
0.98
0.91
0.84
0.66
0.61
0.41
$ 732
$ 577
$ 469
$ 339
$ 303
$ 186
0.45%
0.35%
0.29%
0.23%
0.20%
0.09%
1.41
0.76
0.40
0.19
0.19
1.52
0.88
0.71
0.27
0.62
0.61
0.56
0.38
0.38
$ 534
$ 451
$ 373
$ 235
$ 235
0.44%
0.36%
0.28%
0.22%
0.22%
2.02
0.98
0.54
0.61
0.58
0.60
0.39
$ 816
$ 681
$ 662
$ 388
0.40%
0.32%
0.30%
0.19%
0.58 $ 578
0.43 $ 379
0.34 $ 274
0.35%
0.24%
0.18%
2.15
1.70
0.94
4.64
1.93
1.00
0.52
0.39
0.14
$ 938
$ 695
$ 539
$ 405
$ 354
$ 201
0.55%
0.42%
0.34%
0.28%
0.25%
0.16%
$ 864
$ 694
$ 546
$ 401
$ 401
0.53%
0.41%
0.33%
0.26%
0.26%
$ 902
$ 727
$ 552
$ 414
0.52%
0.38%
0.32%
0.24%
0.69 $ 847
0.59 $ 667
0.49 $ 489
0.52%
0.38%
0.30%
0.83
0.81
0.72
0.60
0.54
0.35
5.52
3.00
1.72
0.89
0.89
0.68
0.68
0.60
0.50
0.50
5.21
3.07
1.74
0.91
0.69
0.66
0.57
0.49
4.39
3.02
1.75
120-­‐minute ramps
0.57 $ 576
0.45 $ 454
0.33 $ 300
0.35%
0.29%
0.21%
59 0.35%
0.29%
0.23%
0.18%
0.12%
0.10%
0.04%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 748
$ 605
$ 447
$ 361
$ 276
$ 249
$ 133
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.88
0.82
0.71
0.64
0.53
0.49
0.28
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.83
0.98
0.42
0.19
0.10
0.08
0.03
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.59
6.76
3.83
0.52 $ 954
0.53 $ 911
0.41 $ 610
0.70%
0.49%
0.27%
KALAEOLA 3X3 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.46
0.23
0.09
0.04
0.02
0.01
0.00
1.20
0.54
0.25
0.12
0.09
0.03
0.76
0.71
0.64
0.52
0.32
0.19
0.10
$ 484
$ 402
$ 314
$ 233
$ 144
$ 80
$ 42
0.30%
0.25%
0.18%
0.10%
0.05%
0.03%
0.02%
1.01
0.93
0.84
0.64
0.59
0.42
$ 746
$ 587
$ 471
$ 328
$ 294
$ 189
0.44%
0.34%
0.27%
0.22%
0.19%
0.08%
1.43
0.76
0.41
0.20
0.20
1.58
0.89
0.71
0.27
0.61
0.60
0.57
0.39
0.39
$ 529
$ 450
$ 379
$ 240
$ 240
0.44%
0.35%
0.28%
0.21%
0.21%
2.06
0.98
0.53
0.61
0.58
0.61
0.42
$ 822
$ 685
$ 671
$ 407
0.40%
0.32%
0.29%
0.19%
0.56 $ 575
0.42 $ 373
0.34 $ 273
0.34%
0.24%
0.17%
2.23
1.77
0.95
4.66
1.92
1.00
0.52
0.39
0.14
$ 948
$ 703
$ 560
$ 420
$ 361
$ 207
0.55%
0.42%
0.33%
0.27%
0.24%
0.15%
$ 870
$ 694
$ 539
$ 482
$ 401
0.52%
0.40%
0.33%
0.30%
0.26%
$ 916
$ 734
$ 656
$ 419
0.51%
0.38%
0.35%
0.24%
0.69 $ 850
0.59 $ 667
0.49 $ 486
0.52%
0.37%
0.29%
0.84
0.82
0.75
0.63
0.56
0.36
5.42
3.03
1.72
1.32
0.89
0.69
0.67
0.59
0.56
0.50
5.26
3.08
2.45
0.91
0.70
0.67
0.63
0.50
4.43
3.02
1.73
120-­‐minute ramps
0.57 $ 579
0.45 $ 457
0.33 $ 303
0.34%
0.29%
0.21%
60 0.35%
0.29%
0.22%
0.17%
0.11%
0.07%
0.04%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 755
$ 616
$ 430
$ 350
$ 278
$ 200
$ 128
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.90
0.84
0.68
0.62
0.54
0.41
0.27
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.79
1.00
0.42
0.19
0.10
0.05
0.03
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.64
6.80
3.85
0.52 $ 957
0.53 $ 914
0.43 $ 627
0.69%
0.48%
0.26%
KALAEOLA 5X5 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.42
0.19
0.07
0.03
0.01
0.00
0.00
1.16
0.51
0.24
0.11
0.05
0.03
0.71
0.65
0.51
0.40
0.19
0.08
0.00
$ 446
$ 363
$ 248
$ 182
$ 82
$ 33
$ 0
0.26%
0.20%
0.13%
0.07%
0.03%
0.01%
0.00%
0.94
0.87
0.80
0.59
0.44
0.34
$ 700
$ 549
$ 446
$ 303
$ 213
$ 153
0.41%
0.30%
0.24%
0.18%
0.11%
0.05%
1.34
0.74
0.30
0.19
0.10
1.54
0.88
0.50
0.25
0.60
0.58
0.47
0.37
0.25
$ 519
$ 434
$ 304
$ 231
$ 145
0.40%
0.32%
0.22%
0.18%
0.13%
1.67
0.97
0.53
0.59
0.56
0.56
0.40
$ 798
$ 667
$ 582
$ 387
0.38%
0.30%
0.23%
0.17%
0.51 $ 500
0.41 $ 363
0.33 $ 267
0.30%
0.22%
0.16%
2.13
1.69
0.91
4.57
1.87
1.01
0.52
0.26
0.13
$ 887
$ 663
$ 533
$ 396
$ 265
$ 185
0.54%
0.39%
0.31%
0.24%
0.18%
0.12%
$ 843
$ 658
$ 466
$ 396
$ 265
0.50%
0.37%
0.27%
0.23%
0.17%
$ 903
$ 699
$ 534
$ 412
0.50%
0.36%
0.29%
0.22%
0.69 $ 856
0.59 $ 662
0.49 $ 484
0.51%
0.36%
0.27%
0.76
0.76
0.70
0.58
0.42
0.32
5.56
3.04
1.33
0.90
0.46
0.65
0.62
0.54
0.50
0.36
5.12
3.07
1.74
0.91
0.69
0.62
0.55
0.49
4.48
3.00
1.72
120-­‐minute ramps
0.54 $ 555
0.43 $ 438
0.33 $ 304
0.33%
0.28%
0.20%
61 0.32%
0.25%
0.18%
0.14%
0.07%
0.03%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 703
$ 562
$ 371
$ 282
$ 190
$ 85
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.83
0.76
0.58
0.48
0.36
0.17
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.75
0.93
0.38
0.19
0.08
0.03
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.58
6.75
3.83
0.52 $ 953
0.53 $ 909
0.43 $ 617
0.69%
0.48%
0.25%
KALAEOLA 8X8 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.38
0.16
0.05
0.01
0.00
0.00
0.00
1.13
0.46
0.19
0.10
0.04
0.02
0.56
0.50
0.31
0.11
0.00
0.00
0.00
$ 363
$ 280
$ 154
$ 49
$ 0
$ 0
$ 0
0.21%
0.16%
0.09%
0.02%
0.00%
0.00%
0.00%
0.85
0.77
0.63
0.46
0.29
0.20
$ 650
$ 489
$ 351
$ 243
$ 146
$ 92
0.36%
0.25%
0.18%
0.14%
0.08%
0.04%
1.28
0.64
0.27
0.17
0.09
1.61
0.86
0.49
0.24
0.57
0.56
0.44
0.34
0.23
$ 495
$ 408
$ 281
$ 207
$ 134
0.36%
0.27%
0.19%
0.15%
0.11%
1.65
0.95
0.52
0.59
0.54
0.52
0.37
$ 811
$ 643
$ 545
$ 360
0.36%
0.27%
0.20%
0.14%
0.50 $ 494
0.39 $ 351
0.31 $ 253
0.28%
0.21%
0.15%
2.06
1.63
0.85
4.57
1.67
0.89
0.52
0.26
0.13
$ 824
$ 552
$ 430
$ 335
$ 246
$ 151
0.50%
0.33%
0.25%
0.20%
0.15%
0.09%
$ 810
$ 621
$ 446
$ 379
$ 243
0.47%
0.33%
0.24%
0.20%
0.14%
$ 885
$ 674
$ 518
$ 393
0.48%
0.34%
0.27%
0.20%
0.67 $ 845
0.58 $ 657
0.48 $ 480
0.39%
0.34%
0.26%
0.68
0.61
0.56
0.48
0.38
0.25
5.50
2.69
1.32
0.89
0.45
0.61
0.60
0.51
0.47
0.32
5.15
3.03
1.72
0.90
0.66
0.59
0.52
0.46
4.58
2.96
1.70
120-­‐minute ramps
0.56 $ 557
0.44 $ 439
0.35 $ 305
0.31%
0.27%
0.18%
62 0.27%
0.21%
0.14%
0.07%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 572
$ 452
$ 321
$ 141
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.65
0.59
0.49
0.24
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.58
0.81
0.33
0.10
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.50
6.68
3.77
0.52 $ 947
0.53 $ 904
0.42 $ 604
0.67%
0.46%
0.24%
KALAEOLA 13X13 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.33
0.13
0.03
0.00
0.00
0.00
0.00
1.07
0.40
0.17
0.06
0.03
0.00
0.47
0.33
0.17
0.02
0.00
0.00
0.00
$ 308
$ 193
$ 87
$ 10
$ 0
$ 0
$ 0
0.17%
0.12%
0.05%
0.01%
0.00%
0.00%
0.00%
0.75
0.67
0.45
0.27
0.21
0.00
$ 579
$ 422
$ 262
$ 142
$ 107
$ 0
0.31%
0.20%
0.15%
0.09%
0.06%
0.00%
1.26
0.69
0.25
0.16
0.07
1.45
0.82
0.45
0.22
0.53
0.51
0.40
0.32
0.20
$ 467
$ 384
$ 259
$ 197
$ 118
0.33%
0.25%
0.15%
0.12%
0.08%
1.61
0.91
0.48
0.53
0.50
0.48
0.34
$ 730
$ 597
$ 502
$ 332
0.32%
0.24%
0.18%
0.12%
0.49 $ 483
0.35 $ 320
0.26 $ 220
0.26%
0.19%
0.13%
1.99
1.58
0.80
3.74
1.63
0.87
0.38
0.26
0.00
$ 705
$ 516
$ 401
$ 269
$ 209
$ 0
0.41%
0.29%
0.22%
0.15%
0.12%
0.00%
$ 793
$ 590
$ 422
$ 341
$ 226
0.44%
0.29%
0.21%
0.18%
0.12%
$ 870
$ 657
$ 494
$ 353
0.46%
0.32%
0.25%
0.18%
0.63 $ 751
0.57 $ 634
0.47 $ 467
0.36%
0.32%
0.24%
0.60
0.57
0.51
0.39
0.32
0.00
5.28
2.60
1.28
0.87
0.44
0.60
0.56
0.48
0.41
0.30
5.10
2.93
1.65
0.87
0.66
0.58
0.50
0.40
3.74
2.84
1.62
120-­‐minute ramps
0.53 $ 537
0.42 $ 423
0.34 $ 297
0.30%
0.25%
0.17%
63 0.23%
0.17%
0.10%
0.01%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 506
$ 394
$ 239
$ 33
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.56
0.51
0.37
0.05
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.45
0.74
0.25
0.02
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.29
6.48
3.65
0.51 $ 921
0.52 $ 879
0.42 $ 598
0.66%
0.45%
0.22%
KALAEOLA 20X20 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.25
0.09
0.01
0.00
0.00
0.00
0.00
0.94
0.32
0.11
0.03
0.00
0.00
0.39
0.24
0.08
0.03
0.00
0.00
0.00
$ 251
$ 137
$ 41
$ 12
$ 0
$ 0
$ 0
0.13%
0.09%
0.02%
0.00%
0.00%
0.00%
0.00%
0.65
0.56
0.33
0.15
0.00
0.00
$ 508
$ 351
$ 188
$ 76
$ 0
$ 0
0.26%
0.16%
0.10%
0.04%
0.00%
0.00%
1.12
0.62
0.21
0.13
0.06
1.21
0.57
0.38
0.18
0.47
0.43
0.34
0.25
0.15
$ 409
$ 334
$ 218
$ 156
$ 87
0.28%
0.21%
0.12%
0.09%
0.06%
1.20
0.84
0.44
0.46
0.42
0.39
0.28
$ 626
$ 476
$ 415
$ 268
0.27%
0.18%
0.15%
0.10%
0.37 $ 360
0.32 $ 294
0.23 $ 190
0.21%
0.17%
0.11%
1.93
1.53
0.77
3.44
1.44
0.70
0.24
0.00
0.00
$ 667
$ 475
$ 317
$ 166
$ 0
$ 0
0.36%
0.24%
0.17%
0.09%
0.00%
0.00%
$ 782
$ 534
$ 379
$ 303
$ 184
0.41%
0.25%
0.18%
0.15%
0.10%
$ 843
$ 577
$ 477
$ 310
0.44%
0.26%
0.22%
0.15%
0.57 $ 688
0.54 $ 604
0.45 $ 445
0.34%
0.30%
0.22%
0.57
0.53
0.40
0.24
0.00
0.00
5.24
2.19
1.20
0.81
0.41
0.59
0.53
0.42
0.36
0.23
5.03
2.18
1.56
0.81
0.63
0.55
0.49
0.35
3.50
2.66
1.53
120-­‐minute ramps
0.53 $ 528
0.42 $ 416
0.33 $ 287
0.27%
0.23%
0.15%
64 0.20%
0.14%
0.07%
0.01%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 467
$ 323
$ 147
$ 33
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.52
0.41
0.22
0.06
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.31
0.65
0.17
0.02
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.17
6.38
3.43
0.49 $ 902
0.50 $ 861
0.40 $ 575
0.63%
0.44%
0.21%
KALAEOLA 30X30 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.18
0.05
0.01
0.00
0.00
0.00
0.00
0.80
0.23
0.06
0.02
0.00
0.00
0.27
0.18
0.06
0.03
0.00
0.00
0.00
$ 178
$ 101
$ 30
$ 13
$ 0
$ 0
$ 0
0.10%
0.05%
0.01%
0.00%
0.00%
0.00%
0.00%
0.47
0.38
0.23
0.14
0.00
0.00
$ 386
$ 242
$ 124
$ 69
$ 0
$ 0
0.22%
0.12%
0.06%
0.03%
0.00%
0.00%
0.99
0.47
0.17
0.04
0.00
1.14
0.47
0.30
0.15
0.37
0.32
0.25
0.13
0.00
$ 334
$ 250
$ 162
$ 77
$ 0
0.24%
0.16%
0.09%
0.04%
0.00%
1.14
0.74
0.37
0.37
0.31
0.28
0.21
$ 530
$ 361
$ 305
$ 206
0.24%
0.15%
0.12%
0.07%
0.35 $ 344
0.31 $ 276
0.20 $ 169
0.19%
0.15%
0.10%
1.90
1.50
0.74
3.30
1.34
0.56
0.23
0.00
0.00
$ 652
$ 442
$ 253
$ 151
$ 0
$ 0
0.31%
0.21%
0.12%
0.07%
0.00%
0.00%
$ 752
$ 498
$ 340
$ 165
$ 0
0.38%
0.22%
0.16%
0.08%
0.00%
$ 800
$ 534
$ 437
$ 274
0.42%
0.24%
0.20%
0.13%
0.53 $ 644
0.51 $ 564
0.42 $ 409
0.33%
0.28%
0.20%
0.57
0.49
0.32
0.21
0.00
0.00
5.19
2.03
1.10
0.38
0.00
0.56
0.49
0.37
0.21
0.00
4.91
2.01
1.40
0.74
0.59
0.51
0.45
0.30
3.32
2.47
1.39
120-­‐minute ramps
0.48 $ 489
0.38 $ 385
0.31 $ 272
0.25%
0.22%
0.14%
65 0.17%
0.09%
0.05%
0.01%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 435
$ 251
$ 142
$ 38
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.49
0.33
0.21
0.07
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.23
0.46
0.17
0.02
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
7.08
6.30
3.36
0.46 $ 879
0.47 $ 839
0.39 $ 561
0.62%
0.43%
0.20%
KALAEOLA 50X50 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.15
0.03
0.00
0.00
0.00
0.00
0.00
0.65
0.20
0.04
0.01
0.00
0.00
0.20
0.10
0.03
0.03
0.00
0.00
0.00
$ 132
$ 58
$ 14
$ 11
$ 0
$ 0
$ 0
0.07%
0.03%
0.00%
0.00%
0.00%
0.00%
0.00%
0.42
0.29
0.12
0.03
0.00
0.00
$ 336
$ 190
$ 65
$ 18
$ 0
$ 0
0.16%
0.08%
0.03%
0.01%
0.00%
0.00%
1.30
0.32
0.09
0.04
0.00
0.90
0.39
0.26
0.13
0.40
0.27
0.13
0.08
0.00
$ 387
$ 200
$ 87
$ 47
$ 0
0.23%
0.11%
0.05%
0.03%
0.00%
1.11
0.68
0.31
0.32
0.27
0.23
0.13
$ 444
$ 312
$ 253
$ 143
0.19%
0.12%
0.09%
0.05%
0.35 $ 340
0.25 $ 234
0.17 $ 140
0.17%
0.13%
0.07%
1.83
1.45
0.73
3.02
1.19
0.31
0.10
0.00
0.00
$ 588
$ 348
$ 179
$ 82
$ 0
$ 0
0.26%
0.16%
0.06%
0.03%
0.00%
0.00%
$ 615
$ 442
$ 228
$ 148
$ 0
0.26%
0.19%
0.10%
0.06%
0.00%
$ 638
$ 475
$ 378
$ 230
0.28%
0.21%
0.16%
0.10%
0.53 $ 654
0.45 $ 513
0.36 $ 356
0.34%
0.26%
0.17%
0.50
0.37
0.24
0.12
0.00
0.00
3.84
2.00
0.70
0.35
0.00
0.49
0.42
0.26
0.18
0.00
3.35
1.98
1.37
0.69
0.51
0.43
0.37
0.24
3.46
2.32
1.26
120-­‐minute ramps
0.42 $ 447
0.33 $ 353
0.25 $ 234
0.23%
0.19%
0.12%
66 0.13%
0.06%
0.01%
0.01%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 348
$ 206
$ 41
$ 31
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.37
0.28
0.07
0.05
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
1.09
0.33
0.04
0.02
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
6.74
6.00
3.30
0.47 $ 856
0.48 $ 817
0.37 $ 538
0.59%
0.41%
0.18%
KALAEOLA 80X80 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.11
0.03
0.00
0.00
0.00
0.00
0.00
0.58
0.13
0.03
0.01
0.00
0.00
0.17
0.10
0.03
0.03
0.00
0.00
0.00
$ 107
$ 55
$ 14
$ 11
$ 0
$ 0
$ 0
0.03%
0.02%
0.00%
0.00%
0.00%
0.00%
0.00%
0.44
0.24
0.11
0.03
0.00
0.00
$ 333
$ 148
$ 63
$ 17
$ 0
$ 0
0.12%
0.04%
0.02%
0.01%
0.00%
0.00%
1.23
0.29
0.08
0.03
0.00
0.88
0.36
0.13
0.13
0.38
0.29
0.14
0.07
0.00
$ 365
$ 204
$ 87
$ 44
$ 0
0.20%
0.08%
0.03%
0.02%
0.00%
1.05
0.64
0.28
0.33
0.29
0.15
0.15
$ 453
$ 321
$ 151
$ 151
0.15%
0.09%
0.03%
0.03%
0.33 $ 320
0.22 $ 210
0.16 $ 133
0.14%
0.10%
0.06%
1.78
1.41
0.73
3.01
0.97
0.39
0.10
0.00
0.00
$ 562
$ 313
$ 207
$ 81
$ 0
$ 0
0.24%
0.11%
0.06%
0.02%
0.00%
0.00%
$ 578
$ 397
$ 231
$ 148
$ 0
0.25%
0.16%
0.07%
0.04%
0.00%
$ 606
$ 438
$ 232
$ 232
0.27%
0.18%
0.08%
0.08%
0.51 $ 638
0.43 $ 490
0.30 $ 315
0.33%
0.24%
0.15%
0.47
0.35
0.27
0.12
0.00
0.00
3.68
1.92
0.67
0.34
0.00
0.45
0.36
0.26
0.19
0.00
3.21
1.93
0.68
0.68
0.49
0.39
0.25
0.25
3.47
2.30
1.24
120-­‐minute ramps
0.43 $ 449
0.34 $ 354
0.18 $ 184
0.20%
0.17%
0.10%
67 0.09%
0.04%
0.01%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 304
$ 204
$ 40
$ 31
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.34
0.28
0.07
0.05
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.83
0.31
0.03
0.02
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
4.93
4.39
3.13
0.38 $ 649
0.39 $ 619
0.34 $ 500
0.32%
0.22%
0.16%
KALAEOLA 130X130 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.06
0.02
0.00
0.00
0.00
0.00
0.00
0.43
0.07
0.03
0.01
0.00
0.00
0.12
0.09
0.01
0.00
0.00
0.00
0.00
$ 76
$ 47
$ 6
$ 0
$ 0
$ 0
$ 0
0.02%
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
0.38
0.17
0.10
0.03
0.00
0.00
$ 279
$ 99
$ 57
$ 16
$ 0
$ 0
0.09%
0.02%
0.01%
0.00%
0.00%
0.00%
0.57
0.15
0.07
0.03
0.00
0.60
0.21
0.11
0.11
0.29
0.20
0.12
0.06
0.00
$ 242
$ 136
$ 76
$ 39
$ 0
0.11%
0.04%
0.02%
0.01%
0.00%
0.91
0.54
0.00
0.28
0.21
0.12
0.12
$ 360
$ 223
$ 129
$ 129
0.11%
0.05%
0.02%
0.02%
0.25 $ 255
0.20 $ 189
0.00 $ 0
0.12%
0.08%
0.00%
1.53
1.21
0.62
2.34
0.53
0.27
0.09
0.00
0.00
$ 449
$ 223
$ 158
$ 73
$ 0
$ 0
0.21%
0.06%
0.03%
0.01%
0.00%
0.00%
$ 479
$ 284
$ 204
$ 133
$ 0
0.22%
0.11%
0.06%
0.03%
0.00%
$ 508
$ 295
$ 207
$ 207
0.24%
0.12%
0.07%
0.07%
0.44 $ 554
0.36 $ 438
0.00 $ 0
0.27%
0.21%
0.00%
0.38
0.27
0.22
0.11
0.00
0.00
3.07
1.22
0.61
0.31
0.00
0.38
0.28
0.23
0.17
0.00
2.86
1.24
0.62
0.62
0.39
0.27
0.22
0.22
3.04
2.25
0.00
120-­‐minute ramps
0.38 $ 387
0.30 $ 305
0.15 $ 155
0.17%
0.15%
0.08%
68 0.05%
0.03%
0.00%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 230
$ 173
$ 17
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.28
0.24
0.03
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.50
0.25
0.02
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
4.58
4.08
2.80
0.34 $ 597
0.35 $ 570
0.31 $ 445
0.29%
0.20%
0.14%
KALAEOLA 200X200 km
IDEAL FORECAST
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
Buffer losses
One-­‐minute ramps
Maximum acceptable ramp (% installed PV capacity)
0.5%
1%
3%
5%
10%
15%
25%
0.05
0.02
0.00
0.00
0.00
0.00
0.00
0.28
0.07
0.03
0.00
0.00
0.00
0.11
0.07
0.00
0.00
0.00
0.00
0.00
$ 66
$ 38
$ 0
$ 0
$ 0
$ 0
$ 0
0.01%
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
0.32
0.15
0.09
0.00
0.00
0.00
$ 222
$ 90
$ 52
$ 0
$ 0
$ 0
0.06%
0.02%
0.01%
0.00%
0.00%
0.00%
0.39
0.10
0.03
0.00
0.00
0.48
0.10
0.10
0.00
0.25
0.15
0.06
0.00
0.00
$ 198
$ 96
$ 35
$ 0
$ 0
0.09%
0.02%
0.01%
0.00%
0.00%
0.43
0.20
0.00
0.25
0.11
0.11
0.00
$ 310
$ 114
$ 114
$ 1
0.09%
0.02%
0.02%
0.00%
0.18 $ 164
0.14 $ 110
0.00 $ 0
0.07%
0.03%
0.00%
1.22
0.97
0.46
2.00
0.47
0.24
0.00
0.00
0.00
$ 379
$ 198
$ 141
$ 0
$ 0
$ 0
0.20%
0.05%
0.03%
0.00%
0.00%
0.00%
$ 409
$ 217
$ 118
$ 0
$ 0
0.21%
0.07%
0.03%
0.00%
0.00%
$ 455
$ 179
$ 179
$ 0
0.23%
0.06%
0.06%
0.00%
0.30 $ 373
0.19 $ 214
0.00 $ 0
0.20%
0.11%
0.00%
0.32
0.24
0.19
0.00
0.00
0.00
2.69
0.80
0.27
0.00
0.00
0.32
0.23
0.15
0.00
0.00
2.52
0.54
0.54
0.00
0.35
0.19
0.19
0.00
1.93
1.00
0.00
120-­‐minute ramps
0.26 $ 287
0.21 $ 226
0.12 $ 124
0.16%
0.13%
0.07%
69 0.04%
0.02%
0.00%
0.00%
0.00%
0.00%
0.00%
60-­‐minute ramps
120-­‐minute ramps
10%
15%
25%
$ 197
$ 145
$ 0
$ 0
$ 0
$ 0
$ 0
30-­‐minute ramps
60-­‐minute ramps
10%
15%
25%
0.25
0.21
0.00
0.00
0.00
0.00
0.00
15-­‐minute ramps
30-­‐minute ramps
5%
10%
15%
25%
0.41
0.20
0.00
0.00
0.00
0.00
0.00
5-­‐minute ramps
15-­‐minute ramps
3%
5%
10%
15%
25%
Buffer losses
One-­‐minute ramps
5-­‐minute ramps
1%
3%
5%
10%
15%
25%
NO FORECASTS
Buffer Buffer energy power Buffer capacity capacity cost
(kWh)
(kW)
2.59
2.30
2.30
0.23 $ 371
0.24 $ 354
0.24 $ 354
0.20%
0.14%
0.14%