Oregon Wave Energy Trust
Utility Market Initiative
Task 2.2: Wave Resource
Assessment
www.oregonwave.org www.peventuresllc.com The Utility Market Initiative was prepared by Pacific Energy Ventures on behalf of the Oregon Wave Energy Trust. December 2009
This work was funded by the Oregon Wave Energy Trust (OWET). OWET was funded in part with Oregon State Lottery Funds administered by the Oregon Business Development Department. It is one of six Oregon Innovation Council initiatives supporting job creation and long term economic growth. This Utility Market Initiative was prepared by Pacific Energy Ventures on behalf of the Oregon Wave Energy Trust. For information about this project, please contact Justin Klure at Pacific Energy Ventures: Phone: (503) 475‐2999 Email: jklure@peventuresllc.com About Oregon Wave Energy Trust The Oregon Wave Energy Trust – (OWET) ‐ with members from fishing and environmental groups, industry and government ‐ is a nonprofit public‐private partnership funded by the Oregon Innovation Council in 2007. Its mission is to serve as a connector for all stakeholders involved in wave energy project development ‐ from research and development to early stage community engagement and final deployment and energy generation ‐ positioning Oregon as the North America leader in this nascent industry and delivering its full economic and environmental potential for the state. OWET's goal is to have ocean wave energy producing 2 megawatts of power ‐ enough to power about 800 homes ‐ by 2010 and 500 megawatts of power by 2025. Wave Resource Assessment
Wave Energy Resource Potential
In an effort to understand the persistence and variability of the wave resource, analysis was conducted
on 5 years of hourly data collected from NOAA buoy 46229 off the coast of Reedsport, Oregon. This
buoy was selected because of the quality of the data set. Although this buoy is in a water depth of 187
meters which is greater than expected for deployment of wave energy conversion devices, this data
provides a good introduction to the potential variability of the resource.
Ultimately, potential purchasers of the wave energy resource will want to see resource estimates
conveyed in kWh our MWhs. However, at this point there is not sufficient information about the
technologies to translate the resource potential into generation. Therefore, the hourly data from the
buoy is used to develop an estimate of the resource potential. Key caveats about the following
information.


The data is not a representation of power production, simply resource potential. Wave energy
technologies will not be able to extract the full amount of power represented.
Some peaks shown in the graphs will be softened because the technology will not be designed
to capture the peak power.
Figure 1
Approach to Estimating
Resource Potential
Resource potential analysis relies on
estimates of the energy in the wave
resource and of how much energy the
technology can extract. As stated above,
there is not sufficient publicly available
information at this time to determine the
amount of energy that the technology
can extract, but the information is
assumed to be privately held. However,
there are methods for estimating the
energy of the wave resource.
As described in Figure 1, the energy of the wave resource is conveyed through a concept called power
flux. Wave power density is defined as the flux of energy across a vertical plane intersecting the sea
surface and is calculated using the following formula 1.
Power Flux = .42(Wave Height^2)(Wave Period)
1
The 0.42 multiplier in the above equation is exact for any sea state that is well represented by a two-parameter Bretschneider spectrum, but
it could range from 0.3 to 0.5, depending on the relative amounts of energy in sea and swell components and the exact shape of the wave
spectrum.
Utility Market Initiative
Page 1
The energy content of waves is function of wave height and wave period.
•
Wave height is a measure of the amplitude of oscillation of water particles, in the vertical
direction with respect to a fixed point. The significant wave height is a commonly used term and
is approximately equal to the average height of the highest one-third of the waves.
•
Wave period is the time that elapses between successive peaks or troughs of a wave passing a
fixed point. Like wave heights, waves exhibit a range of periods. The zero up-crossing period is
one such commonly used term and is the average time interval
Figure 2.
Overview of Analysis in Subsequent Graphs
Annual Duration Curve - Arranges all hourly resource potential data from highest to lowest and assigns
a probability of occurrence.
Monthly Duration Curve - Arranges all hourly resource potential data gathered for that month from
highest to lowest and assigns a probability of occurrence.
Monthly Total Energy - Conveys the average resource potential for each month of the year and includes
the highest and lowest recorded resource potential by month.
Daily Energy - Conveys the average resource potential for each day of the year and includes the highest
and lowest recorded hour for each day.
Sample 24-hour periods - Hourly resource potential for sample days of the year. Includes a winter
storm, spring storm, summer storm and a typical summer day.
Utility Market Initiative
Page 2
This curve indicates the cumulative probability of achieving a certain level of resource potential.
•
•
•
100% of the time the resource potential is 1 kW/m or greater
50% of the time the resource potential is 20 kW/m or greater
20% of the time the resource potential is 50 kW/m or greater
Monthly Power Duration Curves (KW/m)
600
550
500
450
400
350
300
250
200
150
100
50
0
600
550
500
450
400
350
300
250
200
150
100
50
0
JAN
0%
10%
20%
30%
600
550
500
450
400
350
300
250
200
150
100
50
0
40%
50%
60%
70%
80%
90% 100%
10%
20%
30%
600
550
500
450
400
350
300
250
200
150
100
50
0
40%
50%
60%
70%
80%
90% 100%
10%
20%
30%
40%
50%
10%
20%
30%
60%
70%
80%
90% 100%
40%
50%
60%
70%
80%
90% 100%
60%
70%
80%
90% 100%
60%
70%
80%
90% 100%
APR
0%
10%
20%
30%
600
550
500
450
400
350
300
250
200
150
100
50
0
MAY
0%
0%
600
550
500
450
400
350
300
250
200
150
100
50
0
MAR
0%
FEB
40%
50%
JUN
0%
10%
20%
30%
40%
50%
Monthly Power Duration Curves (KW/m)
8/18/06 0:00
8/18/06 4:00
8/18/06 8:00
8/18/06 12:00
8/18/06 16:00
8/18/06 20:00
8/19/06 0:00
8/19/06 4:00
8/19/06 8:00
8/19/06 12:00
8/19/06 16:00
8/19/06 20:00
8/20/06 0:00
8/20/06 4:00
8/20/06 8:00
8/20/06 12:00
8/20/06 16:00
8/20/06 20:00
8/21/06 0:00
8/21/06 4:00
8/21/06 8:00
8/21/06 12:00
8/21/06 16:00
8/21/06 20:00
8/15/06 0:00
8/15/06 1:00
8/15/06 2:00
8/15/06 3:00
8/15/06 4:00
8/15/06 5:00
8/15/06 6:00
8/15/06 7:00
8/15/06 8:00
8/15/06 9:00
8/15/06 10:00
8/15/06 11:00
8/15/06 12:00
8/15/06 13:00
8/15/06 14:00
8/15/06 15:00
8/15/06 16:00
8/15/06 17:00
8/15/06 18:00
8/15/06 19:00
8/15/06 20:00
8/15/06 21:00
8/15/06 22:00
8/15/06 23:00
Hourly Power (kW/m) - 8/15/06 Calm Summer
600
600
500
500
400
400
300
300
200
200
100
100
0
0
Hourly Power (kW/m) - 1/5/08 Storm
600
600
500
500
400
400
300
300
200
200
100
100
0
0
4/14/08 0:22
4/14/08 2:22
4/14/08 4:22
4/14/08 6:22
4/14/08 8:22
4/14/08 10:22
4/14/08 12:22
4/14/08 14:22
4/14/08 16:22
4/14/08 18:22
4/14/08 20:22
4/14/08 22:22
4/15/08 0:22
4/15/08 2:22
4/15/08 4:22
4/15/08 6:22
4/15/08 8:22
4/15/08 10:22
4/15/08 12:22
4/15/08 14:52
4/15/08 16:52
4/15/08 18:52
4/15/08 20:52
4/15/08 22:52
1/5/08 0:00
1/5/08 1:00
1/5/08 2:00
1/5/08 3:00
1/5/08 4:00
1/5/08 5:00
1/5/08 6:00
1/5/08 7:00
1/5/08 8:00
1/5/08 9:00
1/5/08 10:00
1/5/08 11:00
1/5/08 12:00
1/5/08 13:00
1/5/08 14:00
1/5/08 15:00
1/5/08 16:00
1/5/08 17:00
1/5/08 18:00
1/5/08 19:00
1/5/08 20:00
1/5/08 21:00
1/5/08 22:00
1/5/08 23:00
Daily Scenarios
Hourly Power (kW/m) - 8/18 through 8/21/06
Hourly Power (kW/m) - 4/14 through 4/17/08