ROOFTOP PV FORECASTING
August 2012
PRESENTED BY ANDREW REDDAWAY
SLIDE 1
ROOFTOP PV AND AEMO
• Rooftop PV masks household and business demand.
• Impacts energy and Maximum Demand (MD) MD.
• Rooftop PV generation is now included in forecasts for
electricity demand.
o Separate rooftop PV from demand history.
o Include as a separate item in forecasts.
SLIDE 2
ROOFTOP PV INFO PAPER 2012
• Published on AEMO’s website:
http://www.aemo.com.au/en/Electricity/Forecasting/2012-Information-Papers
SLIDE 3
PROCESS OVERVIEW
Installed capacity
Historical
capacity
Forecast
Sunlight
Future
capacity
Historical solar
intensity
Energy generation
Historical
energy
Actual generation
Samples of
system output
Future
energy
Maximum demand
Historical
generation
Future
generation
SLIDE 4
HISTORICAL CAPACITY
There is no perfect data source for installed capacity.
Requested from all 13 DBs in the NEM.
• Monthly from 2008.
• Filled in data holes.
ORER
• Higher than DB data in early period.
• Time lags are inherent.
SLIDE 5
HISTORICAL CAPACITY - NEM
SLIDE 6
INTERESTING SOLAR INSTALL NO. 1
SLIDE 7
SUNLIGHT
• Actual monthly sunlight intensity data from BOM
SLIDE 8
HISTORICAL GENERATION - MODEL
• Initial model is simple.
• Capital city proxy for region
• Annual generation from CEC consumer guide
o kWh expected from a 1 kW system, daily avg. over a year
SLIDE 9
HISTORICAL GENERATION - MODEL
• Monthly % splits from “pvwatts” engine
o Draws on its own climate data
o Assume north orientation, tilt = latitude
SLIDE 10
HISTORICAL GENERATION – MODEL
VALIDATION
• Sample rooftop system generation data from pvoutput.org
SLIDE 11
INTERESTING SOLAR INSTALL NO. 2
SLIDE 12
HISTORICAL GENERATION
– MODEL VALIDATION, MELBOURNE
1,800.00
1,600.00
1,400.00
Monthly energy (kWh)
1,200.00
1,000.00
800.00
600.00
400.00
200.00
0.00
Date
Sample
SLIDE 13
Estimate
INSTALLED CAPACITY FORECASTS
• Forecasts of Rooftop PV growth consider the following
drivers:
o Electricity price increases
o Technology costs for solar
o Government subsidies
• And barriers
o Saturation
o Network constraints
SLIDE 14
SATURATION
Assumptions for saturation level:
• 75% of suitable dwellings have a rooftop PV system
• Average system size: 3.5 kW
• Allowance for commercial buildings
• Study by Entura: City of Port Phillip – 4 kW per dwelling.
SLIDE 15
ECONOMIC PAYBACK
For individual household installations:
Installation Year
Slow Uptake scenario
Moderate Uptake scenario
Rapid Uptake scenario
2015
8 to 11 years
6 to 9 years
4 to 7 years
2020
7 to 9 years
5 to 6 years
3 to 4 years
2025
5 to 7 years
3 to 4 years
1.5 to 2 years
2032
5 to 6 years
3 years
1.5 to 2 years
SLIDE 16
NEM INSTALLED CAPACITY FORECAST
25,000
20,000
Installed capacity (MW)
15,000
10,000
5,000
-
Year
NEM saturation
Estimated Actuals
Slow Uptake
SLIDE 17
Moderate Uptake
Rapid Uptake
NON-AEMO CAPACITY FORECASTS
23,000
Installed capacity (MW)
18,000
13,000
8,000
3,000
-2,000
Year
NEMSat
AEMO Slow Uptake
AEMO Moderate Uptake
AEMO Rapid Uptake
ACIL Tasman
Estimated actuals
Sunwiz Slow Uptake
Sunwiz Moderate Uptake
Sunwiz Fast Uptake
SKM/MMA
GEM
ROAM low
ROAM medium
ROAM high
DRET
Suntech
BREE
AER
BeyondZero
SLIDE 18
INTERESTING SOLAR INSTALLATION 3
SLIDE 19
NEM ENERGY – ROOFTOP PV
SLIDE 20
VIC ENERGY – ROOFTOP PV
SLIDE 21
VIC ENERGY – SCENARIO 3 PLANNING
Rooftop PV
5.01%
Rooftop PV
2.58%
SLIDE 22
VIC MD DAY GENERATION CURVE
80%
70%
Percentage of rated capacity (%)
60%
50%
40%
30%
20%
10%
0%
Hour
SLIDE 23
VIC MD FORECAST – ROOFTOP PV
6.79% of
total MD
3.14% of
total MD
SLIDE 24
RECAP: KEY POINTS
• Rooftop PV offsets energy and MD.
• Fast-changing area. Impacted by government policy.
• Already significant uptake (1.5 GW in the NEM),
and growing (say 12 GW in 2031).
• Lots of headroom before hitting saturation level.
• Network constraints are an issue.
• Potential to align PV generation better with system MD.
• Room to improve our analysis and understanding,
especially for MD.
• PV now included as a component in AEMO forecasts.
SLIDE 25
DIVIDER SLIDE
SLIDE 26