Towards a Bankable Solar Resource

Transcription

1 Towards a Bankable Solar Resource Adam Kankiewicz WindLogics Inc. SOLAR 2010 Phoenix, Arizona May 20, 2010

2 Outline NextEra/WindLogics Solar Development Lessons learned TMY - Caveat Emptor Discussion 2

3 SEGS Solar Facilities Capacity Solar array Solar array = 310 MW solar thermal = approximately 97,000 tubes = approximately 936,000 mirrors Commercial Production Since

4 DeSoto Next Generation Solar Energy Center Capacity = 25 MW of solar photovoltaic Solar Field = approximately 180 acres Solar Array = approximately 90,000 panels Commissioned October 29 th,

5 Space Coast Next Generation Solar Energy Center Capacity = 10 MW of solar photovoltaic Solar Field = approximately 60 acres Solar Array = approximately 40,000 solar panels Commissioned at the Kennedy Space Center April 8 th,

6 Martin Next Generation Solar Energy Center Capacity Solar Field Solar Array = 75 MW of solar thermal = approximately 500 acres = approximately 180,000 mirrors The Prius of power plants Online by end of

7 Analogy to Wind Energy Assessment This is all quite analogous to the process of estimation of the wind characteristics prior to building a wind farm In both cases no single source of data can answer all of these questions Short-term on-site measurements Longer-term reference data sources NREL NASA Private sources All of the data sources have their strengths and weaknesses and must be used with care, often with inputs from auxiliary sources of meteorological information to help inform the decision Geostationary satellite data gives solar a big edge over wind With solar, at least we are not trying to measure something 80m above ground level! 7

8 Geostationary Satellite Advantage Visible Satellite RUC2 Model (Analysis) Sub-hourly, 1 km resolution Hourly, km resolution 8

9 Solar Resource Thermal & Concentrators Direct Normal Irradiance (DNI) Traditional Silicon & Thin Film Global Horizontal Irradiance (GHI) CA OR NV ID UT AZ WY CO NM TX CA OR NV ID UT AZ MT WY CO NM SD NE KS OK TX AR LA MS AL GA NC SC FL NJ MD Solar Resource Source: National Renewable Energy Laboratory (NREL) Strong Mid Range Poor 9

10 Long Term Solar Trends Source: Dr. Richard Perez 10

11 Long Term Solar Trends Mojave Desert Thermal (DNI) Solar Resource Percent Change (from TMY) Mt. Pinatubo Eruption 11

12 Situations we have encountered Snow cover The satellite estimated irradiance (below) is roughly 1/3 of that measured by the radiometer 12

13 Situations we have encountered Smoke from Wildfires Magenta : pyrheliometer observed DNI Blue: DNI from satellite analysis Significant departures May - July (between the arrows) This was a period of very large and numerous wildfires in California It appears that the pyrheliometer was affected while the satellite estimates were not At another site only 30 miles away the satellite estimates do not show significant departures from the measured data Satellite estimates are more representative of typical conditions 13

14 Situations we have encountered Anomalous Weather Patterns affecting TMY properties strong El Nino Anomalously cloudy in SW Reduced irradiance Jan 1997 selected for inclusion in TMY Results in misrepresentation of typical seasonal cycle TMY3 Year Selection Station Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Las Cruces Intl

15 TMY Caveat Emptor Current NREL NSRDB TMY2 and TMY3 weighting scheme: Met data (T, Td, Ws) 50% GHI 25% DNI 25% 15

16 TMY Caveat Emptor Well characterized thermal solar site Clear Sky P50 P90 Ground Solar resource P90 = Ground (annual average) DNI Energy production P90 < Ground (> 10 % difference) Preferable to run actual data through performance models! 16

17 Discussion No single source of solar truth. Deriving defensible conclusions involves consideration of multiple data types Meteorological factors such as snow cover, climatic variability modes, particulates (smoke, pollution related aerosols) can have affects on both ground and satellite-based measurements and their affects must be carefully assessed Need to be careful with TMY data 17

18 Finally For the solar project manager who just can t wait PV Field Tilt: 25 o Annual GHI: 1755 kwh/m² Energy Produced: 6994 MWh/year Performance Ratio: 82.8 % 18

19 Discussion 19