Small Wind and Solar Resource Renewable Energy Workshop Walters State Community College August 25, 2010

Solar Resource Assessment NREL Solar Maps Forecasting Generation Factors affecting generation Technology Considerations

Concentrating Solar Needs to be normal to the panel; not diffuse. Single & two axis tracking required. Clouds & humidity scatter sunlight. Technology targets SW US. Heat water for steam with energy storage. Concentrate on triple junction, very high grade PV materials. Used to heat feedwater, saturated steam and or combustion air at fossil power plant.

Estimate Generation Use PV Watts http://mapserve3.nrel.gov/PVWatts_Viewer/index.html Provides estimate of annual generation. Provides your solar insolation. Use Solar Hours SH (in day, 4 - 5 hours) Times days in year Times installed capacity Times conversion efficiency factor Use Capacity Factor 14 - 15 % CF Times hours in year Times installed capacity Divide by 100.

Tool for Evaluating Shading - Solar Pathfinder Need sun Level device Graph shaded area Determine shading Solar Pathfinder

Tools for Shading – Solmetric Suneye Direct device South from Site Take pictures Software determines shading

Seasons Longer days in summer Can adjust tilt for winter & summer

Temperature Hot temperatures have detrimental effect on performance Allow for ventilation of panels on roofs

Maximum Power Point Tracking Shading, defective panel, and or short will effect the whole PV string. Most inverters have maximum power point tracking Shoals Technology has introduced MPPT technology for strings. Enphase micro inverters address possible shading.

Trackers – Add Cost Zomeworks 1 axis 15 -25 % more WattSun 2 Axis 25 – 35 % more kWh

Thin Film Versus Crystalline Thin film panels around 10% efficient Crystalline panels 13-19% efficient Therefore, area consideration Thin film panels perform a little better in cloudy conditions.

References Solar Electric Power Association Solar Energy Industries Association American Solar Energy Society National Renewable Energy Laboratory