Solar System Design Tools Solar Electric (photovoltaic) System: National Database of Solar InsolationPVWATTS – A Performance Calculator for Grid-Connected PV SystemsSolar Design Tools from SolarTribuneLatin American Battery Design Worksheet Solar Heating Systems: Solar Thermal DesignSizing Solar Water HeatersSizing Solar Pool Heaters Other Solar Designing: Designing a PV system for a refrigeratorMini Solar Design ConceptsNational Solar Energy Centers