How much electricity does a photovoltaic (PV) system generate?
A 10% efficient PV system in most areas of the United States will generate about 180 kilowatt-hours per square meter. A PV system rated at 1 kilowatt will produce about 1800 kilowatt-hours a year. Most PV panels are warranted to last 20 years or more (perhaps as many as 30 years) and to degrade (lose efficiency) at a rate of less than 1% per year. Under these conditions, a PV system could generate close to 36,000 kilowatt-hours of electricity over 20 years and close to 54,000 kilowatt-hours over 30 years. This means that a PV system generates more than $10,000 worth of electricity over 30 years. Other Resources: Consumer’s Guide to Buying a Solar Electric System. September 1999. NREL. (PDF 704 KB). Look on page 9 for a map titled, “Calculating Electricity Bill Savings for a Net-Metered PV System”. Download Acrobat Reader.
A 10% efficient PV system in most areas of the United States will generate about 180 kilowatt-hours per square meter. A PV system rated at 1 kilowatt will produce about 1800 kilowatt-hours a year. Most PV panels are warranted to last 20 years or more (perhaps as many as 30 years) and to degrade (lose efficiency) at a rate of less than 1% per year. Under these conditions, a PV system could generate close to 36,000 kilowatt-hours of electricity over 20 years and close to 54,000 kilowatt-hours over 30 years. This means that a PV system generates more than $10,000 worth of electricity over 30 years.
A 14% efficient PV system in most areas of the United States will generate about 250 kilowatt-hours per square meter. A PV system rated at 1 kilowatt will produce about 2500 kilowatt-hours a year. Most PV panels are warranted to last 20 years or more (perhaps as many as 30 years) and to degrade (lose efficiency) at a rate of less than 1% per year. Under these conditions, a PV system could generate close to 50,000 kilowatt-hours of electricity over 20 years and close to 76,000 kilowatt-hours over 30 years. This means that a PV system generates more than $10,000 – $12,000 worth of electricity over 30 years. Typical PV modules have efficiencies of 14% – 16%.
