Solar Energy Profile

AgMRC, Iowa State University,

Profile revised May 2015.


Solar energy is a clean, renewable energy that may be used to supplement or replace existing power sources. Solar energy has many applications; a few include heating water, generating power to operate remote equipment and helping to reduce the reliance on overhead, electrical light sources.
solar panelsThe “solar cell” or photovoltaic (PV) cell technology was discovered in 1954 by Bell Telephone researchers. Just a few years later, PVs were already being used to power U.S. space satellites. The success of PVs in space created opportunities for commercial applications that continue to grow 50 years later.

Sales and Market Share

Even with successful applications in the space program, the solar industry did not experience rapid growth until the oil embargos of 1973 and 1979. With support from Federal and state tax incentives, the solar industry grew slowly over the next 10 years. Through consolidation of companies and restructuring of tax credit programs, the number of firms has decreased since 1990, yet the growth rate of solar collector equipment sales continues to grow.

Solar thermal collectors are divided into low-, medium- and high-temperature collectors. Low-temperature collectors that collect less than 110 degrees Fahrenheit are used to heat swimming pools and low-grade water and space heaters. Medium-temperature collectors (greater than 110 degrees F, generally 140 to 180 degrees F) are mainly used for hot water heating. High-temperature collectors (180 degrees F or higher) are used primarily by utilities and independent producers to generate electricity for a grid. Total revenue of all solar thermal collector shipments was $96.7 million in 2009, up from $81.3 million in 2008, according to the most recent U.S. government report.

Domestic shipments of solar thermal collectors were 12.2 million square feet (sq. ft.) in 2009. The residential market is the primary market for solar thermal collectors, accounting for 10.2 million sq. ft. of solar thermal collectors and 84 percent of total shipments, with swimming pool heating being the most common application.

Usage and Demand

In 2011, total U.S. net generation of all electricity was more than 4 trillion kilowatthours. Coal generated 42 percent, nuclear generated 19 percent and natural gas accounted for 25 percent. Petroleum was less than one percent. Other renewables, including hydro, accounted for 13 percent. Solar energy accounted for one percent of the renewable energy. 

Between 2010 and 2014 solar energy capacity in the United States grew an outstanding 418 percent. In 2014, said to be the best year for solar yet, the growth continued with a 42 percent growth in solar energy capacity. Even with this growth, solar energy still accounts for just over one percent of the United States electricity consumption. However, that number is expected to grow as it is predicted that solar energy will produce two percent of the nation's electricity by 2017, a significant growth in only two years.

H.R. 1424 passed into law on Oct. 3, 2008. It was an eight-year extension of the 30 percent solar tax credit. It removed a monetary cap for residential solar electric installations.


American Solar Energy Society

Electricity Explained, Energy Information Administration.

Solar Thermal Collector Manufacturing Activities, Energy Information Administration.


Links checked May 2015.

Other Useful Resources and Information

AgMRC Renewable Energy Report files

Impact of Declining Oil Prices on the Future of Solar Energy, Don Hofstrand, February 2015

Has Solar's Day in the Sun Finally Come?, Don Hofstrand, March 2015


Newsletters and News Sources

Photo Voltaics Times e-Newsletter

Photo Voltaics - Alternative Energy News

Photovoltaics - Energy Bulletin

PV Magazine

Solar Energy e-Newsletter

Solar News

Solar Power - Extreme Tech

Solar Power - Alternative Energy News


Information Files


Up with the Sun – Solar Energy and Agriculture – Union of Concerned Scientists

Solar Maps – National Renewable Energy Laboratories

Concentrating Solar Power Research - NREL

Photovoltaics - NREL

How Solar Energy Works – Union of Concerned Scientists.

Solar Energy Technologies Program - Energy Efficiency and Renewable Energy, USDOE.

Solar Water Heating – Union of Concerned Scientists.

Solar Project Property Rights: Securing Your Place in the Sun - Stoel Rivers, LLC

Solar Energy System Design, Engineering, Construction, and Installation Agreements - Stoel Rivers, LLC

Financing a Solar Project - Stoel Rives, LLC

Permitting and Land Use -Stoel Rives, LLC

Tribal Laws and Land Issues - Stoel Rives, LLC

Regulatory and Transmission-Related Issues - Stoel Rives, LLC

Power Purchase Agreements: Distributed Generation Projects - Stoel Rives, LLC

Power Purchase Agreements: Utility-Scale Projects - Stoel Rives, LLC

Monetizing the “Green” in Green Power: Renewable Energy Certificates - Stoel Rives, LLC

Foreign Corrupt Practices Act - Stoel Rives, LLC

Securities Regulation - Stoel Rives, LLC

Tax Issues - Stoel Rives, LLC




American Solar Energy Society

Argonne National Laboratory

Concentrating Solar Power and Sun Labs – Sandia National Laboratories

Cost of Solar

Energy Future Coalition

National Solar Thermal Test Facility – Sandia National Laboratories

Photovoltaics – Sandia National Laboratories


Solar Energy Industries Association

Solar Energy Technology Program – U.S. Department of Energy (DOE)

Solar Gardens Community Power

Solar Powering American Home - U.S. DOE.

Solar Estimate Calculator

Solar - U.S. DOE.

The Solar Guide


Other Links

Businesses/Case Studies

  • Dairy Farmers Milk Free Energy, Energy Efficiency and Conservation Authority, New Zealand, 2009 - The four dairy farms described in this New Zealand case study use a variety of solar water heating and heat recovery systems to reduce energy costs.
  • Owning a PV/Wind Hybrid System: Being Your Own Utility, Wisconsin Focus on Energy, 2003 - Instead of extending an electric line from the local utility, a Wisconsin couple installed a PV and wind system to power their residence.
  • Pinehold Gardens, Farm - This community-supported farm in Oak Creek, Wisconsin, added a second photovoltaic solar system in 2006.
  • Solar Innovator: Alta Devices, U.S. DOE, YouTube, June 2012 - Alta Devices produces solar cells that convert sunlight into electricity at world-record-breaking levels of efficiency.

Links Checked May 2015