Solar energy made up 0.94% of the energy (and 8.3% of renewable energy) used in the United States in 2018 and 1.8% of electricity generated in the United States in 2019.
What is solar energy and how is it used?
Most U.S. solar energy is produced by photovoltaic cells — the fundamental elements of solar panels — which produce electricity from sunlight. Individual photovoltaic cells are at most a few inches across and made from silicon or other materials.
Other solar technologies use heat from the sun to warm buildings directly or indirectly, or to heat water or other fluids that can in turn spin electricity-generating turbines.
Photovoltaic technology originated in the 1950s in the United States and has evolved to become increasingly efficient. Estimates vary, but generally costs for utility-scale systems — those larger than typically found on the roofs of homes and businesses — have decreased dramatically. The National Renewable Energy Laboratory reports that costs sank by over 75% between 2010 and 2018. As of 2018, the cost of solar energy is competitive with the cost of fossil fuel energy generation.
U.S. solar energy consumption multiplied nearly six-fold between 2012 and 2018.
What are the advantages and disadvantages of solar energy?
Since 2010, solar panel costs have dropped almost 80%, and the cost of solar energy is now competitive with energy from conventional sources in some states.
Solar energy can be produced anywhere sunlight is available, although energy generation is limited by factors including latitude, the number of daylight hours, and atmospheric conditions.
For small-scale systems, costs like permitting and inspection can add thousands of dollars to the cost of a solar system.
A 2017 article from Sustainable Energy Reviews discusses the pros and cons of recent solar energy technologies, as well as costs and market details. A 2019 report from the Lawrence Berkeley National Laboratory, Utility-Scale Solar, analyzes changes in technology and price for large-scale solar energy generation.
The Business Council for Sustainable Energy’s 2020 Sustainable Energy in America Factbook includes recent information on the U.S. energy sector, such as market details, data on emerging technologies, and historical trends.
The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) published the 2018 Renewable Energy Fact Book, which is the most recent edition and includes summary information on the different types of renewable energy sources. The Fact Book was prepared by the National Renewable Energy Laboratory, which also gives information about each of the major renewable energy sources. The EERE also describes technologies and research in different methods of renewable electricity generation, including solar, geothermal, wind, and water.
The International Energy Agency (a Paris-based autonomous intergovernmental organization) produced the report Global CO2 Emissions in 2019, which provides helpful international context about global energy trends and development. A report from the International Renewable Energy Agency (IRENA), Renewable Power Generation Costs in 2019, breaks down the prices tied to different renewable energy technologies and processes on a global scale.