Solar power comes from the most abundant energy source available, the sun. It requires no combustion, is non-polluting and emits no greenhouse gasses. In addition, solar is unique in its versatility as a power source. From small solar panels that can power individual devices to rooftop solar systems for houses and businesses to small community solar "gardens" to large commercial scale solar power plants, solar is positioned to contribute significantly to the overall power needs of the country.
Figure 1 illustrates the electrical generation potential (in terrawatt-years) for each energy source on Earth. Renewable sources are presented in yearly potential, while non-renewable sources are total recoverable reserves. Solar potential dwarfs all others and could provide about 1,000 times as much energy as the entire world is projected to need in the year 2050. The challenge ahead is how to economically tap this potential and use it to displace fossil fuels.
Advances in technology have been rapid over the past few years and are expected to continue with the push to address climate change. This includes improvements in photovoltaic (PV) solar panels
, different configurations and orientations of PV cells to maximize absorbed solar energy, and new products to capture solar energy on rooftops, windows, and buildings. New technology in the form of molten salt as a heating medium has now been deployed in a utility scale plant, the Crescent Dunes Solar Plant
near Tonopah, Nevada, that allows the utility to generate on-demand, reliable electricity even after dark. New PV materials such as perovskites
are being developed that will further reduce the cost of solar modules. And low cost storage systems are starting to be coupled with solar plants, which will allow electricity to be generated when the sun is shining, save it, and then transmit or use it when needed.
Some experts predict that solar power costs will reach parity with fossil fuel power cost throughout most of the world within several years. Given its renewable and non-polluting nature, rapidly decreasing cost, and political and social pressure to address climate change issues, demand will continue to increase for solar power.