Solar energy is the light and heat that come from the sun, and it is a renewable energy source that has the potential to meet all of our future energy needs. Solar energy is created by nuclear fusion that takes place in the sun, and it is necessary for life on Earth. The amount of sunlight that hits the Earth's surface in an hour and a half is enough to manage the energy consumption of the entire world for an entire year. Solar technologies convert sunlight into electrical energy, either through photovoltaic (PV) panels or through mirrors that concentrate solar radiation.
This energy can be used to generate electricity or be stored in batteries or thermal storage. The infrared, visible and UV waves that reach Earth participate in a process of warming the planet and make life possible, the so-called “greenhouse effect”. That said, the speed at which solar panels generate electricity varies depending on the amount of direct sunlight and the quality, size, number, and location of the panels in use. In a recent successful test, as part of the Power Potential project, a solar plant's inverters were upgraded so that, in addition to providing power during the day's sunshine, the plant could also provide nighttime use, smoothing voltage fluctuations and keeping the grid stable.
Since sunlight only shines for about half of the day in most parts of the world, solar energy technologies must include methods to store energy during dark hours. Utilities are also building large solar power plants to provide power to all grid-connected customers. Solar radiation can also be converted directly into electricity by solar cells or photovoltaic cells, or used to cook food in specially designed solar ovens. To upgrade or install solar panels on the roof of a building, the roof must be strong, large and face the path of the sun.
Solar panels and cells can be attached to the roofs or exterior walls of buildings, supplying electricity to the structure. When the sun shines on a solar panel, the energy of sunlight is absorbed by the panel's photovoltaic cells. The total amount of solar energy received on Earth is much greater than the world's current and anticipated energy needs. The Department of Solar Energy's Office of Solar Energy Technologies is driving innovative research and development in these areas. This Solar Power Generation System (SEGS) generates more than 650 gigawatt hours of electricity each year.
Learn more about this groundbreaking research being conducted by this office. Solar energy is an inexhaustible source with a non-polluting nature that has great potential for meeting our future energy needs. While every place on Earth receives some sunlight for a year, the amount of solar radiation that reaches any point on the Earth's surface varies. Solar ovens typically concentrate sunlight from a wide area to a central point, where a black-surfaced container converts sunlight into heat.
