Solar power generation
Solar power deals with the generation of electricity from sunlight. Various methods are used for this like photovoltaics (PV) or concentrating solar power (CSP), where the sun's energy is focused to boil water which is then used to provide power.Solar power is a predictably intermittent energy source, meaning that while solar power is not available at all times, we can more or less accurately predict when it will be available.Some technologies, like solar thermal concentrators can store thermal energy in elements such as molten salts. These store spare solar energy in the form of heat which is made available overnight or during periods that solar power is not available to produce electricity.Other way is the Stirling engine dishes which use a Stirling cycle engine to power a generator.
Concentrating solar power(CSP) systems
These systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a heat source for a conventional power plant.Concentrating technologies used are the parabolic trough, the concentrating linear fresnel reflector, the Stirling dish and the solar power tower.In all these systems a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage.
A solar cell, or photovoltaic cell (PV), is a device that converts light into electric current using the photoelectric effect(some materials release electrons when hit with rays of photons from light, which produces an electrical current). The first solar cell was constructed by Charles Fritts .early solar cells reached efficiencies of 4.5â€œ6%. There are other types of solar cells like thin film, monocrystalline silicon, polycrystalline silicon, and amorphous cells. Concentrating photovoltaics (CVP) are another new method of electricity generation from the sun. CPV systems employ sunlight concentrated onto photovoltaic surfaces for the purpose of electrical power production.
A solar updraft tower (also known as a solar chimney or solar tower) consists of a large greenhouse that funnels into a central tower. As sunlight shines on the greenhouse, the air inside is heated, and expands. The expanding air flows toward the central tower, where a turbine converts the air flow into electricity.
Energy storage methods
Off-grid PV systems have traditionally used rechargeable batteries to store excess electricity. With grid-tied systems, excess electricity can be sent to the transmission grid.Pumped-storage hydroelectricity stores energy in the form of water pumped from a lower elevation reservoir to a higher elevation one when surplus electricity is available.