Solar energy is the cleanest, most abundant renewable energy source available, and it’s also very efficient. Engineers around the world are developing new technologies to make solar power cheaper and more accessible.
How does solar energy work?
The amount of sunlight that strikes the earth’s surface in an hour and a half is enough to handle the entire world’s energy consumption for a full 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.
Photovoltaic cells made from semiconducting materials convert light directly into electricity by absorbing photons with electron holes as their carriers. These cells typically consist of two layers of semiconducting material, such as silicon. A thin layer of silicon separates positive and negative charges to create an electrical field that is captured by conductive plates attached on either side of the cell. When light hits the materials in a photovoltaic panel, it excites electrons and creates new electron-hole pairs. These free carriers are collected at the electrodes on each side of the device where they power an electric current or drive a chemical reaction
Concentrating solar power (CSP) syste ms use lenses and reflectors to focus a large area of sunlight onto a small area of solar cells, generating electricity more efficiently than PV panels alone do. Whereas flat-plate solar cells can absorb energy from sunlight incident upon any part of their surface, concentrating systems use a tracking mechanism to focus the sun’s rays on small but powerful solar cells. Solar concentrators (mirrors) can be used, making CSP attractive even in low-light locations such as northern climates
The difference between solar power and conventional power
Solar power plants are similar to conventional power plants in that they consist of power-generating modules made from cheap photovoltaic material and mounted at regular intervals on support structures. But unlike conventional power generation, which is limited by fuel or steam supplies, solar thermal energy comes from sunlight directly. Solar thermal energy also differs from traditional renewable energies because it offers dispatchable output. Solar thermal energy generates electricity day and night using an advanced form of steam turbine technology . The major advantage of this approach over PV panels is that the energy from thermal solar plants can be stored for hours or even days to meet changing demand. Solar thermal storage technologies are able to deliver power on demand without wasting excessive amounts of heat.
The advantages of using solar power
Solar panels do not produce any pollution, and there are no emissions associated with using solar panels. Solar power has a low potential for negative environmental impacts. Solar power does not depend on a finite fuel source, so it will never run out as long as the sun keeps shining. Solar panels only take up a tiny amount of land space compared to other forms of energy production, such as coal plants that cover hundreds of square miles. Solar power can be used to meet energy demands on a large scale. Solar energy is available 24 hours a day, 7 days a week – which means that solar electricity can be stored for later use when needed most.
Solar power is an abundant resource that will never run out. Solar panels are made of non-toxic chemicals and metals that are found naturally in the environment . Solar panels are recyclable at the end of their lifetime, so almost all of them can be recycled without wasting materials or harming the environment.