Sustainability in Action at ESF
Energy from the sun Photovoltaics are materials that produce electrical current when exposed to solar energy in the form of sunlight. This phenomenon was first discovered by French physicist Alexandre-Edmond Becquerel in 1839. In 1954 Bell Laboratories developed the first photovoltaic modules able to store energy, which were then used by the space industry to fuel satellites. Today, photovoltaics are utilized in a number of settings, even in remote locations away from the electric grid, and they come in a variety of sizes.
Photovoltaic cells are made up of layers of semiconducting materials, typically an ultra-thin layer on top of a thicker layer. These layers are treated with different chemicals, and when placed together form a semi-impermeable electric field. Think of this electric field as a one way street, allowing movement of electrons up, but not down.
When sunlight hits the panels, electrons are knocked loose from atoms in the upper layer. These electrons want to move toward the oppositely charged lower layer but are blocked by the electric field. By providing an alternative pathway in the form of an electric circuit, a conduit is formed and the movement of electrons along this path creates a direct electrical current. This can be converted to alternating current by means of a power inverter, or the electrons loop back through the photovoltaic cell and up through the electric field. The process continues as long as solar energy continues to hit the photovoltaic cell. The creation of electricity within a photovoltaic cell is a clean process. There is no combustion causing pollution, and the cells are highly adaptable for different uses.
ESF is using first-generation photovoltaic cells composed of silicon. Other types of photovoltaics utilize different materials, and the cells have continued to become thinner and more efficient. Increasingly, photovoltaic systems are being used in place of traditional energy sources or in conjunction with them, resulting in a decreased demand for fossil fuels. As advancements in capturing, storing and using solar energy improve, photovoltaic systems will continue to become more efficient and cost effective.