Solar PV

Solar Photovoltaic (PV) is a technology that converts sunlight (solar radiation) into direct current electricity by using semiconductors. When the sun hits the semiconductor within the PV cell, electrons are freed and form an electric current.

Solar PV technology is generally employed on a panel (hence solar panels). PV cells are typically found connected to each other and mounted on a frame called a module. Multiple modules can be wired together to form an array, which can be scaled up or down to produce the amount of power needed.

PV cells can be made from various semi-conductor materials. The most commonly used material today is silicon but other materials, such the ones listed below, are being tested and used to increase the efficiency of converting sunlight to electricity.

●      Monocrystalline Silicon

●      Polycrystalline Silicon

●      Amorphous Silicon

●      Cadmium Telluride (CdTe)

●      Copper Indium Gallium Selenide (CIGS)

Almost 90% of the world’s PV technologies, today, are based on some variation of silicon¹. In 2011, about 95% of all shipments by U.S. manufacturers to the residential sector were crystalline silicon solar panels².

The major difference between the technologies is the material used to generate electricity out of sunlight. Each type of material has different attributes, resulting in different applications and efficiencies. In general the efficiency of solar PV technologies varies, ranging between 6-18% at the moment.

Solar PV first appeared in niche markets in the 1950s and slowly became more mainstream as it was used in off-grid applications

Unlike solar thermal technologies, solar PV relies on sunlight, which means that when the sun does not shine electricity is not produced.

One important advantage of solar PV is it that utilizes the most abundant renewable energy resource on the planet, the sun. Estimates show that there is 10,000x more solar energy coming to the Earth’s surface than global annual fossil fuel demand³.

Another advantage of solar PV’s is that it transitions electricity generation from large, centralized facilities to smaller, decentralized production sites (ie. residential rooftops). This turns former energy consumers into so-called “prosumers,” people that can produce and consume their own electricity.

Traditionally, concerns about solar PV were about cost, intermittency and efficiency, but large-scale implementation and rapid cost decline⁴ in places like Germany and USA have revealed more complex issues such as grid compatibility, lack of solar industry expertise, and the use of rare and precious metals that make up the cells.