Solar energy is the conversion of sunlight into electrical or thermal energy. This can be done in two ways: through photovoltaic cells or solar thermal collectors. This article discusses the different types of solar energy and how they work.
What Are The Different Types of Solar Energy?
There are two main types of solar energy: photovoltaic cells and solar thermal collectors.
Photovoltaic cells, also known as PV cells, are the most common type of solar energy. PV cells work by converting sunlight into electrical energy. Solar panels, often seen on rooftops, are made up of many small PV cells.
On the other hand, solar thermal collectors collect and store heat from the sun. This heat can then be used to heat water or air. Solar thermal collectors are less common than PV cells, but they are becoming more popular to generate renewable energy.
How Do Photovoltaic Cells Work?
PV cells work by using the photovoltaic effect. When sunlight hits a PV cell, the photons from the sun knock electrons loose from their atoms.
These electrons then flow through the cell and create an electrical current that can be used to power appliances and charge our batteries.
There are three main types of PV cells:
Monocrystalline PV cells are made from a single, pure crystal of silicon. They are the most efficient type of PV cell, but they are also the most expensive.
Monocrystalline solar panels have an efficiency of around 20%. This means that they can convert 20% of the sunlight that hits them into electrical energy.
The main advantage of monocrystalline photovoltaic cells is their high efficiency. However, they are also more expensive than other PV cells and can be difficult to manufacture.
Polycrystalline PV cells are made from multiple crystals of silicon. They have an efficiency of around 15%, which is lower than monocrystalline PV cells. However, they are still a popular choice for solar panels because they are less expensive to manufacture.
Thin-film PV cells are made from a thin material layer, such as cadmium telluride (CdTe) or copper indium gallium selenide (CIGS). Thin-film PV cells are the least efficient type of Photovoltaic cell, but they are also the cheapest to manufacture.
This type of solar panel is very flexible, making it ideal for use on rooftops or in other tight spaces.
How Do Solar Thermal Collectors Work?
These devices work by collecting sun rays using mirrors or lenses and then converting them into heat. Solar thermal collectors can heat water or air for our homes or businesses.
There are four main types of solar thermal collectors:
1. Flat Plate Collectors
Flat plate collectors are the most common type of solar thermal collectors. They consist of a dark-colored absorber plate inside an insulated box. The absorber plate absorbs sunlight and converts it into heat.
The heat is then transferred to a fluid or air that flows through the collector. This can be used to heat water for homes or businesses.
2. Evacuated Tube Collectors
Evacuated tube collectors are made up of a series of tubes. Each tube has an outer glass layer and a metal absorber plate inside.
The space between the outer glass layer and the inner absorber plate is evacuated or made into a vacuum. This creates an insulating effect that increases the efficiency of the collector.
3. Line Focus Collectors
Line focus collectors, also known as parabolic troughs, are long U-shaped mirrors concentrating sunlight onto an absorber tube.
The absorber tube is filled with fluid heated by the sun and can be used to heat water.
4. Point Focus Collectors
Point focus collectors, also known as parabolic dishes, are large mirrors concentrating sunlight onto a small absorber.
The absorber is usually a photovoltaic cell that converts sunlight into electrical energy.