Solar 101: How Does a Solar Power Work?
Solar power plants employ different technologies like solar thermal systems and photovoltaic plants to transform the sun’s energy into electricity. To understand more about how solar power plants work, read the following information.
What Exactly is a Solar Power Plant?
A solar power plant is a facility that harnesses the sun’s rays to generate electricity. There are typically two types of solar power plants; photovoltaic solar power plants and solar thermal power plants.
Photovoltaic Solar Power Plants
This power plant uses a photovoltaic cell, or PV, to directly convert solar energy to electricity. Also known as a solar cell, this cell is constructed from silicon alloys. There are two types of photovoltaic solar panels. They include:
Crystalline Solar Panels
These solar panels are made from crystalline silicon and are available in two forms; monocrystalline and polycrystalline.
The monocrystalline solar panels use the first solar PV technology. They are considered the most efficient, offering up to 20% or more efficiency. This solar is constructed by growing a crystal.
On the other hand, the polycrystalline solar panel is the best value since it uses fewer materials and energy than monocrystalline. To make this solar panel, molten silicon is poured into a cast, giving it a grainy appearance.
Thin-Film Solar Panels
Thin-film solar is made from different materials, especially Amorphous Silicon, Copper Indium Gallium Selenide, and Cadmium Telluride (CdTe). As a result, these solar panels are portable and lightweight and an excellent choice for projects that require less power.
In addition, with a maximum efficiency of up to 20.3%, this technology is considered less expensive. The solar panels generate electricity which is stored in batteries or fed directly into the national grid.
How Does Solar PV Work?
Generally, solar PV power plants operate in the same manner as smaller PV panels. In addition, most solar PV panels are made from a semiconductor material, which is usually silicon.
When photons, which are solar energy particles, strike the silicon, free electrons are produced. The electrons flow through the semiconductor material to generate a direct electric current in what’s called a “photoelectric effect.”
Solar Thermal Power Plant
Solar thermal power plants convert sunlight indirectly into electricity. This power plant collects sunlight to generate steam which it then feeds to the turbine to produce electricity. There are three types of solar thermal power plants including;
- Solar Dish Power Plants
- Parabolic Trough Solar Thermal
These three types use the following types of systems:
Parabolic Trough Systems
These are systems that utilize parabola-shaped reflectors that can tilt and track up to 30 to 100 times the usual sunlight. The systems heat a fluid that is then collected to produce high pressure.
The heated fluid is then taken to a heat exchanger to heat water, where it boils water in a traditional steam-turbine generator. This, in turn, produces electricity.
Linear Concentrating Systems
These systems comprise sun-tracking mirrors that are positioned in a north-south orientation for maximum sun tracking.
Also known as “Fresnel reflectors,” these systems use long, rectangular, U-shaped mirrors to collect solar energy. They also utilize the Fresnel lens effect and can focus sunlight up to 30 times the usual intensity.
Solar Power Towers
This method uses hundreds to thousands of flat mirrors to focus and concentrate solar energy in a central tower.
As a result, these solar power plants work well in harsh weather conditions and can concentrate up to 1500 times the regular sunlight.
Solar Dishes and Engines
As with the other systems, solar dishes use dish-shaped mirrors to reflect the sun’s energy on collectors. However, here, the sunlight is concentrated on a thermal receiver, which is at the focal point of the receiver.
The heat generated is then transferred to an engine generator. The heated fluid on the receiver moves the piston in the engine to generate mechanical power.
These solar power plants use salinity-gradient technology to collect and store solar thermal energy. It uses a pool of saltwater to create a vertical salinity gradient referred to as halocline. This has high-salinity levels at the depth and low-salinity levels at the top.
So, when solar rays get into the pool, solar energies are concentrated at the bottom. This lowers the heat loss, enabling the water to reach up to 90 degrees. Then, the hot saltwater is what’s used to generate electricity.