Solar PV, or solar photovoltaic, is a technology that converts sunlight directly into electricity using photovoltaic cells. These cells are made from semiconductor materials, such as silicon, which absorb photons of sunlight and release electrons. When these electrons flow through an external circuit, they create an electric current that can be used to power various electrical devices.
Solar thermal, on the other hand, is a technology that uses sunlight to generate heat. In a solar thermal system, solar collectors, such as flat-plate collectors or evacuated tube collectors, absorb sunlight and transfer the heat to a fluid, typically water or air. This heated fluid can be used for various applications, such as heating domestic water, swimming pools, or providing space heating.
The key differences between solar PV and solar thermal are:
- Energy conversion: Solar PV directly converts sunlight into electricity, whereas solar thermal converts sunlight into heat.
- Applications: Solar PV is primarily used for generating electricity to power electrical devices, while solar thermal is used for heating water or air for domestic, commercial, or industrial purposes.
- Efficiency: Solar PV systems generally have lower efficiency in converting sunlight to usable energy compared to solar thermal systems. However, solar PV can be used to generate electricity, which has a wider range of applications.
- Components: Solar PV systems consist of photovoltaic panels, inverters, and other electrical components, while solar thermal systems include solar collectors, heat exchangers, and pumps or fans for circulating the heated fluid.
- Maintenance: Solar PV systems typically require less maintenance than solar thermal systems, as they have fewer moving parts and do not involve the circulation of fluids.
Both solar PV and solar thermal systems harness the power of the sun to provide clean, renewable energy. However, they do so through different mechanisms and serve different purposes.