Solar Thermal Panels Definition
Solar thermal panels are instruments that convert the sun's energy to create heat that’s usually utilized in houses to generate hot water.
How It Works
Solar thermal panels use the sun's energy to heat up a liquid (generally water).
When the solar collector absorbs the energy from the sun, it heats a transfer fluid that is composed of water and glycol (antifreeze). The heated liquid runs through a system of pipes and tubes to a heat exchanger inside the house's water tank.
The heat from the exchanger will warm the water stored in your tank. When the transfer fluid releases the heat, it flows back to the collectors for reheating. A controller will ensure that the liquid will circulate to the collector when sufficient heat is available.
Solar Thermal Panels vs. Solar PV Panels
Solar thermal panels are similar to solar photovoltaic panels in that both forms of energy are converted from the sun's rays; however, thermal panels convert sunlight into heat for the generation of hot water, whereas, PV panels convert this same energy into electricity.
Solar PV cells can create electricity at efficiencies of up to 20%, while solar thermal systems are around 80% efficient for converting sunlight into heat energy.
Types of Solar Thermal Panels
There are 2 solar thermal panels that are commonly used: flat panels and evacuated tubes.
Flat Panels
The most common type of solar thermal panel is flat panels, also known as ‘collectors’. It is a heavy, rigid, robust, box-like structure. A metal plate that serves as an absorber is mounted on top and is coated in an absorbent bluish material or selective coating.
When the heat of the sun makes contact with the metal absorber, it then collects its energy. The fluid then carries the accumulated energy to the pipes that lead to the storage in the house.
This type of panel can be easily installed on roofs in a portrait or landscape orientation, or it can also be mounted on walls.
Evacuated Tubes
Evacuated tubes are glass tubes with vacuum and copper tubes that serve as insulation. Ten to thirty tubes are connected with a header pipe to form a panel. Because of this, evacuated tubes are more efficient than flat panel solar collectors.
Evacuated tube solar collectors are solar thermal panels that use two glass tubes. It uses a vacuum to produce a good insulator, creating little heat loss. This makes the system more efficient as a heating source for large buildings, such as warehouses.
Components of Solar Thermal System
There are two main components in a solar thermal system:
Collectors
One of the main elements of a solar thermal system is the collector, which is usually set up on a property's rooftop by using frames and brackets.
Solar collectors transfer heat from the sun via convection or radiation into liquid solar heat transfer fluid.
The glass pipes are immersed in an insulated receptacle to prevent loss of heat energy.
Solar Heat Transfer Fluid
Heat transfer fluid in the pipes is one crucial component solar thermal panels should have – either water or ethylene glycol (antifreeze) or a mixture of both – The fluid flows through the hot water tank and the collector.
Benefits and Drawbacks of Solar Thermal Systems
Solar thermal systems have numerous advantages, however, disadvantages are inevitable for this kind of system.
Benefits
- Its efficiency is much higher than Photovoltaic Panels.
- It is much cheaper than PV panels because of its low maintenance.
- They are more affordable and thus have a shorter payback period than PV panels.
- You can save on your energy bills
- You can be eligible for ‘Green Homes’ and yearly payments under the Renewable Heat Incentive.
- It does not need ample space.
- You can save up to approximately 600kg of carbon dioxide emissions in a year.
Drawbacks
- During the winter season, it is not as efficient as during summer since there is less exposure to sunlight.
- It cannot generate electricity.
Conclusion
Solar Thermal Panels are an excellent solution for homes. It works best in warm climates because they collect heat energy which can be used to provide hot water for your home needs.
They are non-toxic, so they do not produce carbon dioxide, carbon monoxide, or other dangerous gasses like photovoltaic panels do. Solar Thermal Panels are reliable, durable, and long-lasting.
Moreover, it does not need much space since it can be installed in your rooftop area. Another advantage is its ease of maintenance compared to other kinds of Solar Panels.
Solar Thermal Panels have a short payback period, so you can expect to recover your initial costs in a few years.
FAQs
1. What is a solar collector?
Solar collectors transfer heat from the sun via convection or radiation into liquid solar heat transfer fluid.
2. What is Solar Thermal Energy?
Solar thermal energy is energy from the sun in the form of heat, which can produce electricity and hot water for our needs.
3. How is Solar Thermal Energy Obtained?
Solar energy can be captured using solar panel systems, solar collectors, or solar evacuated tubes.
4. How Do Solar Thermal Panels Work?
Solar heat is absorbed by collectors (tubes filled with fluid exposed to the sun). This fluid then transfers this energy into a system of pipes that can heat water or air inside your home.
5. What is The Difference Between Thermal Panels and PV Panels?
Solar thermal panels transfer heat from the sun via convection or radiation and convert the energy heat, while PV panels convert sunlight directly into electricity.
