Solar Thermal Collector: Overview
A solar thermal collector stockpiles solar radiation as heat. The heat can be used for domestic hot water, space heating, or cooling.
Solar thermal collectors are classified by the US Energy Information Administration (EIA) according to the method used to transfer solar energy to the working fluid.
There are two types of solar thermal collectors:
– those that use solar radiation to heat a fluid directly, and
– those that concentrate solar radiation to produce high temperatures.
Solar Thermal Collector: Components
The solar thermal collector consists of a solar radiation-absorbing element, a heat transfer fluid (HTF), and insulated housing.
The solar radiation-absorbing element is usually a dark-colored plate or tube. The HTF is a fluid that transfers heat from the absorber to the storage tank or heat exchanger.
The solar radiation-absorbing element and the HTF are enclosed in insulated housing. The housing may be glazed to allow solar radiation to enter, but minimize heat loss.
Solar Thermal Collector: Types
Here are the different types of solar thermal collectors:
Flat Plate Solar Collectors
This is the most common type of solar thermal collector. They are used in solar hot water systems. They consist of a flat absorber plate, usually coated with a black or selective coating, mounted in an insulated frame.
One or more transparent covers are placed over the absorber plate to reduce heat loss. A heat transfer fluid (HTF) is circulated through the absorber plate to collect solar heat.
Concentrating Solar Collectors
Concentrating solar collectors use mirrors or lenses to concentrate solar radiation on a small absorbing surface.
They are used in solar power plants to generate electricity.
The concentrated solar radiation heats a fluid or solar receiver, which produces steam to drive a turbine that generates electricity.
Evacuated Tube Solar Collectors
An evacuated tube solar collector is a type of solar thermal collector that consists of a series of parallel, heat-conducting tubes.
The tubes are arranged in insulated housing. The space between the outer tube and the inner tube is evacuated (i.e., the air is removed). Solar radiation enters the tube and strikes the inner tube. The solar radiation is absorbed by the inner tube and transfers heat to the HTF.
Parabolic Solar Collectors
A parabolic solar collector is a type of solar thermal collector that uses mirrors to concentrate solar radiation onto an absorber.
The solar radiation is taken in by the absorber and transfers heat to the HTF.
Parabolic solar collectors are used in solar power plants to generate electricity.
Solar Collector vs. Solar Panel
Solar collectors are sometimes confused with solar panels. They are commonly used interchangeably in the energy field.
Solar collector is an umbrella term that includes solar panels and other types of solar collectors. Solar panel refers to a specific type of solar collector.
The main distinction between solar collectors and solar panels is that a solar collector absorbs solar energy, and a solar panel converts it into electricity.
Solar Thermal Collector: Uses
Solar thermal energy is a renewable and sustainable resource that can be used to meet a variety of energy needs.
Solar thermal collectors can be used for a variety of applications, including:
– Domestic Hot Water: Solar thermal energy can be used to heat water for domestic use. This can be done with a solar water heater.
– Space Heating: Solar thermal collectors can be used to heat air or fluid for space heating. This can be done with a solar air heater or a solar radiant floor system.
– Cooling: Solar thermal energy can also be used for cooling. This can be done with a solar cooling system.
Solar Thermal Collector: Factors Affecting Performance
There are a number of factors that can affect the performance of solar thermal collectors. These include:
Solar Radiation Intensity: The amount of solar radiation that strikes a solar collector is a major factor that affects its performance. Solar radiation intensity is measured in solar insolation. The higher the solar insolation, the more solar radiation is available to be absorbed by the solar collector.
Solar Radiation Angle of Incidence: The angle at which solar radiation strikes a solar collector has an impact.
Collector Orientation: The most common solar collector orientations are horizontal and south-facing.
Collector Tilt Angle: The most common solar collector tilt angles are 0° (horizontal), 15°, 30°, 45°, and 60°.
Ambient Temperature: The ambient temperature will also have consequences.
Wind Speed: The wind speed at which a solar collector is operating is another factor.
The Bottom Line
Solar thermal collectors are a type of solar energy technology that is used to collect solar radiation and convert it into solar heat.
There are different types of solar thermal collectors, including flat plate solar collectors, concentrating solar collectors, evacuated tube solar collectors, and parabolic solar collectors.
Solar thermal collectors can be used for domestic hot water, space heating, and cooling. Solar thermal energy is a renewable and sustainable resource that can be used to meet a variety of energy needs.
FAQs
1. How do solar thermal collectors work?
Solar thermal collectors work by absorbing solar radiation and converting it into solar heat. The solar radiation is absorbed by the absorber and transfers heat to the HTF. The HTF is then circulated through the collector to transfer solar heat to a storage tank or heat exchanger.
2. Do solar thermal collectors affect the environment?
No, solar thermal collectors do not affect the environment. Solar thermal energy is a renewable and sustainable resource that can be used to meet a variety of energy needs.
3. What is the most common type of solar thermal collector?
The most common type of solar thermal collector is the flat plate solar collector as they are the most efficient type of solar thermal collector.
4. Are solar thermal collectors expensive?
Solar thermal collectors can vary in cost. The most expensive solar thermal collectors are flat plate solar collectors. Its price ranges from $400 to $2500. The least expensive solar thermal collectors are parabolic solar collectors. Its price ranges from $200 to $500.
5. Can I use a solar thermal collector at home?
Yes, solar thermal collectors can be used at home for domestic hot water, space heating, and cooling.
