BAHIAN, Mark Andrew S.
CE_2G
Four Types of Solar Collectors
1. Flat Plate Collector
• Meaning: A flat plate collector (FPC) is a solar thermal device that converts sunlight into heat.
It's a relatively simple and cost-effective design, commonly used for low to medium-temperature
applications.
• How it Works: Sunlight passes through a transparent cover (usually glass) and is absorbed by a
dark-colored absorber plate. This plate heats up and transfers the heat to a fluid (usually water
or air) circulating through tubes attached to the plate. The heat is then transferred to a storage
tank or used directly for heating. The collector is typically insulated to minimize heat loss.
• Applications: Common applications include domestic hot water heating, space heating in
buildings, swimming pool heating, and preheating industrial fluids.
2. Evacuated Tube Collector
• Meaning: An evacuated tube collector (ETC) is a type of solar collector that uses multiple glass
tubes, each containing a heat-absorbing surface and a vacuum. This vacuum significantly reduces
heat loss, allowing for higher operating temperatures and improved efficiency compared to flat
plate collectors.
• How it Works: Sunlight enters the glass tube and is absorbed by the inner surface, which is
typically coated with a selective absorber material. The vacuum between the inner and outer
tubes prevents heat loss through convection and conduction. The heat is transferred to a fluid
inside the tube, which then circulates to a storage tank or heat exchanger.
• Applications: ETC's are suitable for domestic hot water heating, space heating, pool heating,
and industrial process heat, especially in colder climates or where higher temperatures are
required.
3. Compound Parabolic Concentrator (CPC) Collector
• Meaning: A CPC collector is a non-imaging concentrator that uses parabolic reflectors to focus
sunlight onto an absorber tube. Unlike parabolic trough collectors, CPC collectors can accept
sunlight from a wider range of angles, making them less dependent on precise sun tracking.
• How it Works: Sunlight enters the CPC collector and is reflected by the parabolic reflectors onto
the absorber tube located at the focal line. The reflectors concentrate the sunlight, increasing the
intensity of radiation on the absorber, leading to higher temperatures.
• Applications: CPC collectors are used in various applications, including solar water heating,
space heating, and industrial process heat. Their ability to collect diffuse radiation makes them
suitable for locations with less direct sunlight.
4. Parabolic Trough Concentrator
• Meaning: A parabolic trough concentrator is a type of concentrating solar collector that uses a
long, curved mirror (parabola) to focus sunlight onto a receiver tube. It requires a tracking system
to follow the sun's movement across the sky.
• How it Works: The parabolic mirror reflects sunlight onto a receiver tube positioned at the focal
line of the parabola. The concentrated sunlight heats a fluid (e.g., molten salt, oil) inside the
receiver tube to high temperatures. This heated fluid can then be used to generate electricity in
a power plant or for other high-temperature applications.
• Applications: Parabolic trough collectors are primarily used in large-scale solar thermal power
plants to generate electricity. They can also be used for high-temperature industrial process heat.
