- technically not complex, e.g. single axle tracking
- simple plant operation
- easily scalable
- Comparatively low temperatures High startup investment
- El. efficiency: 10 20 %
- high temperatures reachable
- efficiency 20 40 %
- High investments
- Only economically viable with large scale plants (>11 MW electrical)
- Focus on power generation
- suitable for roof areas
- rigid absorber
- low flow resistances
- Low solar efficiency
- High start-up investments
- Comparatively low temperatures
- efficiency: 10 20 %
- small applications
- low space requirement
- optimally tracks sun
- high reflectivity
- Low overall performance
- Not yet marketable
- only limited scalable
- efficiency: 10 12 %
Solar Parabolic Trough
Parabolic trough is a system used to collect solar thermal energy that works using the principle of collecting and focusing the solar radiation reflected from its parabolic curved surface that are lined with a reflective material such as mirrors. This radiation is then reflected into to a metal tube, called a receiver, which is suspended at the focal point of the parabolic trough,
that is encased in glass which forms a vacuum environment that isolates the metal tube from heat loss while a liquid is circulated within the tube and absorbing the energy that is focused upon it. This liquid either itself eventually turns into steam or causes another liquid to turn into steam which then powers a turbine connected to a generator to generate electricity.
Parabolic Trough Historical
Solar Thermal Power Station in Maadi / Egypt
- Construction in 1912
- 5 lines with 60 m length
- Mirror span of 4.0 m
- Hot Water buffer for the night
- Automatic drive to follow the sun
- Low pressure steam engine with 55 hp for irrigation pump
- Flow rate 24,000 l/min
Predicted cso installed capacity
Parabolic trough technology is appropriate and commercial because this system combines DNI radiation though receiver tube (in center) without any loss like Solar Tower technology. In our opinion, Parabolic trough technology investment is more effective than other solar thermal technology for Thailand.
Central Tower, which light reflected from mirror of the Heliostats to the Central Receiver at all during the day. But for this reflection is based on the angle of incident light and the position of the Heliostats. Controls and mechanical drive installed in it. In the area of lighting design is usually between 40-70 m2 which caused the temperature in the range between 290 - 570 °C . The materials of Heliostats separate two types.
a.) Glass (Glass heliostats) is a rectangle. It has high reflection efficiency.
b.) Plastic (Plastic heliostats) is reflect the lower strength and glass.
This system has potential loss. (Collector subsystem energy losses)
- The cover of the shadow of the heliostats.
- When the surface is perpendicular to the incident of the heliostats, solar light, but let's make an angle with the solar flux by the Central Receiver heliostats will reflect less light at right angles to the surface and perpendicular to the sun.
- The incident light is reflected from the heliostats heliostats on the back of the front. Can not be sent to the Central Receiver.
- May be absorbed incident.
- The effects of steam, smoke, etc. between the Central Receiver heliostats, which reflect the direction of radiation.
Linear Fresnel is resemble parabolic trough. Increase temperature need more time, Linear Fresnel reflectors use long, thin segments of mirrors to focus sunlight onto a fixed absorber located at a common focal point of the reflectors. Curved mirrors are more efficiently focus the radiation onto the absorber with a high concentration and good intercept factor.
A parabolic dish (Parabolic Dish) is power system that converts the energy from the sun's rays and convert them into heat energy into mechanical energy to electricity. The system consists of a parabolic dish and the engine light Sterling (sterling engine) with a generator. By the parabolic dish and light.
The reflector consists of several pieces which form the parabolic surface structure. The Stirling engine with a generator placed at the focal point of the parabolic dish. And the dish must have a system driven by a 2-axis sun throughout the day. The parabolic dish system, which is light as a single point. A temperature of about 750 °C.