Parabolic Trough

The term "Parabolic Trough Solar Field Technology" is quite a mouth full. But what does it actually mean?

This article will explain what parabolic trough solar field technology is and how this form of alternative energy works to provide solar energy on a broad scale.

Parabolic troughs are a solar energy collecting devices which are used to concentrate sunlight on a specific point.

To understand a little more about this you have to know that solar energy is split up into several different fields or methods.

1. Photovoltaic Solar Energy: this is where solar panels are used to convert sunlight directly into electricity.

2. Solar Water Heating: This is a method of heating up water through the use of solar energy, usually done through flat-plate collectors on the roof of a house. It is a very efficient and energy saving way of heating water even in colder climates.

3. Concentrated Solar Power: Concentrated solar power is created by focusing (or redirecting) direct sunlight onto a certain area, in order to heat liquids or gasses, which are then used to generate electricity. Currently this last method is one of the cheapest ways to convert solar energy into electricity.

Concentrated Solar Power

Parabolic troughs belong to the last category I mentioned, concentrated solar power. It is one of the ways of redirecting sunlight and focusing it on a central point.

The focal point (the point where all the sunlight converges) will become extremely hot - hot enough to melt steel, in fact, if a large enough parabolic reflector is used.

To utilize the heat generated by the parabolic reflector, a tube is placed at the focal point and a liquid is pumped through the tube. Due to the amount of heat generated, the liquid inside the tube is heated rapidly, and turned into steam.

Steam then travels through a piping system to a steam turbine, where it is used to generate electricity. And that is what concentrated solar power is in all its simplicity.

Several different methods of achieving the same result have been developed, all of which fall under the category of concentrated solar power technology. Another good example are solar towers.

Parabolic Trough Solar Energy Plants

A parabolic trough power plant consists of a solar field, a number of parabolic mirrors in the form of troughs alongside each other. There are many parallel rows of these solar collectors across the solar field (see picture).

A heat collection element, in the form of tubing placed at the focal point of the troughs, fluid is then pumped through the tubing and is heated as it passes along the sections of parabolic troughs.

The heated fluid is then converted to steam and lead to steam turbines which in turn convert it into electricity.

That's the basic setup of a parabolic trough solar energy plant.