Green Cool Hip

I’m sure by now everyone has heard about solar panels and how they generate electricity, or even seen one mounted on a roof or a pole.

How about a solar mirror?

A company in Spain has introduced a technology known as Concentrated Solar Thermal Energy which uses the heat from the sun to run turbines that in turns generates electricity. The cool thing is that no greenhouse gas is produced during the process.

Abengoa Solar develops, builds and operates solar plants and installations throughout the world and believes it has the solutions to climate change. Among, their current Concentrated Solar Power or CSP technologies, are Power Tower and Power Through systems. It collects and transfers solar radiation energy to a fluid which is in turn used to turn a conventional power cycle.

The first commercial plant, a power tower plant  (Figure 1) has been in operation for about two years and produces about 11megawatt of electricity, enough to power roughly 6000 homes.

Figure 1.

How it works. A field of movable mirrors referred to as a heliostat field, reflects the solar radiation on a receptor located on the upper part of the tower. It is this heat that will contribute to the generation of steam that expands on a turbine to produce electricity.

A metal tower acts as a support for the receiver. With all that heat, comes the natural need to use water to cool the tower and keep it from melting. However, a cloudy sky or the onset of dusk does not presage an end to the production of electricity. Molten salt storage tanks (Figure 2) are used to store heat collected from the solar field during the day. This system produces the heat needed to generate steam to run the plant at night and produce electricity.

Figure 2.

Currently, Abengoa has a 280 megawatts-electrical output plant planned for Gila Bend in Arizona, which will be the largest solar power plant in the world. It will deliver clean power to 70,000 homes and reduce CO2 emission by 400,000 tons.

Although this will be based on parabolic through technology which allows curved mirrors to track the sun movement, the principle ise the same as a Power Tower. Radiation from the sun is collected and concentrated onto a reflector to generate heat which eventually leads to the production of electricity.

Figure 3.

This plant will create about 1500 jobs during its construction phase and 80 to 100 permanent jobs to keep it humming.

According to Abengoa Solar, “Just using 2% of the radiation that reaches the world desertic area could satisfy current world energy needs”.

Not to be political here, but imagine how far the U.S. could have been with Solar Technology, had president Reagan not ordered the solar panels installed on the roof of the white house by Carter, removed.