Solar Thermal Energy and Technology

Solar thermal power is an appropriate energy source for countries located in the "Sunbelt", that is, countries that are thirty degrees or more north or south of the equator, where there is high direct solar radiation all year round.

Solar Thermal Energy and Technology Narrator: For a fistful of dollars, Southern Spain has Spaghetti Western Film set. And for a few dollars more, it has the place where it's all done with mirrors. This is Europe Center, the Solar Energy Research and Development. To save the world from global warming, it has technologies which being developed here that could be used for large scale energy needs. If you live in the Sunbelt, about 30 plus degrees north or south of the equator, then concentrating sunlight on a big scale is increasingly worthwhile. There are lots of ways of doing it, but there are three main types of collector. Michael Geyer: In simple words, the purpose of this collector is to capture the sun’s energy, perform set of conversions so at the end, you can make electricity out of it. Manuel Blanco Muriel: This mirror reflects; move in such a way that reflects the light from here that goes into the mirror towards a central receiver system on top of the tower, concentrating the night that gains overall these mirrors into one receiver. Michael Geyer: The sunlight is falling into this mirror plate, and then it is focused here to this receiver which is connected here with the so called, “stirling engine” and drives the generator. Narrator: So, that’s three different arrangements of mirrors, all computer controlled to follow the sun, all concentrating solar energy to make a lot of heat that can all then drive generators to provide electricity. And it's done using a renewable source of power which is free and will last forever, the sun. But which way is the best? That’s what the research in Almeria aims to find out. Michael Geyer: What we are installing here is a 600-meter long loop of a parabolic trough test facility in which we want to test a completely new concept of parabolic trough absorbers. We are using directly water, and it is heated up by the concentrated sunlight and it will be boiled. It will exit the loop as superheated steam at 450 degree centigrade, high pressure to run a turbine with it. Manuel Blanco Muriel: We produce the water at very high pressure on temperature and we use this water to run in the steam turbines. This is one of the possibilities or this working fluid may be air and we can heat up the air using the energy from the light or the sunlight. Michael Geyer: In this receiver, we have a working gas. It's heated up here to about 650 degree Centigrade and leaves the receiver at this temperature and enters here in the cylinder of the stirling engine where it performs the mechanical work and drives the generator. Narrator: All these systems must cost a lot to build. Are they worth it? Michael Geyer: The parabolic trough collectors today demonstrated that this is the most economic way of generating bulk solar electricity. Manuel Blanco Muriel: We’ve tried to improve the technology of improving heliostat for the last 10 years n this. The final result up to now, it's the cheapest heliostat around. Michael Geyer: The dish stirling units have been designed for electricity generation in remote villages. It can be combined for example with a biogas burner or with the natural gas burner to provide electricity when the sun is not shining. Narrator: Well, it's horses to courses. Troughs are super efficient power converters receive a task, integrate with polluting power stations and dish stirlings give 24-hour electricity in remote places. If you're looking for sustainable climate-friendly power, then these machines promise to deliver.