"we will have solar energy as soon as they utility companies solve one technical problem - how to run a sunbeam through a meter"
This is not a new technology for energy generation , infact this process is used to produce power in power stations where fossil fuels are burnt , coal fired power plant or diesel power plant for example. But in place of fossil fuels like coal or diesel , in this method solar heat is used to produce steam.
Have you seen solar water heater ?? well , Concentrated Solar Power Plant or CSP for short uses same method but in a larger scale to produce heated fluid which in terms , heats water flowing in heat exchanger device and generates steam which finally runs turbine ... the same way it is used at thermal power plants. This method of solar energy conversion is known as in-active or passive solar energy conversion , compared to active energy conversion like Photo Voltaic cells a.k.a. Solar Cells.
Well the roots of experiment lies at roman ages when , great inventor and scientist Archimedes used concentrated heat of sun with help of some kind of shiny metal and burn out the roman fleet !!! well its just a myth , but who knows may be it is true ... after all myths just don't got story in one night .. right ?? or another ancient example is tower of Alexandria .. just like its world famous library , the lighthouse of alexandria was also famous in ancient world and was considered as one of the seven wonders of ancient world. In that tower too they had used same concentration of heat concept.
So , inspired from ancient history , modern scientists developed whole new kind of technology to produce electricity , knows as Concentrated Solar Power or CSP for short. The basic working logic is pretty simple ... they use larger / small mirrors and concentrate heat of sun at one spot which contains some kind of liquid material ( synthetic oil or molten salt for example ) ... and then this liquid goes through heat exchanger mechanism with water and converts that water in to hight pressure steam which then runs steam turbine .. ( don't ask more details , as its whole new subject of study ) ...
Depending on design CSP is catagorized into three methods.
First one is , Tower Type , in which solar energy is concentrated in the tower placed between field of mirrors ,known as heliostats which follows movement of sun and keep their self in such a position that , they always reflect maximum solar radiation. The first CSP , Tower project in USA was Solar One ... at california which was among first generation of CSP plants . It was able to produce about 10MW electricity.
Second one is , known as Trought type , in which instead of heating single spot like in tower type , heat is concentrated on individual troughs passing though series of concave highly reflective mirrors. The CSP, Trought project in USA is built at , Nevada known as Nevada Solar One ... and another project is at Kremer Junction , California. Both CSP plants uses trought system.
Third type is , Disc Type, in which parabolic dish reflector is used which concentrates solar heat at its focal point where close cycle re-generative heat engine is placed. Which runs with help of heated fluid.The biggest system of this kind is placed near Canberra , Australia.
Out of all these 3 types , it has been said that , the Disc Type CSP system works more efficiently because of its compact and effective design.
The biggest challenge with these systems are , they require larger area of operation and clear sky of sunny weather. Also the fluid that they use for heating must be having great conductivity and heat storage capacity. And hence still researches are being done to improve performance of the whole system.
But , all these CSP systems have been proved that all these system can work very efficiently and effectively at lower cost. They gives us clean green energy that we have ever imagined , a better less polluted future.
May the force be with us ...
