Renewable energy is slowly getting closer to the place on the energy market that it deserves. Technology improves, reliability and efficiency increase, and consequently investments get a boost too. Limitations that were very apparent before, are now being tackled, helping the sector to reach more and more often great milestones.
A problem that has been recognized for a long time is that of energy storage and reliability of the source. Renewable energy generation is difficult to predict (although advances have been made in too), while energy storage systems are still struggling to keep up with the demand.
This, however, does not seem to remain a problem for too long. In fact, the solar power industry might have just found a way to overcome it. Meet Crescent Dunes Project, the first ever solar power plant, which generates electricity day and night, regardless of whether the sun is shining.
Developed and run by SolarReserve, Nevada-based Crescent Dunes Project provides energy to 75,000 homes. The 110-megawatt plant uses concentrated solar technology with more than 10,000 continuously moving mirrors. The energy is concentrated onto a central tower, where molten salt is heated to over 1,000 degrees Fahrenheit.
The most crucial element of the system is the molten salt, which is used in two ways. First, it acts as an energy storage, or thermal battery. The heat is retained until needed to be used. At night, or when the sun is not shining, the salt is then used to create hot steam via a heat exchanger. This steam then powers a steam turbine, which produces electricity.
This system is different from the conventional solar arrays, which convert incoming solar rays directly into electricity, but do not operate when the sun is not shining. The principle behind SolarReserve is more similar to that of fossil fuel plants, only minus the emissions. This makes it the world’s first 24-7 solar power plant.
According to SolarReserve, the project has been a brilliant investment. The numbers are follows: the investment was $1 billion, the duration of the contract that SolarReserve has signed is 25 years for $135 per megawatt hour. Crescent Dunes generates approximately 110 megawatts of energy every 12 hours, which sums up to about 1 million megawatts per year. This adds to a gross return of assets of about 13.5%.
SolarReserve is developing two more concentrated solar projects that are about to hit a milestone. One is the Redstone Solar Thermal Power Project, under construction near Postmasburg, South Africa, where it will be the first such plant in the whole of Africa. The second project is Copiapo Solar Energy, in Chile, which will have both concentrated solar and conventional solar panels. Needless to say, it will be the first of this kind in South America.
Image (c) SolarReserve