Molten Salt Helps in Use of Solar Power During Night

Producing solar electricity during the eclipse of the sun is made possible by the introduction of a new thermal power plant situated in Syracuse, Sicily and nicknamed as Archimede in memory of the scientist who tried to burn rival ships by utilizing mirrors with concentrated sunlight.

The solar plant utilizes molten salt as storage medium to stockpile heat generated by a collection of gigantic parabolic reflecting mirrors to ensnare and focus the solar energy. The trapped and concentrated sun energy is focused to a high level heat protected tubes having molten salt. The concentrated heat takes the level of heating the molten salt up to 500°C to produce steam for the purpose of driving the attached turbines. Unlike the oils molten salts does not create cluttered seepage and consequent cleaning problem. Molten salts retain heat for a longer duration thus making it possible to make thermal power generation even after the sun set. But molten salts start solidifying when the temperature goes below 220°C, thus requiring gas heating for the initial start up.

The cost of setting the plant and the required infrastructure are two detrimental factors that affect the implementation of plants of this type. The Archimede plant was constructed with an investment of over USD80 million and an infrastructure requiring 30,000 sq.m of special parabolic mirrors and 5,400 m of dedicated piping to produce 5 MW of power. Continuous researches are taking place to reduce the cost of investment.