Saturday, May 3, 2014

Energy storage is the right solution for solar intermittency

Many energy experts agree that intermittency is one of the biggest, if not the biggest of all, drawback of solar power. As you already know Sun doesn't shine all day long and thus can't provide electricity at evenings and nights.

This used to be true for all solar power plants but not anymore. For the first time ever, one commercial solar power plant in Spain, has been able to solve this issue. Spain's Gemasolar solar power plant has been designed to store enough heat to operate for 18 hours at full capacity without any additional power from the Sun.

We are not talking here about the large solar power plant, Gemasolar power station, in fact, has a capacity of relatively modest 20 MW, which should be enough to power approximately 25,000 of average Spanish households.

The working principle of this solar power plant is not that complicated. There are 2,650 mirrors, which cover an area of 185 hectares. These mirrors train the Sun's rays onto a central tower, where they heat molten salt to more than double the boiling point of water.

Using this principle results in more produced heat for maximum power, and with it the additional heat is stored in molten salt tanks until it can be used during cloudy periods or at night.

Using molten salt tanks as an energy storage solution is certainly one of the more noticeable designs to store solar energy and thus solve its intermittency problem. The well known organization Desertec has awarded this plant and labelled the design of this solar power plant as "a pioneer for future power stations".

This plant has been operational for three years now, working in summer and winter as well, and showing the benefits of this new energy storage technology. 

Concentrated solar power plants across the globe could use the advantages of this design and store the excess of heat in molten salts which can later be used to supply power on demand, when the power is needed the most.