Using the Sun and Salts to Generate Renewable Energy

Concentrating solar power, or CSP, is one of the many ways to use sunlight to generate cheap forms of renewable energy. While several projects currently exist around the world, an Italian energy company called Enel has changed the way CSP can be developed. Using molten salts, Enel believes that have established a method of harnessing solar power that utilizes it to the full while cutting down on some of the drawbacks of utilizing an energy source that is not always present.

The plant, called Archimede, was announced last week by Enel and ENEA, an Italian agency responsible for renewable energy development. Previous CSP projects have used a series of parabolic mirrors to focus the heat of sunlight onto pipes that would then carry oil into a chamber to power a steam turbine. Archimede is the first CSP plant in the world to use molten salt, instead of oil, to store the heat from the redirected sunlight. According to Enel, molten salt is a more effective reagent because it can withstand higher temperatures (550 degrees Celsius as opposed to oil which can heat up to around 400 degrees Celsius) and store heat for a much longer period of time. Like other plants, the molten salt is then channeled into an area that allows for the pressure generated to be converted into electricity that is used by Enel’s providers. Enel believes that by using molten salts they will be more capable of storing energy for times when the sun is obscured by weather conditions and at night.

Archimede is currently capable of generating five megawatts of renewable energy and is being directly fed into nearby electricity grids. The plant itself utilizes 30,000 square feet of parabolic mirrors that, in turn, heat up the molten salt that is being funneled through 5,400 meters of piping. In their press release, Enel also stated that Archimede alone is able to make up for the use of 2,100 tons of fossil fuel generated power while significantly cutting down on carbon emissions that would be released by other plants.

Enel also recently announced the inauguration of the world’s first industrial scale hydrogen power plant at Fuscina in Venice, Italy which is capable of generating twelve megawatts of renewable energy. According to Enel, the plant will utilize hydrogen to generate both electricity and heat while giving off zero emissions. They believe that during full operation the plant will be capable of providing renewable energy to 20,000 homes annually while reducing carbon emissions that would otherwise be given off by fossil fuel plants operating in the same area.

While there have been some reservations about adopting molten salts for use in CSP plants due to the costs associated with operating with a different material, the change does seem to hold promise. If it ends up being as successful as Enel believes in the long run, there may be a new, more efficient way of generating solar power in the future.