Torresol Energy has overcome one of solar energy’s biggest challenges: operating when the sun doesn’t shine. The 19.9 MW Gemasolar concentrated solar power plant in Spain’s Andalucia province has two tanks of molten salt (MSES) that store heat energy generated throughout the day. Unlike normal plants that have less thermal storage or none at all, this stored energy enables Torresol to satisfy peak summer energy demand long after sunset. A joint venture between Spanish giant Sener and Masdar, Abu Dhabi’s Future Energy Company, the Gemasolar plant has hurdled one of alternative energy’s biggest obstacles.
The MSES consists of 60% potassium nitrate and 40% sodium nitrate. This mixture has the amazing ability to retain 99% of the heat energy generated by the CSP plant to be reused later. Essentially what Forbes calls a “battery” that lasts for about 15 hours – more than double Andasol I’s 7 hour capacity – the MSES is not considered especially toxic to the environment.
Gemasolar is expected to produce approximately 110,000 MWh of energy each year – enough to power 25,000 homes. Although a 19.9 MW plant is relatively small, this functions on par with a 50MW plant that lacks decent storage since it can feed the grid all of the time.
Text and Image via Inhabitat