How to Use Solar Energy at Night

Molten salts can store the sun's heat during the day and provide power at night

Near Granada, Spain, more than 28,000 metric tons of salt is now coursing through pipes at the Andasol 1 power plant. That salt will be used to solve a pressing if obvious problem for solar power: What do you do when the sun is not shining and at night?

The answer: store sunlight as heat energy for such a rainy day.

Clipped from: Solar Millennium AG - We re Developing the Future. - Home

Andasol 1, the first parabolic trough power plant in Europe, has initiated its test run. This solar-thermal power plant is an important reference for Solar Millennium's expertise in project development and technology. Andasol 1 will supply up to 200.000 people with climate-friendly electricity and save about 149,000 tons of carbon dioxide per year compared with a modern coal power plant.

Clipped from: Andasol Projects

	nTechnology: „Solar-only“ Parabolic Trough Power Plant
	nInstalled Capacity: 3 x 49,9 MWel
	nStorage: Two-tank molten salt storage for 7 full load hours
	nProject Site: Plateau of Guadix, Province Granada, Spain
	nNet electricity production: 3 x 157 Mio. kWh/a
	nInvestmentbudget: approx. 260 Mio. € per plant

Clipped from: How to use solar energy at night or during rainy days | Solar Power | The Green Optimistic

The molted salt technology is very simple in theory. The molted salt has 60% sodium nitrate and 40% potassium-nitrate. The salt melts at 430 Fahrenheit and is kept liquid at 550 Fahrenheit in an insulated cold storage tank. The molted salt is pumped to the top of the tower, where sunlight heats it in a receiver to 1050 degrees Fahrenheit. The 1050 F heated salt flows back down to a second insulated hot storage tank. Hot salt goes into a steam generator which produces very hot steam for a turbine.

Molted salt technology is almost 93% efficient compared to directly harvesting the sun energy. The other 7% lost during the heat transfer to water is not so significant if we compare to other technologies of storing the energy that comes from the sun.

Andasol 1 is the first solar-thermal power plant ever built, and the investments costs go up to $380 million (300 million euros).

Clipped from: YouTube - Andasol Power Plant Salt Storage Solar Millenium - solar thermal parabolic trough plant

Andasol Power Plant Salt Storage Solar Millenium - solar thermal parabolic trough plant

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2009-04-26

Andasol 1 Solar Power -- Molten Salt Technology

How to Use Solar Energy at Night

Molten salts can store the sun's heat during the day and provide power at night

Andasol Power Plant Salt Storage Solar Millenium - solar thermal parabolic trough plant