Energy/Industry Renewable Solar Energy Storage Environment

United Arab Emirates Pilot Project Stores Solar Energy in Desert Sand

August 22, 2016

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August 22, 2016 – The city of Masdar is Abu Dhabi’s great experiment in building a sustainable urban environment for an extreme climate. Designed to incorporate a bit of the old and new to create energy efficiencies, Masdar City is located smack in the middle of the United Arab Emirates desert. Its structures are designed with a minimal energy footprint. And the energy technology it is inventing is using desert sand in a new way.

Developed at the Masdar Institute of Science and Technology, the technology, named SANDSTOCK, is being tested in two pilot projects. The principle is simple. Sand in a higher basin as it drains to a lower repository is heated to temperatures of between 800 and 1,000 Celsius (approximately 1,470 to 1,830 Fahrenheit) degrees using solar power. The retained heat can be drawn upon as an energy reserve for overnight or to supplement peak period demand.

Sand as a heat sink for renewable energy isn’t such a crazy idea. One company, Latent Heat Storage, has developed TESS, a device that stores electricity as thermal energy using containers full of silicon. Since sand is largely silicon it appears that the Masdar experiment has company. Where TESS uses molten silicon, the Masdar project uses the natural sand in its own desert backyard.

Creating reliable, inexpensive, energy storage to close the loop on the intermittent nature of wind and solar energy is critical to moving away from reliance on fossil fuels in our efforts to tackle climate change global warming.

The Masdar project was inspired by sand moving through an hourglass. States Nicolas Calvet, Assistant Professor of Mechanical Engineering, Masdar Institute, “it uses two reservoirs connected to one another vertically across a narrow passage that allows the movementof ‘cold’ grains of sand from the upper reservoir to the lower ‘hot’ one.” The cold sand particles are heated by a solar collector and stored in the lower reservoir. The heat energy is then used to heat liquid, air or gas which gets injected into a turbine connected to an electrical generator.

If the pilot project is successful, Masdar hopes to introduce this technology globally anywhere sand is available in great abundance. As Calvet explains, “sand is available everywhere in the United Arab Emirates. Sand is cheap and sand is stable at high temperatures.”