One of the challenges to achieving high levels of reliance on solar and wind energy is the ability to deliver power 24/7.
But a technological race is underway to create utility-scale energy storage solutions – enabling us to store surplus wind and solar power for use later on.
While battery technologies are achieving leaps and bounds (and plenty of attention) in their cost reductions and increased capacity, here are three new technologies changing the way renewable energy can be stored.
1. Molten Salt
The 100MW Crescent Dunes solar plant in Nevada reflects the sun’s energy to a central beacon, which heats up liquefied, molten salt to 550°C.
Underground, this thermal heat is stored in insulated pipes and storage vessels. Steam produced by the stored heat powers turbines, which are able to continue producing electricity 10 hours after the sun sets, enabling the solar plant to supply power around the clock!
Find out more here.
2. Compressed Air
Californian start-up LightSail Energy uses air compression to store power.
How it works: When there’s extra electricity, an electric motor drives an air compressor, and fills a giant air tank with compressed air.
To deliver energy, the process is reversed: the air compressor becomes an expander, and the electric motor becomes a generator.
While in initial development, this technology has significant advantages for longer-term energy storage. Find out more here.
3. Rail Energy Storage
Advanced Rail Energy Storage (ARES) utilises heavily weighted railcars powered through on-peak renewable energy to drive carriages uphill.
When off-peak energy is needed, these same railcars roll slowly downhill, using generators to return power back to the grid.
Through gravity, the principles of this technology largely reflect hydroelectricity, and can be scaled without any lasting environmental impact. Find out more here.
You can learn more about energy storage in our report Powerful Potential: Battery Storage for Renewable Energy and Electric Cars.