Five grid-scale energy storage technologies that can replace lithium batteries

The cost of energy storage batteries continues to fall globally. However, future energy storage methods will shift away from lithium-ion batteries and towards more innovative solutions.

That’s because current lithium-ion batteries can only store energy for a maximum of four hours. This makes it difficult for large wind and solar projects to generate base load when the wind isn’t blowing and the sun isn’t shining.

Bloomberg examines five breakthrough energy storage technologies being trialed by companies seeking renewable, grid-scale energy.

1. Compressed air energy storage

Toronto-based company Hydrostor uses electricity to compress air using water, which generates heat and stores it. When released, the heat forces the water through a turbine generator that converts the energy back into electricity.

If the energy used to compress the air is renewable, this creates an emissions-free system.

Hydrostor is using an abandoned South Australian zinc mine as Australia's first compressed air energy storage facility.

The 5MW/10MWh project in Strathalbyn is supported by the Australian Renewable Energy Agency (ARENA) and the South Australian government.

2. Liquid air energy storage

London-based Highview Power, a pioneer in solar power, uses liquid air as an energy storage medium that is cheaper and more durable than lithium-ion batteries.

According to The Guardian, the UK demonstration plant in Greater Manchester uses excess or off-peak electricity to cool the air to around -196 degrees Celsius. They are then stored in metal containers in liquid form.

Pumping and heating turns the liquid back into a gas. This releases energy to drive a turbine, generating clean electricity when needed.

Highview Power is reportedly building a commercial plant in the U.S. Sites in Europe and Australia are also under consideration.

3. Mine Gravitational energy storage

Edinburgh-based Gravitricity Ltd is experimenting with gravitational energy in mines. The company is working towards a 50-tonne demonstrator machine.

The process uses renewable energy to lift heavy objects within the mine. This can weigh up to 3,000 tonnes.

The weight is then lowered, releasing the current for up to eight hours. The company claims the winch and cable also have a lifespan of around 50 years.

Australia's large number of abandoned mines makes it a potential winner for future energy storage.

4. Pressurized water reactor energy storage

California-based Gravity Power LLC plans to use a pressurized water reactor to store energy, which would require a steel-jacketed piston made of rock and concrete and weigh 8.5 million tons.

The piston releases the pressure to release the stored energy, which can drive a turbine to generate electricity for up to 16 hours.

The company is building a demonstration plant for this future energy storage method.

5. Tower gravity energy storage

Swiss company Energy Vault is developing a more complex gravity model - using tower buildings.

The storage process involves stacking thousands of concrete blocks weighing 38 tons each into towers up to 160 meters high.

A robotic crane then lowers them from the tower, using the weight of the blocks to drive a generator.

The system can provide up to 80MWh of electricity, which will power 60,000 homes for up to 16 hours.

Energy Vault is building its first commercial plant in Milan, Italy, this year.

Note: All pictures are from the official websites of various companies.

(Original text from: Renewable Energy News New Energy Network Comprehensive)