Salt Battery

A power plant in Germany recently began testing a new technology for replacing fossil fuels as an energy source. The system uses salt and water to store thermochemical energy from renewable sources for hours, days or even months before it is released again as heat at temperatures as high as 900 degrees Fahrenheit (450 degrees Celsius).

At the heart of the technology is a non-toxic, nano-coated salt called SaltX that retains its crystal form even when exposed to water. It can be charged and discharged thousands of times without sacrificing performance, and unlike ordinary salt, it will not cause corrosion.

In its uncharged state, the salt is mixed with water. To charge the thermal battery, the mixture is heated to over 900 degrees Fahrenheit (about 500 degrees Celsius), at which point the water evaporates. The salt is charged as long as it remains dry. To discharge the energy, steam or water is simply added back into the salt, and a chemical reaction releases the stored energy as heat, which can be supplied directly to homes.

Since renewable energy sources are often dependent on weather conditions, the SaltX battery system is going to be used to store energy for release when needed. The pilot system is currently serving about 100 households. If successful, the Berlin power plant plans to scale up the technology to supply heat to thousands more.