UK company RheEnergise is quietly rolling out an interesting new approach to pumped hydro energy storage, aiming for a capacity of at least 100 MW by 2030. It works with small hills instead of mountains, making it relevant in many more areas.

It’s one of the simplest and lowest-tech ways to store energy and then recover it on demand: use cheap energy during the day to pump a bunch of water up a big hill into a tank, then release it slowly at night, letting gravity do its work and running a turbine to generate energy as and when you need it.

But RheEnergise has added a simple tweak: it doesn’t use water. Well, not by itself. It uses a proprietary “high-tech fluid” it calls R-19, which it says is both environmentally neutral and 2.5 times as dense as water.

The result: you can generate the same power from just 40% of the elevation change, using tanks just 40% of the size. That “dramatically” cuts down on materials and installation costs – and thus energy storage costs – and since the tanks are so much smaller, they’re often able to be buried underground.

[Kinda cool! ~ Beege]