Using the Stirling Engine for Energy Storage
Presented here is transforming renewable electricity into heat or cold, preferably including a phase change of the storage material, using a Stirling engine.
A very simple, low-temperature Stirling engine. I have 2 identical ones of those, one for 30 euro from Amazon, the other one from Banggood for 10 euro. The latter actually works, the quality greatly varies. Great tool to impress your colleagues with a cup of hot coffee as heat source, which makes it run for more than 30 minutes.