Rondo Energy, a US maker of electric thermal energy storage systems, has entered into a partnership with Portuguese electric utility group EDP Energias de Portugal SA (<a href="https://live.euronext.com/en/product/equities/ptedp0am0009-xlis" target="_blank">ELI:EDP</a>) that will see up to 2 GWh of its heat battery installations powered up across Europe.