British battery energy storage systems (BESS) owner and operator Harmony Energy Income Trust plc (<a href="https://www.londonstockexchange.com/stock/HEIT/harmony-energy-income-trust-plc/company-page" target="_blank">LON:HEIT</a>) on Thursday said it has kicked off commercial operations at two battery sites at home, adding a combined energy storage capacity of almost 83 MW.