UK utility SSE plc (<a href="https://www.londonstockexchange.com/stock/SSE/sse-plc/company-page" target="_blank">LON:SSE</a>) and its joint venture (JV) partner Gilkes Energy have submitted a planning application for a pumped storage hydro station project that will add a capacity of up to 1.8 GW/36 GWh in the Scottish Highlands.