German polymer materials maker Covestro AG (<a href="https://www.boerse-frankfurt.de/equity/covestro-ag" target="_blank">ETR:1COV</a>) has signed a ten-year power purchase agreement (PPA) with BP Plc (<a href="https://www.londonstockexchange.com/stock/BP./bp-plc/company-page" target="_blank">LON:BP</a>) in Spain, securing solar energy for its production site in the Catalan city of Tarragona.