"We managed to negotiate for salary increases that we think will sustain jobs and also make sure that workers are happy." Last month, Petra Diamonds struck a long-term deal for the supply of renewable energy to its South African diamond mines as it seeks to secure sustainable power supply for its operations. With South African miners susceptible to production disruptions from load shedding by Eskom, Petra Diamonds has turned to independent renewable energy suppliers while also helping to curb emissions from its operations.