VAAL TRIANGLE - The financial impact of double-digit electricity increases on entry and middle-income households will be huge. This is according to FNB’s Rob Gwerengwe. The National Energy Regulator of South Africa has given Eskom the go-ahead for a tariff increase of over 15%. It will allow the power utility to raise about R10-billion from customers. Gwerengwe says this increase, unfortunately, comes at a time when customers are heavily strained financially.