The revenue of Eskom increased from R71.2 billion in 2010 to R91 billion in 2011 as a result of an environmental levy charged to customers which contributed R4.3 billion, as well as the sale of electricity that increased by 2,7% and below the 4,2% target. The budget shortfall was attributed to redistributions to municipalities, industrial customers (smelters and mining customers) and prepaid customers due to the slower-than-anticipated recovery of the economy. Primary energy costs for the year amounted to R35.8 billion, increasing by 19,8% compared to the previous financial year. Overall, the increase in primary energy cost was made up of coal handling, coal-fired start-ups, gas-fired start-ups and nuclear fuel costs.