Republicans on the House Energy and Commerce Committee sent a letter February 22 to Jacob Lew, the White House chief of staff, asking the White House to compel the Environmental Protection Agency to provide an estimate of the total cost of its mercury and air toxics standards for power plants. The agency has said the rule as an annual cost of $9.4 billion, but no total cost estimate has been provided yet. The committee republicans cited a finding that power plants will have to raise $84 billion between 2012 and 2015 to comply with the mercury rule, which is 30 percent more than the electricity sector’s projected baseline capital spending for the period.