Labour leader Ed Miliband mocked the chancellor's failure to make any reference to Britain's loss of its Triple A rating with credit agencies during his hour long budget speech.
Romney is now saying that the production tax credit of 2.2 cents per kilowatt hour must end because it distorts markets and props up an industry that could not otherwise make it on its own.
This is partly the fault of a primitive banking system: there are no cheques, few credit cards, and paying by bank-transfer means an hour or so in a smelly queue.
The credit, which gives a tax break of 2.2 cents for every kilowatt-hour of energy produced by wind, was set to expire at the end of 2012 and will now include projects that complete construction in 2013.
Mr Duncan Smith is leading an overhaul of the welfare system that will see a number of benefits replaced by a new universal credit that is designed, he says, "to make work pay at each and every hour".