A 2004 study by the Royal Academy of Engineering using "simplification and approximation" found that wind power cost 5.4 pence per kW·h for onshore installations and 7.2 pence per kW·h for offshore, compared to 2.2p/kW·h for gas and 2.3p/kW·h for nuclear. By 2011 onshore wind costs at 8.3p/kW·h had fallen below new nuclear at 9.6p/kW·h, though it had been recognised that offshore wind costs at 16.9p/kW·h were significantly higher than early estimates mainly due to higher build and finance costs, according to a study by the engineering consultancy Mott MacDonald.