A leisure centre has an electrical demand of 100 kW and a heat requirement of 190 kW which is currently supplied using power from the grid and a boiler burning gas with an efficiency of 80%. It is proposed to install a micro-CHP system of two gas engines each producing 40 kW electrical power and a heat output of 95 kW; the overall efficiency of each engine is 90%. Under the new system the excess power requirements will be met from the grid. Assuming that the cost of electricity is four times that of natural gas, calculate the percentage suing in fuel cost in changing to the new system. 140.4%)