Demand at the World Cup and a pick-up in business elsewhere means temporary power and temperature control services firm Aggreko expects performance this year will be significantly better than previously anticipated.At the interim stage group revenue in constant currency and excluding pass-through fuel will grow by around 10%, and trading profit by about 20%, the company said.In the International Power Projects division demand has remained strong and the group expects to secure orders for a record 900 megawatts (mw) in the first half of its financial year.“As we predicted in our April Interim Management Statement, the growth-rate in the number of MW on hire has accelerated markedly during the second quarter, and we expect to start the third quarter with around 18% more MW on rent than the prior year,” the company's trading statement said.There has also been an encouraging pick-up in both power and temperature control volumes in the Local Businesses arm. In Power, average volumes in the first half rose 9% from a year earlier, though rates remain weak, both in Power and Temperature Control.Encouraged by increased demand the board has decided to raise once again the rate of fleet investment and expects fleet capital expenditure this year will be around £265m, some £45m higher than previous expectations.