Power prices are expected to remain firm next fiscal on the back of elevated demand growth of 5.5-6 per cent, and the demand is set to close this fiscal up 9.5-10 per cent over 8.2 per cent last fiscal, a report said on Thursday. The fears of a heat wave has seen the short-term power prices soaring by a full 151 per cent. This was on the back of a 42 per cent on-year spike in prices in February, Crisil said in a report.