The company, which has 8.9 million customers through the brands Southern Electric, Swalec and Scottish Hydro Electric, said half-year pre-tax profits fell 54% to £302.6 million after it delayed price rises until August.
The decision to raise electricity prices by an average of 19.2% and 29.1% for gas came after SSE sustained "significant losses" in its energy supply business.
The company said: "The delay itself was a further demonstration that the competitive market and the comprehensive scrutiny to which energy suppliers are subject is the best counter to upward pressures on bills."
Britain's energy companies are now under pressure to reduce annual gas bills by about £100 a household as a result of the recent fall in wholesale costs.
SSE said: "If wholesale prices for electricity and gas maintain a downward trend, SSE is optimistic that it will be able to deliver reduction in prices for domestic customers during the early part of 2009."Copyright © Press Association 2008