Mr Bowen said he wouldn't have been brave enough to assert Australia would overtake the US in a year. Wholesale energy prices have also fallen by nearly 50 per cent in the latest data to a six-year low. Mr Bowen said he would take full responsibility if Australia failed to reach the government's 82 per cent renewable energy target by its 2030 deadline. An expansion of solar power rebates to medium-scale projects for businesses was the centrepiece of Mr Bowen's address. The expansion is expected to be budget-neutral, as it will add renewable energy to the nation's grid to put downward pressure on wholesale prices.