Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade
However, the threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars
When the price of oil increases, reserves of oil not previously worth exploiting become economically viable.