Existing renewable technologies could significantly reduce the carbon dioxide emissions of the US electricity sector without increasing the cost of electricity, according to a new paper published online this week in Nature Climate Change.
It has been suggested that new, expensive energy storage technologies will be needed to develop electricity grids that rely predominantly on power from renewable electricity sources. However, such storage technologies can increase the cost of electricity, and make decarbonizing the grid prohibitively expensive. Previous studies have focused on how to stabilize the grid with a combination of renewables and storage, but, until now, no study has looked at the emissions implications of matching demand with intermittent supply from existing renewable technologies over a large area.
Alexander MacDonald, Christopher Clack and colleagues looked at the level of emissions cuts that could be achieved across the US using only existing technologies. They simulated intermittent electricity generation to find the lowest-cost ways to match demand with supply, depending on where renewable generation is most plentiful.
They find that emissions from the US electricity sector could be reduced by 80% in 2030 compared to 1990 levels, with no additional electrical storage and at a nine per cent lower cost than a fossil-fuel-based grid. They achieve most of the simulated reductions by connecting a large number of low-cost renewable energy sources to high-energy-demand centres, using new, efficient transmission systems, but also rely on some natural gas, nuclear power and hydropower to complement renewable energy generation.
In an accompanying News & Views article, Mark Jacobson writes that the study “pushes the envelope to show that intermittent renewables plus transmission can eliminate most fossil fuel electricity while matching power demand at lower cost than a fossil-fuel-based grid, even before storage is considered”.