Grid Update Will Allow Renewables to Prevail — Even Without Storage

Solar and wind power could substantially reduce power generation emissions in the near term, according to a recent joint study by the National Oceanic and Atmospheric Administration and the University of Colorado. Once the electric grid is updated and reconfigured to deal effectively with these new energy sources, their role will be significantly expanded.

"A transition to a reliable, low-carbon, electrical generation and transmission system can be accomplished with commercially available technology and within 15 years,” said Alexander MacDonald, co-lead author of the study and recently-retired director of the NOAA’s Earth System Research Laboratory (ESRL) in Boulder, Colorado.

The research, which was published in the journal Nature Climate Change, looked at “the cost-optimized configuration of variable electrical power generators using weather data with high spatial (13-kilometer) and temporal (60-minute) resolution over the contiguous U.S.” What they found was that “carbon dioxide emissions from the U.S. electricity sector can be reduced by up to 80 percent relative to 1990 levels, without an increase in the levelized cost of electricity.”

A major focus of the investigation was the fact that utilities today are accommodating renewables by building backup generation capacity, fired by natural gas, to account for those times when solar and wind power are not available. This is somewhat counterproductive since natural gas still produces carbon emissions. Can an optimized grid reduce the need for these backup plants, and what role will storage play?

Even though solar and wind are both intermittent sources, the fact is that the sun is shining and the wind is blowing somewhere at any given time. By looking at weather models, transmission capacity and cost parameters, the team came up with a scenario that meets demand, at a cost of 10 cents per kilowatt-hour, with a carbon reduction of 78 percent compared to the 1990 baseline.

In order to achieve that result, the model required the addition of high voltage DC (HVDC) transmission lines. MacDonald compares the development of this type of DC grid to the construction of the Interstate Highway System, back in the '50s, except that this highway system would be for electrons.

This ability to move power around the country -- in response to both electrical demand and weather conditions -- could hold the key to the wholesale migration of our national electricity supply, to one that relies primarily on renewables. According to MacDonald, this can be achieved with technologies that are available today. The only breakthrough required is one of commitment to get this done.

At the COP21 climate talks in Paris, the U.S. pledged to cut carbon emissions to 28 percent below 2005 levels by 2025. MacDonald’s team found that we could cut emissions by 31 percent in the same time-frame by making changes to the electrical sector alone.

No other study, said Mark Z. Jacobson, a Stanford University civil engineering professor, “pushes the limits” like this one, considering what can be achieved with solar and wind without relying on storage.

It shows, added Jeremy Firestone of the Center for Carbon-Free Power Integration at the University of Delaware, that the goals of the Clean Power Plan, can readily be achieved, if a commitment is made to the infrastructure needed.

However, doing so will require the cooperation of numerous states, including some that oppose this type of progress.

Image credit: Flickr/Andrew Imanaka