The United States could lower carbon emissions from electricity generation by as much as 78 percent without having to develop any new technologies or use costly batteries, a new study suggests. There’s a catch, though. The country would have to build a new national transmission network so that states could share energy.

“Our idea was if we had a national ‘interstate highway for electrons’ we could move the power around as it was needed, and we could put the wind and solar plants in the very best places,” says study co-author Alexander MacDonald, who recently retired as director of NOAA’s Earth System Research Laboratory in Boulder, Colorado.

Several years ago, MacDonald was curious about claims that there was no technology available that could mitigate carbon dioxide emissions without doubling or tripling the cost of electricity. When he investigated the issue, he discovered that the studies behind the claims did not incorporate the country’s variable weather very well.