As the U.S. races to bring more renewable energies online it is faced with the risk of damaging electric grids that were built for an older time, The Los Angeles Times reports.
Officials are concerned about how they will keep the grid working and electricity flowing when the source of generation — green energy — is unpredictable.
"The grid was not built for renewables," said Trieu Mai, senior analyst at the National Renewable Energy Laboratory (NREL).
And utility officials claim the only guarantee with switching to more and more renewables is that ratepayers will foot the bill.
NPR reports a similar story, asking whether the U.S. and other countries can meet targets on fossil fuel cutbacks without paying a price.
Roughly 82 percent of the world's energy consumption is fed by coal, oil and natural gas.
The key, NREL experts say, is a more flexible grid.
A larger transmission grid would need to be able to pull wind and solar energy from thousands of miles away, allowing a windy day in Wyoming to compensate for a lull in California.