A recent study highlighting the renewable energy capacity of the eastern power grid found adding new transmission capacity can help further cut costs and emissions. the National Renewable Energy Laboratory (NREL) found the grid serving the eastern half of the U.S. is technically capable of integrating enough wind and solar power into the system to meet 30 percent of the region's yearly energy needs. But one major obstacle to the large-scale use of renewables remains: getting the best wind resource from the Midwest to the East, where the power is needed.