In the efforts of Green New Deal and electric car advocates, a new permit for power transmission lines may knock down one of the biggest hurdles to bringing more renewable power to electric cars.

Last week, a major new power transmission line from Wyoming to the Hoover Dam won final approval from Wyoming, the last of the states it traverses to approve it.

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The transmission line is key for two reasons:

- Wind is the fastest growing source of renewable energy and the most likely source to provide large quantities of renewable energy. But the biggest source of wind is in the center of the country, while the biggest demand for electricity, especially to charge electric vehicles, is in California and on the coasts. 

- In something of a virtual stress test of renewable grid capacity during this winter's polar vortex, energy consulting firm Wood Mackenzie produced a study in February showing that one of the biggest obstacles to getting enough renewable power to homes and businesses during such a period of high demand is transmission capacity. Giant wind farms in the Midwest may not have enough transmission capacity to feed the coasts during high demand periods, just as abundant solar capacity in the Southwest may not have enough transmission lines to reach frozen regions of the upper Midwest in a deep freeze. 

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Battery and hydro storage can address some of this demand, but more transmission makes it easier.

The new $3 billion power line, called the TransWest Express Transmission Project, is slated to be completed in 2023 and carry 3 gigawatts of power from two western Wyoming wind projects 730 miles to West Coast power markets. It will run from southwestern Wyoming through Colorado and Utah to Nevada to connect to existing transmission lines at Hoover Dam. 

The project already won approval from Nevada, Utah, Colorado, and the federal government.

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California, which has set a goal to be carbon free by 2045, currently gets 29 percent of its electricity from renewable sources, including about 10 percent each from wind and solar. It gets nearly another 15 percent from hydro power (some imported from the Pacific Northwest), 9 percent from nuclear power, 34 percent from natural gas, and about 4 percent from coal.

In 2018, more than 10 percent of the cars sold in the state were plug-in or electric vehicles.

The new influx of wind power from the new transmission line should not only give a significant boost to the percentage of renewable electricity available to charge electric cars, it should also dramatically increase flexibility on the grid.