EVs don’t help the environment much unless the electricity is being produced in green, alternative ways, and solar homes won’t become common until they’re more affordable. Elon Musk of Tesla and his cousin Lyndon Rive of SolarCity are trying to power those potential markets with multiple uses of the planned Nevada Gigafactory. From “The Musk Family Plan for Transforming the World’s Energy,” Christopher Mims’ new WSJ piece:

“Thanks to the economies of scale that will come from Tesla’s gigafactory, within 10 years every solar system that SolarCity sells will come with a battery-storage system, says Mr. Rive, and it will still produce energy cheaper than what is available from the local utility company.

Mr. Musk also noted that in any future in which a country switches fully to electric cars, its electricity consumption will roughly double. That could either mean more utilities, and more transmission lines, or a rollout of solar—exactly the sort that SolarCity hopes for.

America’s solar energy generating capacity has grown at around 40% a year, says Mr. Rive. ‘So if you just do the math, at 40% growth in 10 years time that’s 170 gigawatts a year,’ says Mr. Rive. That’s equivalent to the electricity consumption of about 5 million homes, which is still ‘not that much,’ he says, when compared with overall demand for electricity. ‘It’s almost an infinite market in our lifetimes.’

There are almost innumerable barriers to the realization of Messrs. Musk and Rive’s plan.”