California has embarked on a massive project that mandates 1.3 gigawatts of solar storage by 2020. And storage on a smaller scale is proceeding at warp speed. In early February, entrepreneur Elon Musk announced that his latest project is mass production of 10-kilowatt-hour home-battery packs—designed by Tesla and manufactured at a giant “gigafactory” in Nevada—that will power a house for two full days without sun. 500 homes outfitted with these batteries are already proving up the tech in California. Musk expects them to go commercial in about six months.
They will be standard on all homes built by his company, Solar City, within five years. Solar City has been following a highly successful business model: install panels on people’s roofs, lease them for less than they’d be paying in energy bills, and sell surplus energy back to the local utility. Founded only in 2006, Solar City now has 168,000 customers and is the largest solar installer in the US by far.
In addition, Tesla batteries are increasingly used by businesses, like Wal-Mart, which store energy when it’s cheap and then tap reserves during peak load periods, when electricity costs more, in order to slash expenses—which utilities support, as it helps them prevent brownouts at inconvenient times, like a sweltering hot day with all those air conditioners running. The savings involved are so great that demand for collector/battery systems like this, from stores, schools, hospitals and so on, is essentially unlimited.
Nor is the alternative energy revolution confined to solar. For example, Iowa generated only 4% of its electricity from the wind in 2005; today, the figure is 28%. At the household level, wind power is still in its infancy. But efficient, frictionless turbines that utilize mag-lev technology are on the way. They will be cylindrical, rather than today’s more common propeller designs, turning in very modest breezes. As costs come down, they will become practical for home usage, especially with battery storage for calm days.