As far back as the 1880s, Thomas Edison wrestled with a way to effectively take surplus energy, save it and then use it at a later date.
In a fast-developing industry teeming with technologies that promise to be the next big thing, energy storage appears to be the biggest.
What is it?
Energy storage technology takes on a lot of different forms.
The most prominent is pumped hydro, in which water is pumped uphill behind dams and then released, with the ensuing rush of water generating power.
But chemical storage — as in batteries — may be the source people are most familiar with, especially given the media attention that inevitably accompanies any announcement by billionaire entrepreneur Elon Musk.
And the $2 billion Tesla “giga-factory” outside Reno, Nev., promises to produce enough lithium-ion batteries for 500,000 cars a year.
Why it’s hot
For all of the attention energy storage has recently received, it represents a tiny portion of the mammoth electricity and power industry — 21,000 megawatts (21 gigawatts) of capacity, a little under 2 percent of the nation’s peak demand, according to the Energy Storage Association.
But energy storage is taking on a greater role as the power grid — especially in California — integrates more renewable energy sources such as solar and wind energy.
While solar and wind can produce plenty of energy, they have a big problem with intermittency. When the sun isn’t shining, solar production slumps and when the wind isn’t blowing, wind power wanes.
The trick is trying to find a way to fill in the gaps.
Stored-up energy can help do the job when wind and solar production sputters and can “smooth out” the grid when excess amounts of power are being generated.
The prospect of homeowners, many of them generating excess power from their photovoltaic systems, discovering a reliable way to store surplus energy and use it at a later time, would have profound implications for the energy grid.