For more than a century, electrical distribution has been simple: Electricity zips from the generating plant to a lightbulb or motor, providing instant power. It stops for no one. That, however, may be about to change.
With wind and solar power growing in popularity, "grid storage" has taken on greater meaning in the lexicon of utilities and power providers. Wind turbines and photovoltaic cells, it seems, need a backup if they're going to take their place as major energy suppliers. When the sun's not shining and the wind's not blowing, they need help. As a result, a new breed of technologies -- giant batteries and flywheels -- are emerging as a way to store the energy from the sun and wind for later use.
"You cannot balance large amounts of renewables without storage," Tim Hennessy, president of Prudent Energy, a maker of grid storage systems, said in an interview. "You need a shock absorber. That's just a fact." Indeed, the need for storage is growing more obvious. The State of California signed an energy storage bill into law in 2010. Utilities in other states around the US are increasingly employing the technology, as are energy producers in virtually every country in Europe.
Saft Energy's lithium-ion grid storage systems are being used to store power from the third rail from an electrified elevated train in Philadelphia.
"There's not a single utility that we reach out to where we can't get a senior-level meeting to discuss energy storage," Chris Campbell, vice president of business development and marketing for A123 Systems Inc., which makes grid storage batteries, told us. "They're convinced it's part of their future."
A recent study from Lux Research Inc. reinforces that position. "Grid Storage Under the Microscope: Using Local Knowledge to Forecast Global Demand" predicts the market for grid storage of electrical power will soar over the next five years, spiking from $2.8 billion in 2012 to, almost unbelievably, $113.5 billion in 2017.
"In most regions, intermittent renewables will need to have some type of storage or new infrastructure if they're ever going to reach huge numbers -- 10 percent or 20 percent or 30 percent of our overall power," Brian Warshay, lead author of the study, told us. "Storage helps mitigate the unpredictable nature of renewable energy resources."
To be sure, the idea of grid storage isn't new. Utilities have long used "pumped hydro" and compressed air as a means of storing grid energy. In truth, such systems aren't storing electricity, per se. Instead, they're converting energy to another form -- pumping water up a hill, for example, and then letting it flow back down to spin generators when needed. But the percentage of power supplied by such systems has been puny, partially because of "siting challenges."