Advances In Batteries Promise To Reinvent The Grid

From sun-blessed Australia to medieval European cities, researchers are obsessing over energy storage—the key to the triumph of renewables over conventional fuels

David Stringer

It’s just a marketing gimmick. But it casts a spell. A pale orange-and-gold sunset bathes the macadamia plantations and avocado orchards that sweep down to Australia’s Byron Bay. The coming dusk is a cue for two sleek Tesla battery packs in the garage at Amileka, a secluded holiday villa nearby. They stir silently into action— powering the appliances in the five-bedroom home’s twin kitchens, recharging a $100,000-plus Model X SUV, driving a filter pump for an 18-meter swimming pool sparkling in the shade of a century-old native black bean tree.

From first light on this Southern Hemisphere autumn day, a bank of 33 rooftop solar panels has been capturing the sun’s energy. At times, the electricity is directed back to the local grid. But mostly it’s funneled into the garage and stored in Powerwall units, in the same type of rechargeable cells that fuel the automaker’s vehicles. The batteries—as tall as refrigerators, as thin as flat-screen TVs—will power this unusually energy-hungry villa deep into the evening.

But not all night. The solar array and batteries meet just half of Amileka’s average energy needs. So after a few hours, the 25-acre, $1,160-a-night miniresort that Tesla Inc. uses to promote its products must tap into the local electricity grid.

The photogenic demonstration on Australia’s eastern coast presents a vision of what some see as the most significant shift in the energy sector since the late 19th century: rechargeable batteries—in electric vehicles, homes, industrial plants, and power grids—that will make the transition to renewable energy possible.

The actual future of energy may be less postcard-worthy. It may look more like a fleet of electric school buses. And the end of utility companies as we know them.

BY 2050 SOLAR AND WIND will supply almost half the world’s electricity, bringing to an end an energy era dominated by coal and gas, according to forecasts by BloombergNEF, Bloomberg LP’s primary research service on energy transition.

It can’t happen without storage. The switch from an electricity system supplied by large fossil fuel plants that run virtually uninterrupted to a more haphazard mix of smaller, intermittent renewable sources needs energy storage to overcome two key hurdles: using power harvested during the day to supply peak energy demand in the evening and ensuring there’s power available even when the wind drops or the sun goes down.

“We think storage can be the leapfrog technology that’s really needed in a world that’s focused on dramatic climate change,” says Mary Powell, chief executive officer of Green Mountain Power Corp., a utility based in Colchester, Vt., that’s worked with Tesla to deploy more than 2,000 residential storage batteries. “It’s the killer app in a vision to move away from bulk delivery systems to a community-, home-, and business-based energy system.”

Utilities aren’t panicking yet. The prospect of large numbers of residential consumers moving fully off the grid is probably overstated, says Zak Kuznar, managing director of microgrid and energy storage development at Duke Energy Corp., a Charlotte-based utility that supplies electricity to more than 7.5 million customers in six American states. “If you are wanting to run your home just on solar and batteries,” he says, “from where the

“If you are wanting to run your home just on solar and batteries … it’s going to be tough. … At this point it’s pretty overstated” ​technology is today, it’s going to be tough. It’s something we are keeping an eye on, but at this point it’s pretty overstated.”