Roundtable Recap: Rechargeable Buildings – They Can Keep Going and Going

Photo credit: Okinawa Soba, Flickr (CC
Okinawa Seawater Pumped Storage

With the cost of wind and solar plummeting, renewables are getting closer to playing a  major role in our energy supply. Since deep carbon cuts require a decarbonized grid, electricity storage is a basic building block of an aggressive path to lower emissions.

John Cerveny (NY BEST) says that’s a problem, since our electric grid “is like a giant factory with no warehouse. There’s absolutely no storage.” But the value of improving grid storage is large, says Cerveny: “You can do a much more efficient job of providing for people’s needs if there’s storage. The grid is sized for the highest loads on the hottest day. On average, we only utilize 55% of the energy grid’s potential energy delivery. The other 45% is kept idle, used only a few hours a year.”

So what’s the best way to add storage to the grid? Pumped hydropower—basically, engineered lakes at a higher altitude—store the most energy and can run the longest. “They have a huge positive impact on the US energy grid, but it’s hard to add more of them.” That’s because it’s hard to find new sites, although I wonder if it might get easier as the climate crisis intensifies—it’s may be easier to build one large centralized lake project than a million distributed battery banks.

Short of grid-scale solutions like pumped hydropower and underground compressed air storage, current technology is ready at the building scale. In NYC, a 100kW battery storage system at the Barclay Tower shows a 4-year payback without any incentives. And it uses “prosaic” lead-acid batteries—nothing exotic, and which Cerveny says has an “astronomical recycling rate – 95 to 98 percent.”

Regardless of the technology used, energy storage has other benefits, including managing demand charges, providing resiliency, reducing the size of electrical service equipment needed to handle peak loads, and facilitating renewable energy integration. “If you have a generator, it sits there and waits for an event. Battery storage provides revenue to help pay its way” and is still available in an emergency, says Cerveny.

Storage works well in concert with combined heat and power, allowing buildings to decouple these functions if they are not needed at the same time. And cogen plants can still run efficiently.

Financially, storage seems to pencil out well. Cerveny referenced a study that says there’s potential for energy storage to provide 10,000 jobs in New York State by 2020. In terms of financing, Green Bank, NY-SUN, CHARGE NY are options, and there are generous NYSERDA and utility incentives for demand management. But if you’re interested in energy storage for your building and want those juicy incentives, move fast—they must be installed by June 1, 2016.