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Solar Power and Batteries Pair Up

One of the most commonly cited problems about solar power is that it’s intermittent, meaning that it’s not always sunny when electricity is needed. That means customers can’t count on being able to generate exactly as much solar power as they need to meet electricity demand at any given time, and utilities must rely on conventional power plants to ensure that electricity is always available.

Screen-printed solar-cell manufacturer Suniva and battery maker GS Battery are teaming up to help solve that problem by pairing solar projects with batteries. It’s a common pairing for off-grid systems, which need batteries to have electricity at night, for example, or on cloudy days. But the companies also want to add batteries to systems that are connected to the grid.

GS Battery claims its batteries can help on-grid customers get a far better return on their investment. For example, customers in areas with time-of-use pricing, where they pay more for electricity used at times of peak demand, could store the solar energy and use it – or feed it back into the grid, if they get credit based on the time of use from their utilities – during those peak periods, then use grid electricity when it’s cheapest.

The companies wouldn’t estimate how much money the combination might actually save customers, saying only that the numbers will depend on the specific application and cost of the energy being saved. But they may get a better idea of the range of savings customers can expect after completing a series of demonstration projects planned across the U.S. The first system, which will include 30 kW of solar panels and 3,000 amp hours of battery storage, is slated for GS Battery’s headquarters in Roswell, Georgia.

While other projects are still under wraps, Bryan Ashley, Suniva’s chief marketing officer, told us that a system similar to the one under construction in Roswell could be available as soon as the second quarter of this year. Suniva and GS Battery ultimately plan to target commercial, industrial and potentially residential markets, with sizes as small as 3-4 kW – although many could also be in the 30 kW range, Ashley said.

Batteries have often been proposed as a solution to the intermittency problem, with companies such as Deeya Energy, EEStor, Altairnano, A123Systems and NGK Insulators all are working to develop viable grid storage, but batteries previously have been too expensive to make sense for the grid.

One thing that’s changed is a stimulus provision, which starting this month allows battery storage systems to receive the same 30 percent federal investment tax credit as solar projects.

GS Battery also claims its nano-carbon lead-acid technology will last much longer, even with frequent charging and discharging, than other lead-acid batteries, which lowers the cost. The batteries can last up to 4,000 charge and discharge cycles, “which is dramatically more than your average car battery,” said Ashley. “When combined with Suniva’s high-power solar modules, it is a much more affordable value proposition than in the past.”

Image courtesy of GS Battery.

12 Responses to “Solar Power and Batteries Pair Up”

  1. “The companies wouldn’t estimate how much money the combination might actually save customers, saying only that the numbers will depend on the specific application and cost of the energy being saved.”

    Hmm, let’s try, shall we? Assume $300/kW-hr and 4,000 charge cycles. That means a total of 4000 kW-hrs can be stored for $300. (I’m being charitable and ignoring the cost and efficiency losses of the power inverters, and efficiency of charge/discharge of the batteries.) So that means each kW-hr stored costs 7.5 cents just for the batteries. If you add in all that other stuff, I’m sure the total cost is much worse. No bargain.

    You are far better off putting extra energy generated into your PHEV (or fridge, or AC unit, or pool heater….) and getting any electricity needed at night from the grid. The grid will even be happy as you are drawing at off-peak hours and supplying yourself at on-peak hours.