NiMH Battery Used to Smooth Output Fluctuation of 1MW Solar Plant

2016/11/29 15:53
Kenji Kaneko, Nikkei BP CleanTech Institute
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The 300kW improved NiMH battery system and a control board for it (source: Nikkei BP)
The system uses 440 cylindrical cells (80Ah). (source: Nikkei BP)
The output fluctuation of a 1MW solar power plant is smoothed. (source: Nikkei BP)

The Enterprise Bureau of Yamanashi Prefecture installed a nickel-metal-hydride (NiMH) rechargeable battery system with an output of 300kW at a 1MW solar power plant located in Komekurayama, Kofu City, Yamanashi Prefecture, Japan, and started a verification test to smooth the rapid output fluctuation of the plant.

Concerned parties had a ceremony to celebrate the opening of the site Nov 25, 2016.

The bureau collaborated with Exergy Power Systems Inc (Bunkyo-ku, Tokyo), a battery venture spun out of the University of Tokyo, and received help from New Energy and Industrial Technology Development Organization (NEDO). It will install an improved NiMH battery system developed by Exergy. The system is equipped with 440 cylindrical cells (80Ah).

The NiMH battery of Exergy can be more rapidly charged/discharged, compared with conventional NiMH and lithium-ion (Li-ion) batteries. The system installed this time has a capacity of 44kWh and an output of 300kW.

The problem of heat generation, which occurs at the time of rapidly charging/discharging, was solved by making improvements to the structure of the battery and improving its heat radiation performance. Because the battery realizes a high output with a small capacity, it has a potential to drastically lower the cost of storage batteries designed to smooth the short-period output fluctuation of solar power plants.