Visit to Plant

Large-scale Solar Plant Blends in With Local Community (page 2)

To be the power supply next to a wide-area disaster prevention base when disaster strikes

2013/11/02 19:57
Shinichi Kato, Nikkei BP CleanTech Institute
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Generated power preferentially used to charge batteries

The equipment to house and charge secondary batteries was set up next to the entrance to this solar power plant, which has 5.2MW of maximum output. The aim is to enable the residents of the adjoining housing subdivision to be able to immediately use the batteries should a disaster strike. Small-type 2.2kW secondary batteries were chosen to be housed so the residents could carry them on bicycles.

In light of such a purpose, the key of the charger and the housing apparatus is kept by the chairman of the residents’ association. The generated power is programmed to be preferentially used to charge these secondary batteries even during usual conditions.

For the secondary batteries, a PV inverter with 50kW-rated output, which is rare at a large-scale solar power plant, was introduced. It is a home-use PV inverter manufactured by GS Yuasa Corp. The reason for its introduction is that the PV inverter is a stand-alone type that keeps on operating even if the power system network goes down at the time of a disaster.

Industrial PV inverters are designed to stop operating when the connected power system goes down. Therefore, such a PV inverter was necessary apart from the other industrial PV inverters in the plant.

In addition to this PV inverter for secondary batteries, 500kW and 250kW PV inverters manufactured by Toshiba Mitsubishi-Electric Industrial Systems Corp (TMEIC) are used in combination to generate power for sale under usual conditions.

Sept 1, 2013, or the first National Disaster Prevention Day since this solar power plant started generating electricity, an outdoor cooking test-run using the secondary batteries charged by the plant was included in the list of regular disaster drills conducted by the residents’ association of the adjoining housing subdivision (Fig. 3 & 4).

Those disaster drills are conducted by the residents of the housing subdivision, instead of Sanko Real Estate, which is responsible for the subdivision’s management and operation. Although it is a recent housing subdivision where neighboring ties are weakening, events such as a summer festival, traditional dances and disaster drills have been conducted by enthusiastic residents in Hikari no Machi since its early days. And a strong local community has been formed through those activities.

An attempt to charge and use the secondary batteries with the electricity generated at the solar power plant was also made in the disaster drills. Solar power generation has started to be accepted by the local community.

In addition, Sanko Real Estate’s Information Center in the southernmost part of the subdivision to the north of the solar power plant is being used as an environmental studies room. Groups of people such as classes from elementary/junior high schools and corporate parties visit almost every week.

“Following the opening of this solar power plant, the town became more linked to this subdivision’s name, “Hikari no Machi (town of light),” said Michitaka Nakamura, director of the General Planning Department and manager of the Environmental Energy Operation, Sanko Real Estate, outlining his expectation for synergies to be formed.

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