Visit to Plant

2MW Solar Plant Offers Emergency Power Outlets

Solar power plant capable of supplying power during disasters

2014/08/02 21:30
Kenji Kaneko, Nikkei BP CleanTech Institute
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In March 2014, Resorttrust Inc started operating "Resorttrust Mega-Solar Nasu Shirakawa" with an output of about 2MW in the mountains in Nishigomura, Fukushima Prefecture, Japan (Fig. 1). Adopted were Panasonic Corp's polycrystalline silicon panels and Toshiba Mitsubishi-Electric Industrial Systems Corp's (TMEIC's) PV inverters, and the panels were mounted on steel mounting systems supported by concrete foundations.

These specifications are common among the mega- (large-scale) solar power plants that have been rapidly increasing throughout Japan in the wake of the implementation of the feed-in tariff (FIT) program. However, Resorttrust Mega-Solar Nasu Shirakawa has a feature that differentiates it from other mega-solar power plants: the "emergency power outlets" set up outside the fence around the power plant (Fig. 2).

EV, emergency power outlets to be offered for free during disasters

Nishigomura is located in the highlands to the south of the Nakadori area, Fukushima Prefecture. Situated on a green hill, the mega-solar power plant cannot be seen from public roads. As you walk up a narrow lane surrounded by trees, you will find the 8,320 panels laid across the 13,200m2 site, which is divided into three areas (Fig. 3). Although the solar panels and PV inverters are all inside the fence, part of the fence beside the PV inverters is concave, where 100V outlets that can be used in emergencies and a panel that explains the mega-solar mechanism are installed (Fig. 4).

Resorttrust Mega-Solar Nasu Shirakawa set up standalone power supply equipment exclusively for emergencies so it can automatically switch on when a blackout is detected. The standalone power supply equipment is connected to ten panels and can output up to 2kW.

Provided with the same 100V power outlets as those seen in houses, the power supply equipment can be used for home-use electric appliances. Resorttrust has one electric vehicle (EV), an "iMiEV," at its general resort facility "Grand Xiv Nasu Shirakawa" near the mega-solar power plant. The company plans to charge the EV, mobile phones and computer batteries with the emergency power outlets at the mega-solar power plant if it loses power during a disaster (Fig. 5).

Under the disaster control agreement with Nishigomura, Resorttrust will offer the EV and the emergency power supply at the mega-solar power plant for free if a power outage occurs (Fig. 6).

Fence, utility poles colored to blend in with scenery

By installing an information panel that shows the amount of power generated and CO2 reduction in the lobby of the resort hotel "Xiv Nasu Shirakawa" at Grand Xiv Nasu Shirakawa, Resorttrust emphasizes "a mega-solar power plant run by a resort facility" (Fig. 7). The company is also planning for the mega-solar power plant to be used as a site of environmental education by local society. It allowed visits by local elementary school children even during construction.

When constructing the plant, Resorttrust entrusted a firm engaged in resort facility design and construction with the plant design and focused on the plant's appearance with a view to accomplishing long-term reliability and a mega-solar power plant that blends in with local nature. While adopting acclaimed domestic manufacturers' (Panasonic's and TMEIC's) solar panels and PV inverters in view of long-term reliability, the company entrusted the foundation and the mounting system to Yasui Architects & Engineers Inc, which is engaged in hotel construction (Fig. 8).

Resorttrust also boosted construction efficiency by precutting all steel materials of the mounting system at the plant and assembling them on site (Fig. 9). Considering the image of a mega-solar power plant surrounded by trees between mountains, the company selected new utility poles and fence both colored in dark brown (Fig. 10). Being aware that the cost would rise slightly if it persisted with the color, Resorttrust said it paid consideration to a design that would blend in with the surrounding natural environment just like it had done with its hotel.

Resorttrust's mega-solar power plant, which gives consideration to "disaster response in tandem with local society and harmony with nature," demonstrates a number of perspectives unique to a resort facility rooted in the area.