Sun Forest Co Ltd started operations of a mega-solar (large-scale solar) power plant with an output capacity of 1.3MW in Taka-cho, Hyogo Prefecture, Japan, Jan 31, 2014.
Sun Forest (Kobe City) is funded by Hyogo Prefectural Federations of Forest Owners Cooperative Associations (Kobe City). For the solar plant, "Wooden Mounting System Mega-solar Taka Power Plant," Sun Forest rented a site from Taka-cho and set up solar panels on wooden mounting systems made of thinnings produced in the prefecture.
Sharp Corp supplied solar panels, and NTT Facilities Inc provided EPC (engineering, procurement and construction) services. The total cost of the project is ¥400 million (approx US$3.93 million). For the construction of the wooden parts of the plant, Sun Forest used a subsidy for "Forest and Forestry Emergency Development Projects and Promotion of Introduction of Local Materials for New Applications."
The wooden mounting systems were co-developed by Sun Forest and NTT Facilities. They were built on concrete foundations by using two types of square timbers measuring 105 x 105mm and 105 x 30mm, respectively. The amount of lumber used is about 180m2.
The square timbers were made by precutting cedar thinnings produced in the prefecture and, then, injecting a preservative with pressure into them through an incising process. They have a durability equivalent to the "K4" category (the highest resistance to corrosion) on the Japanese Agricultural Standard.
Moreover, Sun Forest employed a design that prevents wooden parts from being in contact with concrete, which tends to be moist, reducing the risk of corrosion. The wooden parts can be recycled as wooden biomass chips.
Sun Forest and NTT Facilities accumulated knowhow to build wooden mounting systems at Taka Power Plant, and they plan to apply it nationwide. NTT Facilities will design and construct facilities, and Sun Forest will provide knowhow to choose, process and supply lumber to local forestry cooperatives through the National Federation of Forest Owners' Co-operative Association.
The two companies have already received an order for the construction of a 5MW solar power plant that the Enterprise Department of the government of Hyogo Prefecture will build in Nishiharima by using wooden mounting systems.