Landfill Site Transformed Into Clean Power Plant
Unique efforts to overcome little sun, snow cover
Solar panels and PV inverter. The polycrystalline silicon solar cells were manufactured by Hanwha of Korea and PV inverters by Toshiba Mitsubishi-Electric Industrial Systems (TMEIC). (source: Nikkei BP)
Akita City is one of the heaviest snow zones in Japan. In winter, it has many cloudy days with little sunshine. In fact, it is very close to the bottom in the prefectural ranking for the amount of solar irradiation in Japan. There is even the fear that solar panels could be covered with snow.
The large-scale solar power plant Akita City constructed within the city was confronted by those meteorological drawbacks as well as the restrictions on land reclamation of landfill sites. Efforts are being made to conquer the "triple difficulty" of little sunshine, snow cover and a former landfill site and ensure adequate commercial returns.
Challenging construction in region ill-suited to PV power
The Akita City General Environment Center is a facility that accepts domestic waste from residents of Akita City. It incinerates and melts up to 460t of waste per day, reusing it in various ways such as slag.
Before the gasification melting furnace was introduced about ten years ago, the center burnt combustible waste in the incinerator and buried the incinerated ash and incombustible waste in the adjoining landfill site. After they are filled up, landfill sites are covered with soil and abandoned. Given the limited use of such sites, this site became a field of weeds.
On Oct 1, 2013, a 1.5MW solar power plant was completed and started power generation in an approximately 4.6ha idle site. As you pass through the facility's gate, a huge box-like building, which is the gasification melting furnace, can be seen up ahead.
Coming into view as you walk around to the building's rear side, with the adjoining recycling facility on your left, are the solar panels neatly arrayed across the gently sloping hill. The 9,170 1.6 x 1m polycrystalline silicon solar panels, tilted at 30° on the mounting systems, look like a modern art object made of huge plates with a navy and white striped pattern.
"Akita City is an ill-suited region for solar power generation because of the little sunshine it enjoys," said Masaaki Nasu, Global Warming Deputy Director, Environmental General Affairs Division, Environment Department, Akita City Municipal Government. "Moreover, former landfill sites have another issue: ground condition. Nevertheless, we boldly decided to construct a large-scale solar power plant following the implementation of the feed-in tariff (FIT) program."
"To energize the regional economy, we wanted local enterprises to be deeply involved with the solar power plant's construction and operation," he said. "To make it happen, we wanted to enhance our influence by producing power by ourselves, instead of just leasing land to power plants. However, it was difficult for Akita City to provide or raise the funds for initial investment in the solar power plant."
What Akita City decided upon after discussions by the municipal government was a lease method. The predecessor for this method was Ota City, Gunma Prefecture. In Ota City, the municipal government runs a power plant while Century Tokyo Leasing Corp (TCL) owns the solar power generation system facilities in the plant.
What differed from other conventional facility leases was the lease fee, which includes not only the construction cost but also regular inspection, maintenance and repair costs that would come about in accordance with the power plant's operation as well as the cost to purchase fire and other insurance policies. TCL calls contracts based on such a method "comprehensive facility lease contracts."
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