Japanese engineers built an impressive solar plant on top of a former landfill site, despite the numerous challenges associated with harsh and very snowy winters, limited amount of incoming light and instability created by the tons of garbage underneath.
The unique power plant with an output of 1.5MW, was constructed and will be maintained by JFE Engineering and Sejimo Construction. It opened its doors in Akita City, Japan, on 1st of October.
It is commonly believed that when a solar power plant is to be constructed, most conditions that ensure maximum light conversion should be present, simply because of the high initial cost associated with installation. Investors are rarely keen to put their money on a facility, which will be built on a shady landfill site, covered by snow for most of the winter season. But people do incredible things when they have the will to stimulate local enterprises and boost regional economy, and the General Environment Center in Akita demonstrated that.
Situated in the northern part of the main island of Japan, Akita is definitely not the most suitable place for solar energy production, due to very little sunshine that it receives and the undesirable weather conditions. However, the members of the city’s Municipal Government were not scared of this and what was more, they were determined to convert the 4.6 ha of local former landfill site into a renewable energy generating facility.
To fund and construct the facility, the local government decided to implement the leasing method, which essentially means that they run the facility, while the power generation systems are owned by a leasing company. The Century Tokyo Leasing Corp (TCL), JFE Engineering Corp and Sejimo Construction, presented the best offer for construction, maintenance and power generation.
In order to ensure annual power supply of 1.75 million kWh in an area with limited sunshine, the plant was equipped with solar panels of up to 2.2MW output, which was more than the capacity of the PV inverters. The power, which exceeds this capacity will be lost, however, in this way the facility will maintain sufficient amount of power generation when the sun is weak.
The problem with snow cover, the engineers solved by tilting the panels at 30 degrees, and the lowest height of the panels was put up to 1.5m. Although this makes the shadows longer in the morning and in the afternoon, it ensures that the snow does not accumulate. The panels are arranged in such way that even if the lowest row is completely shaded, the upper side will continue generating power.
And to handle the remaining problem, that of the unstable ground due to the underlying landfill site, the sloping areas were equipped with a tripod-type mounting system. This consists of pipes that are driven up to 2m into the ground at an angle of 40 to 45 degrees, and fitted with supporting posts for the panels. This ensures that the facility can resist any pulling velocity of wind.
This is surely a way to make use of abandoned landfill sites.