'Seikan Tunnel' entrance located nearby
The town of Shiriuchicho in the southwest of Oshima Peninsula, Hokkaido, Japan, across which spreads flat land, faces the Tsugaru Strait to the east and mountains in the other three directions. With the entrance to the "Seikan Tunnel" located in the town, the passengers on the Hokkaido Shinkansen (bullet train) will see the abundant nature of Shiriuchicho as soon as the train comes out of the tunnel running under the strait (Fig. 1 & 2).
On August 1, 2019, the "Shiriuchi 20M Mega Solar Power Plant," a mega- (large-scale) solar power plant with an output of 24MW, began operation in Yunosato District of the town where the entrance to the Seikan Tunnel is located. The completion ceremony took place on August 29 with many participants from the power producer, constructor and local communities including Shiriuchicho.
The power producer is GK Hayate Solar, a special purpose company (SPC) established and financed 60% by Orix Corp and 40% by Solar Frontier KK. This SPC rents the project site owned by Shiriuchicho and runs the power generation business. The solar power and PV inverter (grid) capacities reach about 24MW and 17.5MW, respectively. In addition, a storage battery system with an output of 12.5MW and a capacity of 7.2MWh is also installed in this plant.
Toshiba Plant Systems & Services Corp provided engineering, procurement and construction (EPC) services and adopted solar panels of Solar Frontier and inverters manufactured by Toshiba Mitsubishi-Electric Industrial Systems Corp (TMEIC) for both the photovoltaic (PV) power generation and battery systems (Fig. 3).
The Shiriuchi 20M Mega Solar Power Plant faced two major barriers before it was finally completed. First, it needed to convert the project site from Category 1 farmland in order to run the power generation business on it. Second, the plant had to install a storage battery system as a measure against short-period fluctuations ahead of connection with the grid of Hokkaido Electric Power Co Inc (Hokuden).
Converting Category 1 farmland to run a solar power generation business is not normally accepted. Furthermore, even under the feed-in tariff (FIT) scheme, setting up a storage battery system in parallel with a PV system increases initial investment and makes it difficult to secure a certain return on investment.
How did Shiriuchicho and the power producer overcome these tough barriers?