TESS Engineering commissioned a 2MWAC/3MWDC rooftop solar plant at CREDO Shiga Ryuo in August 2025, and began supplying its output to the logistics facility under a 20-year on-site PPA with surplus sold under the feed-in-premium (FIP) scheme, its parent TESS Holdings announced on September 2, 2025.
According to the statement, the company installed 5,060 590W Jinko Solar panels at the CREDO Asset Management-operated property in Ryuo Town, Shiga Prefecture. It expects the power plant to generate about 3.51GWh annually. Approximately 1.15GWh will be consumed on site and 2.36GWh sold into the wholesale market, with TESS Engineering acting as the aggregator.
The on-site portion is expected to cover about 54% of the facility’s annual power consumption.
TESS Engineering certified the project under FIP in FY2024 when rooftop solar projects were offered 12 yen per kWh for 20 years.
To date, the company has commissioned over 50 solar plants totaling more than 60MW under on-site PPAs. It has been increasingly active in signing larger-scale deals, such as 13.4MW of rooftop solar at DMG Mori’s Iga Campus and planned 20MW of ground-mounted solar on unutilized land at Toyo Tanso’s Takuma Division.
Since October 2023, the government has provided preferential treatment to rooftop solar under the feed-in-tariff (FIT) and FIP schemes compared to ground-mounted installations, exempting them from the auction system and offering higher rates. It will also introduce a scheme frontloading payments in contracts’ early years to shorten payback periods (covered in detail in the February 2025 issue of The Japan Power Industry Executive).
