A farming-style solar power plant with an output of about 900kW is located in a corner of an agricultural area in Kumamoto City (Fig. 1). Solar panels were spaced apart from each other and set up on farmland, so farm products and power generation could share the sunlight. Such a structure is generally called "solar sharing."

Fig. 1: The farming-style Nakamura Solar Power Plant located in a farming area of Kumamoto City (source: Kyudenko)

This plant's power producer is a part-time farming family and a married couple who do the farm work together. The plant is named "Nakamura Solar Power Plant" after the couple's family name.

The farming-style solar power generation system adopted at the Nakamura Solar Power Plant appears to have more robust foundations and mounting systems compared with other general farming-style systems seen in Japan. The plant adopted this system with the aim of keeping costs as low as possible while fulfilling requirements for toughness to realize reliability over 20 years and agricultural efficiency to not interfere with tractor mobility.

Kyudenko Corp provided engineering, procurement and construction (EPC) services. Kyudenko is also responsible for operation and maintenance (O&M) services at this plant. The plant adopted solar panels manufactured by SunPower Corp of the US and PV inverters manufactured by Toshiba Mitsubishi-Electric Industrial Systems Corp (TMEIC).

Three years have passed since the plant started selling power in October 2014. I visited the plant to check on its progress after it was covered in this section in the summer of 2015 (See related article).

The solar power generation business has been favorable, continuing to sell power worth about 5.8 million yen (approx US$51,146) per month.

"Compared with agriculture, I appreciate the solar power generation business more because it doesn't have such problems as appropriately fertilizing crops and preventing and curing plant diseases," Mr. Nakamura said.

The plant, however, has experienced some problems thus far. First, it was affected by the Kumamoto Earthquakes in April 2016.