Public-private Solar Plant Energizes Agriculture in Kumamoto
1MW of panels set up in farming zone
Koshi City in northern Kumamoto Prefecture, Japan, has recently seen a population increase after a new urban area was developed as a commuter suburb of Kumamoto City. The area also boasts agriculture and stock farming in its northern area where the ground is covered by humus soil called "Andosol," volcanic ash deposits from Mount Aso.
The southern side of the Koshi River, in particular, is one of the prefecture's largest breadbaskets boasting huge areas of farmland. The "Koshi Agricultural Energy Project Solar Power Plant," a mega- (large-scale) solar power plant with an output of about 1MW, is located in an area surrounded by rice and vegetable fields (Fig. 1).
The power plant began operation in March 2014 and sells generated power at 36 yen/kWh using the feed-in tariff (FIT) scheme. A total of 3,920 solar panels manufactured by Canadian Solar Inc were set up on simple one-legged pile foundations in a north-south direction. Foundations and mounting systems manufactured by Schletter GmbH of Germany and PV inverters of Toshiba Mitsubishi-Electric Industrial Systems Corp (TMEIC) were adopted.
Leveraging the designing knowhow of juwi Inc of Germany, which is a global, highly experienced engineering, procurement and construction (EPC) service provider for mega-solar plants, this mega-solar plant was constructed after careful preliminary studies of soil bearing capacity and other elements. During the five and a half years since the operation began, the solar plant has reportedly been operating soundly, despite experiencing strong typhoons and earthquakes (Fig. 2).
Partly because of the agriculture and stock farming prospering around the plant, however, the panel surfaces reportedly grew quite dirty. Accordingly, all the solar panels were cleaned in October 2018. The cleaning was carried out in expectation of cost-effectiveness because the amount of power generation increased about 5% as a result of a preliminary test cleaning of some panels. The panel surfaces were washed with soft mops using water carried into the site in tanks (Fig. 3).
Comprehensive partnership with Koshi City
The power producer is Koshi Agricultural Project GK, a special purpose company (SPC) funded by Kumamoto Flour Milling Co Ltd (Kumamoto City) and Shizen Energy Farm Inc (Nishino-omote City, Kagoshima Prefecture) of the Shizen Energy Inc (Fukuoka City) Group engaged in the renewable energy business, and Koshi City.
These funding stakeholders are related to the "Koshi Agricultural Energy Project," which is also used in the power plant's name.
This project started when Shizen Energy and Koshi City signed a comprehensive partnership agreement and began to discuss renewable energy adoption and a structure to return some of its income from power sales back to the local community.
As the plan to construct a mega-solar plant on an idle site in the city and use part of the income from power sales for energizing agriculture was selected as an interest-free loan project of the "Projects on Early Establishment of a Renewable Energy Model that Contributes to Local Communities" conducted by the Ministry of Agriculture, Forestry and Fisheries (MAFF), the project led by the SPC of the three entities started moving ahead (Fig. 4).
To be more specific, some of the revenue from the mega-solar plant is used to support two types of agricultural promotion projects dubbed "protective agriculture" and "aggressive agriculture," respectively.
In the "protective agriculture," 5% of the income from power selling by Koshi Agricultural Energy Project GK, the SPC that runs the mega-solar plant, is donated to the land improvement districts of Koshi and Nishikoshi for the purpose of establishing and improving drains and other agricultural infrastructure. The 5% corresponds to roughly 2,600,000 yen per year.
In the "aggressive agriculture," Shizen Energy Farm, Kumamoto Flour Milling and Koshi City, which fund the SPC, individually donate part of the dividends they receive to Koshi Agricultural Energy Fund and collectively utilize the funds to energize local agriculture (Fig. 5).
Agricultural water facilities constructed
In the aggressive agriculture, every year, the SPC's three stakeholders select a project to support by themselves, exchanging opinions after collecting information about new challenges in the local community. In some cases, they even proactively got involved in and approached the selected projects in tandem. The amount to be granted reportedly totals 5 to 6 million yen (approx US$46,062-55,274) every year.
What agricultural infrastructure will be established in the protective agriculture projects is entrusted to the two land improvement districts. Subsidies have been granted thus far to maintenance and management projects including agricultural water facilities. To be more specific, such projects included weeding/trimming and slope reclamation around a balancing reservoir for flood control, overhaul of diversion decompression valves, and dredging of a semi drainage arterial ditch around the farmland.
Such steady improvement in agricultural infrastructure leads to not only higher agricultural productivity but also has a significant effect on controlling damage from natural disasters amid increasingly extreme weather (Fig. 6 & 7).
'Cold pressed juice' from local vegetables
In regard to the aggressive agriculture, the project has provided support to three major targets: (1) sales channel expansion for local agricultural products, (2) research and development of new technology related to agriculture and stock farming and (3) new farmers.
In the aggressive agriculture, the Koshi Agricultural Energy Project initially approached the development and marketing of "cold pressed juice" using vegetables produced in Koshi City (Fig. 8).
In August 2015, Shizen Energy financed EJ (Bunkyo-ku, Tokyo), which produces, processes and sells agricultural products, to help the company manufacture cold pressed juice and develop delivery stores. "Cold pressed" is the technique to press and extract juice from vegetables and fruits while limiting heat generation. Juice and soup made by this method are characterized by their properties that make it easy to ingest the nutrients and enzymes of the ingredients.
EJ purchased carrots, tomatoes, Japanese leeks, yuzu kosho and so on directly from the producers in Koshi City and sold the products made from these foods at its two stores selling cold pressed juice and soup in Tokyo. In this project, EJ has continued to develop new products since fiscal 2016.
Local specialty 'licorice' used in local beer
What the project approached next was commercializing local beer that uses Koshi City's regional agricultural products. On March 28, 2018, the rollout of the new "Halo Kumamoto Beer" took place at "KAEN," a restaurant in Higashi-ku, Kumamoto City (Fig. 9).
The new beer announced that day used "licorice" which Koshi City cultivates as a flavoring. Licorice is said to have a long history of being used as a medical herb and a sweetener throughout the world. Although "licorice beer" that uses licorice as a flavoring is standard overseas, a product which uses licorice raised in Japan is rare.
This beer is sold in 330ml bottles and has an alcohol content of 6%. It is manufactured at KAEN, the restaurant where the rollout event took place. This restaurant is also a micro-brewery (small-scale beer brewery) equipped with tanks and brewing tools at the back, and roughly 500 bottles of the new beer were manufactured in collaboration with Koshi Agricultural Energy Fund (Fig. 10).
The new beer served for tasting received favorable comments such as "less bitter and tastes refreshing with a hint of licorice left behind after drinking."
Shizen Energy Farm launched its food brand "Halo Japan Food" with the aim of planning and producing, in tandem with farmers, food that leverages agricultural products across Japan where the Shizen Energy Group's renewable energy-based power plants are located. The "Halo Kumamoto Beer" was the first release from the brand (Fig. 11 & 12).
New rice cultivar development supported
Furthermore, the development of a new rice cultivar led by Kumamoto Flour Milling is also being supported as an aggressive agriculture project of the Koshi Agricultural Energy Project.
For example, "WE Rice," which Kyushu University developed and Kumamoto Flour Milling produces in collaboration with farmers in Koshi City, is hard to digest and has a lot of vitamins, helpful in combating diabetes and lifestyle diseases.
When it came to supporting new farmers, the project helped conduct training seminars for enterprises aiming to enter the agricultural industry from other industries as well as the children of farmers who were also interested in agriculture.
Funded by the profits from the mega-solar business, the Koshi Agricultural Energy Project aims to contribute to energizing agriculture by providing sustainable support from multiple directions such as personnel training, agricultural infrastructure and new product development along with "aggressive" and "protective" agriculture.