Latest statistics on agrivoltaics installations in Japan

The Ministry of Agriculture, Forestry and Fisheries has released the latest statistics on agrivoltaics/solar sharing in Japan, as of the end of March 2020.

The total number of installations in Japan was 2,653, an increase of 661 over the past year. Since the area is 181.6 ha, it is estimated that about 200 MW of agrivoltaics has been installed. The total amount of power generation equipment is about 800MW.

The number of cases introduced in one year reached a record high, but the rate of increase by prefecture varied greatly.

The following table shows the number of solar sharing installations by prefecture according to the MAFF Japan.

In terms of geographical distribution, there is a clear difference between east and west, with the eastern part of Japan, especially the Kanto region, being the most popular. On the other hand, in the Hokuriku region, Kansai region, and Kyushu region, the introduction is not so advanced.

This is presumably due to differences in values about agriculture, the influence of local governments' agricultural policies, sunshine hours, and other factors.

In addition, the Kyushu region, where the introduction of solar power generation was flourishing when the FIT was first introduced, is also thought to have been adversely affected by the curtailment of solar power output by Kyushu Electric Power.

In some areas, such as Miyagi and Tochigi prefectures, we have seen a rapid increase in the number of installations, but this is likely due to the fact that certain businesses are focusing on solar sharing for development.

In the future, we will further investigate the trends in each region to clarify the actual situation.

Standard Design for Agrivoltaics in Japan

Fujidana style and array designs are the most common types of solar sharing in Japan. In the case of the Fujidata style, which can equalize the amount of solar radiation to crops, a shading ratio of about 40% can be considered as a standard design.

Fujidata style in Japan

The number of solar panels that can be installed with a shading ratio of 40% is about 1,800 per hectare of farmland.

As of 2021, solar panels with an output of around 450W are the mainstream, so 810kWp is the output of solar power generation.

Depending on the region where it is installed, it can be expected to generate 900,000 to 1,000,000 kWh of electricity per year.

Since the current unit price for electricity sales under Japan's FIT is 11 yen/kWh, we estimate that the annual income from electricity sales will be between 10 million yen and 11 million yen.

On the other hand, the annual sales of crops in a paddy field of the same size will be about 1 million yen, while in a field it will be 3 to 5 million yen.

Working with tractors

The distance between the pillars should be about 4 to 5 meters, and the overall height of the facility is designed to be about 4 meters. By doing so, we aim to secure the working space for agricultural machinery and solar radiation from scattered light.

Leafy Vegetables and Agrivoltaics

One of the characteristic agricultural products grown under agrivoltaics is leafy vegetables such as cabbage and lettuce. 

Since they are easily affected by strong sunlight, shading with solar panels will help the growth of leafy vegetables.

Growing Cabbage and Lettuce

In the lowlands of Japan, summers are too hot for growing leafy vegetables. However, solar sharing makes it possible to grow leafy vegetables by blocking the strong summer sunlight.

Another known benefit of the presence of solar panels is that they help to control frost in winter. Therefore, in areas where leafy vegetables could not be grown in the winter, it has become possible to grow cabbage and other crops through solar sharing.

Of course, it's not just good for leafy greens. Shading by solar panels delays the drying of the ground after rain. This can lead to disease outbreaks due to moisture damage.

Nevertheless, the advantage of being able to grow vegetables that could not be grown within the region before will bring about a very significant change.

The Japanese Government's New Basic Energy Plan and Agrivoltaics

Currently, the Japanese government is formulating a new mid-term plan for energy policy. This plan includes a target for the introduction of renewable energy in 2030, and the figures are attracting attention.

The draft of the plan was released on July 21, and in it, the target for Japan's introduction of renewable energy in 2030 was presented as 36% to 38%. Other than renewable energy, nuclear power accounts for 20% to 22%, and thermal power accounts for about 41%.

Unfortunately, this is not an ambitious goal at all, but given Japan's lagging status in the international community, it is a figure that will require a great deal of effort to achieve.

Among renewable energies, there is no other option but to greatly increase solar power, but here again, unfortunately, the target was not ambitious enough to introduce it. The figures remain very ambiguous.

The Japanese government did not adopt the private sector's proposal that two to three times the amount of solar power generation equipment will be needed compared to 2020. In this draft, the introduction target is stuck at 100 GW.

The reason for this was the reluctance to include farmland in the piling up of numbers on where to build more solar power plants.

However, additional 50 GW to 100 GW can easily be introduced by using agrivoltaics, and more steps should be taken to promote renewable energy that coexists with agriculture.

How to Choose PV modules for Agrivoltaics in Japan

Agrivoltaics in Japan has involved a unique selection process for PV modules. Slim PV modules were favored when they were first popularized in 2013. The purpose of this was to ensure that solar radiation would hit crops as evenly as possible and to prevent damage to equipment from strong winds.

Fujidana style solar sharing with slim PV modules

At the time, Japan's high cost of FIT made it possible to use these specially designed solar panels. By adopting the slim type, the project cost will be 30% to 50% higher than that of ordinary industrial solar panels.

This is limited to the Fujidana style solar sharing design, while the array type design uses larger products from the beginning.

Since around 2017, normal, larger products have gradually come into use, partly due to changes in the market, such as the need to improve business viability as a result of lowered FITs and the withdrawal of manufacturers producing slim types.

Fujidana style solar sharing with large modules

The latest design of the Fujidana style solar sharing minimizes the impact on growth through precise simulation of solar radiation on crops. Improvements in design have also made it possible to withstand large typhoons. As a result, the need to adopt slim-type products is now decreasing.

In the future, research is being conducted on the use of double-sided glass solar panels to improve durability and increase solar radiation while also ensuring economic efficiency.

Increase in agricultural participation triggered by Agrivoltaics

The spread of agrivoltaics has encouraged new entrants to agriculture in Japan.

As of 2020, the agricultural population in Japan has declined to one-tenth of what it was 60 years ago. The average age of farmers has reached 67, so we need to increase the number of young people entering the industry.

Strangely enough, more and more young people and businesses in Japan are taking advantage of agrivoltaics to enter the agricultural industry.

Young people in their twenties are moving toward agriculture

Currently, solar power companies in Japan are actively engaged in agrivoltaics. It is not uncommon for businesses that have been involved in the solar power business to enter the agriculture industry by getting involved in agrivoltaics.

It seems that this experience with renewable energy has sparked an interest in agriculture.

So why is the younger generation interested in this? It is probably because they have a stronger interest in energy and agricultural sustainability.

The income from energy makes it easier to engage in agriculture. And there is a growing trend to use renewable energy in agriculture, rather than simply selling electricity.

The time will soon come when solar sharing will be the common choice for newcomers to agriculture.

Design Patterns for Agrivoltaics in Japan

The design of Agrivoltaics or solar-sharing systems in Japan has changed significantly since the start of their widespread use in 2013.

The concept of the project was divided into two main categories: prioritizing agriculture and prioritizing the power generation business. The decision has been made to prioritize reasonable profits from power generation projects in the face of severe cost tightening by Japan's FIT, or to pursue designs that are more suitable for farming and crops.

The one that has been prioritizing the profitability of the power generation business is a design known as the Array type. This is simply a taller pillar of the racks used in ordinary ground-mounted solar power plants.

Array type solar-sharing

In the case of the array system, it can be installed at a cost not much different from that of a ground-mounted solar power plant, but the shading rate may be uneven and agricultural machinery may be difficult to use.

In contrast, the Fujidana style design, in which solar panels are installed evenly, has been actively adopted. This design has been adopted with the idea of prioritizing farm work and agricultural production.

Early Fujidana style solar-sharing

In the early stages of the widespread use of solar sharing, the use of slim solar panels was favored in addition to this uniform solar panel design. However, this custom-made solar panel has become less common in recent years due to the increasing difficulty in obtaining them.

For the past three years or so, there has been an increase in the use of Fujidana style mounts with large solar panels as a design that allows for both farming and power generation projects.

The latest model of Fujidana style solar-sharing