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.

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