Agrivoltaics for broccoli, cabbage

Image: Chonnam National University

Scientists in South Korea have combined PV generation with vegetable farming and have found that solar array shading provides favorable results for crops such as broccoli and cabbage.

From pv magazine

A research team at Chonnam National University in South Korea has looked at how solar power generation could be combined with broccoli and cabbage cultivation. The team found that the shading provided by a PV facility could improve the quality of crops.

Broccoli and cabbage need to be grown in places that receive full sun, which means between six and eight hours of sunlight per day, or very light shade. A lack of sunlight could result in thin, leggy plants.

“Because of its low light saturation points, broccoli may be a suitable crop to maximize famer’s profits and energy security through an agrivoltaic system,” the scientists said. “However, to date, there is limited information on the performance of brassica crops in agrivoltaics.”

The scientists built their agrivoltaic system with bifacial modules at a height of 3.3 meters. They achieved an average power generation per day of 127 kWh during the testing period. They claimed that their approach demonstrated the technical and economic viability of the proposed agrivoltaic solution.

“We found that the taste and the quality of the broccoli were not lower than those of a reference field without the solar array,” they said. “We also found no significant change in functional ingredients and metabolites that affect taste.”

The PV installation caused a significant reduction in the light hitting the crops, which in turn resulted in an improvement of their color.

“The color of broccoli is an important property that goes beyond appearance quality and is involved in consumers’ desire to purchase,” the scientists said.

They said that presence of the PV system reduced the agricultural yield by around 20%, compared to the reference field without solar. However, they said that the income generated by the solar array could more than compensate for such losses.

“The annual economic benefit from solar power was 10.4 times more than the broccoli production benefits,” the scientists said. “Therefore, farmer benefits will increase as they are cultivated in agrivoltaics compared to open field.”

The researchers presented their findings in “Agrivoltaic Systems Enhance Farmers’ Profits through Broccoli Visual Quality and Electricity Production,” which was recently published in Agronomy.

“In terms of land use efficiency, agrivoltaic is a good means of producing energy and food in Korea, which is a highly mountainous area,” they said.

Author: Emiliano Bellini

Mobile agrivoltaic system from the Netherlands

The mobile agrivoltaic array. Image: h2arvester

Created by a Dutch group of companies and research institutions, the mobile solar system may also be combined with an electrolyzer for hydrogen generation. Two prototypes are currently being tested by a farmer and a research institute in the Netherlands.

From pv magazine

A Dutch consortium has developed a mobile agrivoltaic system that is claimed to improve soil quality and biodiversity of agricultural fields.

Called H2arvester, the first prototype has been deployed on sugar beet land in Oude-Tonge, South Holland, and was inaugurated last week by Netherlands’ Agriculture Minister, Henk Staghouwer.

“The solar car concept was developed four years ago by my company and two other partners,” Marcel Vroom, the owner of design services provider Npk design, told pv magazine. The other two companies are L’orèl Consultancy and LTO Noord. “At the moment, there are two pilots being tested, the one in Oude-Tonge and one in Lelystad, at the research farm of the Wageningen University. Both systems will be operating for one year to test the effect on the yield and the land, to show that there will be no loss of agricultural production.”

Each car measures 12×6 m and is able to move slowly, at a pace of 10 meters per hour, and, during harvesting, it can be moved to the side. According to its developer, the system should cover up to 10% of an agricultural field, which would thus not lose its agricultural purpose. “They are movable arrays of solar panels, assembled on lightweight structures and supported on wheels, moving in pre-defined directions,” Vroom further explained.

The system could also be combined with an electrolyzer to produce hydrogen, which could then be used as a green fuel for agricultural applications. Residual heat coming from hydrogen generation may also be used to dry crops, such as oats, grass and alfalfa.”The solution to convert the generated kWh directly into hydrogen not only provides an autonomous production plant, but is also a solution to the need to balance the production and use of generated energy without worrying about reinforcements of the electricity network,” said Robert Jacobs, energy specialist at L’orèl Consultancy.

The project is part of the H2GO Program, which is an innovation program supporting the combination of electricity and green hydrogen. Partners of the projects are Kitepower, Npk design, L’orèl Consultancy, Rho, Accenda and TU Delft, among others. According to its creators, H2arvester is a circular energy model for a local and regional economy.

The local farmer Jacob Jan Dogterom invested €166,000 in the system located in Oude-Tonge, which consists of four solar cars hosting a total of 168 solar panels and an irrigation system that can also provide water to the surrounding area. “It is a pilot project, the investment is far from being complete. We will continue to build it and if we can develop this on a mass scale, it will only become cheaper,” the consortium said.

InnovationQuarter, the regional economic development agency for the Province of Zuid-Holland, subsidized around half of the project’s costs.

Author: Emiliano Bellini