Efforts to replace fossil fuels with natural energy have been ongoing since greenhouse gases were identified as the main culprit behind global warming. Amid growing interest in renewable energy due to the 'Green New Deal' policy that recently led to an energy transition, agrivoltaics, which allows farming and production of electricity to take place at the same time, is drawing growing attention as another leading solution to tackling climate change.
Farming and generating solar energy at the same time!
Agrivoltaics refers to the technique of producing solar energy above farmland and growing crops under the solar panels at the same time. In other words, it is a system that can produce renewable energy while maintaining the agriculture output of fields, rice paddies, orchards, etc., which is the main purpose of farmlands. Moreover, agrivoltaics consists of panels installed with a 3.5-m ground clearance, allowing even large agricultural machinery, such as rice-planting machines and combines, to pass freely underneath the solar panels.
When an agrivoltaic system is introduced, at least 80% of farmland yield can be maintained and additional income can be earned through the production of electricity. According to the results of the test operation of an agrivoltaic facility in 2020 by Jeonnam Agricultural Research Center, when the agrivoltaic system was used, about 5 times* as much profit was earned compared to when rice was produced separately, excluding incidental expenses.
* Based on 100kW-class agrivoltaic facility and 1,983 sq. meters of rice farming area (Source: Jeonnam Agricultural Research Center)
Furthermore, the system can help to efficiently utilize the land, increase farm income, and reduce carbon emissions since it makes use of the existing farmland. However, it is fair to wonder: how is generating solar energy possible while farming? It leads us to ask whether the shade created by the solar panels has an impact on farming.
The answer to this question can be easily understood through the concept of ‘light saturation point.’ Crops generate energy from the sun through photosynthesis. As light intensity increases, the rate of photosynthesis also increases. However, once the light intensity reaches a certain level, the rate of photosynthesis does not rise anymore. This point where the light intensity does not increase the photosynthesis rate is called the light saturation point. The light saturation point differs with the type of crop. For instance, rice requires about 5 hours of light exposure per day at a light intensity of 50 Klux. Additional light exposure does not affect photosynthesis, which is why more sunlight does not help the crop grow. Taking these characteristics into consideration, it is essential for agrivoltaics to adjust the size and placement of solar modules to generate electricity while maintaining a sufficient amount of sunlight for growing crops.
<Light saturation point of major crops. Source: Korea South-East Power Co.>
Agrivoltaics is gaining worldwide attention
For agrivoltaics, it is of paramount importance to establish a system suitable for each country’s environment, because each country has unique farming patterns and cultivated crops.
In Europe, research on maximizing crop productivity is being conducted, focusing on Germany and France. France, as a world-class wine producer, is actively engaging in vine growing in line with agrivoltaics. In Lyon, France, research is being conducted on an agrivoltaics system that can cope with bouts of extreme heat. In regions where heat waves are intense, solar modules are adjusted to intentionally create shade for grapevines in the afternoon when solar radiation is high. This lowers the stress on grapes caused by the scorching heat, thereby controlling fruit cracking as well as the sugar content of the fruit.
Germany was the first country to establish the concept of agrivoltaics. Since Germany began researching agrivoltaics in 2011, it has been working on the development of the technology in numerous countries around the world, including Chile, Vietnam, and India. Germany’s agrivoltaics research is focused on land efficiency and expansion of renewable energy. The Fraunhofer Institute, Germany’s leading research organization for applied science, said it aims to contribute to solutions to problems related to food, climate change and energy with the technology.
< An agrivoltaic farm in Heggelbach in the Lake Constance region, Germany, Source: Fraunhofer Group website>
Countries around the globe are continuing efforts for agrivoltaics. In Japan, about 1,300 small agricultural photovoltaic systems were approved from 2013 to 2018, and China created a 1GW agrivoltaic complex in the eastern Yellow River basin.
Agrivoltaics is in the spotlight for its efficient use of land and for in the development of measures to produce renewable energy in Korea, a country with a small land area. According to the Korea Agrivoltaic Association, a total of 16 cases of agrivoltaics verification experiments were reported between 2016 and 2019. Although it is still in the early stages compared to Europe, Japan, and China, Korea’s moves for development of the agrivoltaics industry are in full swing, with the Ministry of Trade, Industry and Energy investing about 21.3 billion won more in urban and agro-photovoltaic (agrivoltaic) facilities this year compared to the previous year.
Q CELLS’ efforts to make agricultural photovoltaics widely available
<A rice planting event held by Q CELLS on a test site for agrivoltaics >
As of 2019, the total area of arable land in Korea was 1.6 million hectares. Therefore, installing agrivoltaic systems using 5% of the area can produce 32 GW of electricity annually, which is equivalent to the annual average electricity consumption of 9.17 million households and around 130% of the government’s goal to install new PV and wind farms by 2025.
< Agricultural photovoltaics farmland fostered by Q CELLS in Gwandang village in Namhae>
One of the key factors to consider for agrivoltaic solar panel installation is to produce electricity while maintaining an adequate amount of sunlight for growing crops. Q CELLS developed a compact PV module, half the size of a traditional PV module, to secure farming solar installations that generate electricity while maintaining adequate sunlight for growing crops.
In addition, Q CELLS recently created an agrivoltatic test site in Namhae, Gyeongsangnam-do, to verify the potential utility of agrivoltaics. The company has also been selected as a joint research partner by the Korean government for the “Agrivoltaic System Standardization Project, to conduct a study to establish agrivoltaic systems localized for rice paddies, farm fields and orchards in Korea.
There still are some challenges to address in order to popularize agrivoltaic systems. Above all, to improve farmers’ acceptance and to secure objective data, including data from verification projects, demonstrating the efficiency of agrivoltaics is highly important. Q CELLS is continuing to raise awareness of the technology and related business so that farmers would accept the solar energy system with higher confidence, while collecting objective data from pilot and test projects.