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Research & Information

Concept & Synergies

Agrivoltaics is more than the connection of agriculture and solar energy. On this page you will find the underlying concept and the wide range of technical application. Furthermore, we highlight the synergies created by combining agriculture and photovoltaics. Learn more on how this integration can lead to more sustainable production methods.

From Idea to Realization

The idea of using agricultural land for both agricultural production and electricity generation using photovoltaics has been around since the 1980s.

In 1981, the concept was introduced by Prof. Dr. Adolf Goetzberger, founder of the Fraunhofer Institute for Solar Energy Systems ISE, and Dr. Armin Zastrow. The scientists recognized that dual land use could bring great benefits. They investigated how conventional PV systems could be adapted to enable homogeneous plant growth in parallel with solar power generation. A first sketch can be seen opposite.

After the turn of the millennium, the concept of agrivoltaics was put into practice and researched in pilot plants, first in Japan, then in Germany and France. However, it is only in recent years that the implementation of this concept of agrivoltaics has gained momentum and has developed considerably to the large industrial plants that exist today.

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The Technology Behind the Concept

Agrivoltaic systems generate electricity in the same way as conventional photovoltaic systems on roofs or open spaces. However, due to the dual use of space, they place additional demands on the technical components of the modules and the mounting of the system. A basic distinction can be made between open and closed systems. Open agrivoltaic systems are subdivided into elevated systems (mounted under modules) and ground-level systems (mounted between modules). Closed systems are used in PV greenhouses.

From an agricultural perspective, module technologies that allow the light spectra necessary for plant growth to pass through are particularly interesting. These include organic photovoltaics, semi-transparent PV module technologies or the use of tracking systems that can actively control the degree of shading through tracking. More targeted light management can also be achieved by narrowing or deviating from a south to an east or west orientation of the PV module position. Another special type of module is bifacial PV modules, which allow solar power to be generated on the front and back of the PV modules, thereby producing higher energy yields than conventional PV modules. The higher and wider the bifacial modules are installed, the more light can reach the rear side.

The partial roofing of the area also changes the distribution of precipitation. To avoid negative drip edges of the PV modules on soil and plants, precipitation must be taken into account in the system design. Measures such as the use of special PV modules (narrow, tubular) or a complete system approach with integrated rainwater harvesting can be used for this purpose.

The substructure must also be adapted to the agricultural use. The anchoring of the substructure into the soil in particular should not have any negative effects on the soil quality. Anchoring methods such as screw and pile foundations can be considered.

One other area of research by Fraunhofer ISE are the technology and sustainability assessments and life cycle analyses for solar cells.

Agrivoltaics Areas of Application
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Agriculture

Strategies

In a combination of agriculture and energy generation through agrivoltaic systems, the pressure of competition for land can be reduced. In principle, any plant can be cultivated by using agrivoltaics. However, in temperate climate zones, crops that are less sensitive to light (shade plants) are better suited to cultivation in a partially shaded agrivoltaic systems than plants that require a lot of light for optimum growth (sun plants).

As a result of climate change, we are not only seeing global warming, but also an increase in severe weather events worldwide. Agrivoltaic systems can partially or even completely replace agricultural protective structures against the effects of the weather such as hail nets or foils.

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© BayWa

Synergies

The results from the research project in Heggelbach show that the partial shading caused by modules results in a slightly altered microclimate under the modules. This can have a yield-stabilizing effect, especially during periods of drought, as the APV RESOLA research project has shown.

Crops such as berries or apples are often very susceptible to external influences, which is why they can benefit greatly from protective devices such as hail nets or films against the effects of the weather, which can be easily replaced by agrivoltaic systems. See research projects APV-Obstbau or model region Agri-Photovoltaik Baden-Württemberg.

APV-Obstbau (Orcharding) – Agrivoltaics as Resilience Concept for Adaptation to Climate Change in Orcharding
APV-RESOLA – Agrophotovoltaic - A Contribution to Resource-Efficient Land Use
Model Region Agri-PV BaWü

Water Balance

Strategies

Agriculture already consumes around 70 percent of the world's fresh water through irrigation. The areas requiring irrigation have more than doubled since the 1960s. In view of the worsening water shortage in many parts of the world, agriculture needs solutions to save water and use it efficiently. Agrivoltaics offers the possibility of reducing the water requirements of plants through targeted light management and at the same time capturing and storing valuable rainwater.

In order to avoid erosion in agrivoltaic systems, various water management approaches can be used in the system design. Narrow PV modules and targeted drainage of rainwater can prevent the accumulation of large quantities of water under the edge of the module.

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© Fraunhofer ISE

Synergies

If plants are exposed to too much sunlight, their water consumption increases and their photosynthetic performance decreases. By implementing agrivoltaics, solar radiation can be regulated in such a way that plants have the best possible light conditions for their growth and therefore consume less water.

Especially in arid regions, the collection and storage of rainwater can conserve groundwater supplies or make agricultural activities possible in the first place.

The APV-MaGa project is testing a threefold land use for rural regions in West Africa. In this context, rainwater harvesting and storage are being investigated in addition to the dual land use of agriculture and PV.

APV-MaGa – Agrivoltaics for Mali and Gambia: Sustainable Electricity Production by Integrated Food, Energy and Water Systems

Society

Strategies

The expansion of renewable energies can exacerbate regional land use competition and lead to social controversy and resistance. Successful public participation concepts are needed to strengthen the social acceptance of agrivoltaics. So that this can be achieved, Fraunhofer ISE has developed a number of factors for the successful introduction of agrivoltaics:

  1. Give preference to local farms, energy cooperatives or regional investors for the construction and operation of agrivoltaic systems.
  2. Limit the size and distribution of installations and define them taking into account local site characteristics and social preferences.
  3. Obligation to produce food under agrivoltaic systems.
  4. Set up agrivoltaic systems in locations where the dual use of the land increases agricultural yields and protects crops.
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Synergies

Agriculture and energy generation are much-discussed topics among the public. Agrivoltaics enables efficient land use and can therefore reduce land use conflicts, additionally protect the harvest from extreme weather conditions and also diversify the farms' income through self-consumption and the sale of solar power.

On the one hand, the involvement of small and medium-sized enterprises in the construction and development of agrivoltaic systems increases local value creation, while on the other, the involvement of the local population leads to greater social acceptance of renewable energies in the long term.

In order to promote acceptance of agrivotaics in general, it is essential to involve various interest groups at an early stage. In this way, preferences and fears can be adequately taken into account and potential conflicts identified at an early stage. On the basis of this dialog, a common vision for the energy transition and regional food production can be developed.

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