Sun Agri: Combining Solar Energy and Agriculture

Agrivoltaics, also known as “Sun Agri,” merges solar energy production with agriculture on the same parcel of land. This practice allows for the cultivation of crops or raising of livestock beneath or between rows of solar panels. By producing food and energy simultaneously, this co-location method addresses the competition for land between renewable energy and agriculture.

How Agrivoltaics Works

The physical arrangement of an agrivoltaic system is designed to balance the needs of solar panels and agricultural activity. Solar panels are mounted on elevated structures, high enough for farm machinery to pass and for sunlight to reach the crops below. The height and spacing of these panels are carefully planned based on the specific requirements of the crops being cultivated and the layout of the farm.

Another design involves spacing panels in rows with wider gaps than a conventional solar farm, creating alternating strips of sun and shade. This configuration can be adapted to various types of agriculture, from crop fields to pastures for livestock grazing. Some advanced systems feature dynamic panels that can tilt to control shade, adapting to plant needs and weather conditions.

Dual Benefits of Co-location

Integrating solar panels and agriculture creates a symbiotic relationship. For crops, the partial shade from the panels offers protection from excessive heat and sun exposure. This shading can lower ground surface temperatures by an average of 3°C to 5°C, reducing heat stress on plants. This cooling effect also reduces soil water evaporation, enhancing soil moisture and leading to more efficient water use, a benefit in arid regions.

This arrangement also enhances solar panel performance. Transpiration from plants releases water vapor, creating a cooler microclimate around the panels. This natural cooling improves the efficiency and energy output of the photovoltaic modules, as they operate more effectively at lower temperatures.

From an economic standpoint, agrivoltaics offers landowners a diversified income source. By harvesting both crops and solar energy from the same acreage, farmers supplement their agricultural earnings with revenue from electricity generation. This provides greater financial stability against market fluctuations or variable crop yields, making the land a more productive asset.

Crop Suitability and Selection

The success of an agrivoltaic system depends on selecting appropriate crops that can thrive in a partially shaded environment. Shade-tolerant plants like leafy greens, such as lettuce, kale, and spinach, are well-suited for these conditions. Other crops like peppers, tomatoes, and certain herbs have also demonstrated improved growth. A study in Japan found that strawberries grown in an agrivoltaic system had higher sugar content.

Conversely, not all crops are suitable for cultivation beneath solar panels. Plants that require full, direct sunlight, such as major commodity crops like corn and wheat, may not perform well. Their yield could be negatively impacted by the shade, so careful consideration of a crop’s light requirements is necessary for a successful implementation.

Implementation Challenges

Despite its benefits, agrivoltaics faces practical and economic hurdles. The most significant barrier is the high initial investment required to install the solar infrastructure. The upfront costs for elevated mounting structures and panels can be substantial for many farm operations. Careful financial planning and access to supportive policies are often needed to make a project feasible.

Logistical issues can also arise from integrating solar arrays into an active farm. Maneuvering large farm machinery around panel supports requires careful planning and may necessitate adjustments to farming practices. Another challenge is designing a system that optimizes both energy and crop yield, as a poor layout can lead to excessive shading and reduced agricultural output.