AGROVOLTAICS

Agrovoltaic energy, when agriculture and renewables go hand in hand

#environmental sustainability #R&D #renewable energy

Agrovoltaics, which seeks maximum synergy between photovoltaic energy and agriculture by installing solar panels on farmland, is positioning itself as one of the benchmarks for making a sector that does not want to be left behind in the fight against climate change more sustainable. Below, we discuss its impact, as well as its characteristics and advantages.

Climate change is the greatest threat hanging over humanity's future. The consumption of fossil fuels and activities linked to the agricultural sector are two of the biggest contributors to climate change because they emit greenhouse gases, which cause global warming. If the solution lies in renewable energy and sustainable agriculture, then why not combine the two? This exactly what agrovoltaics is all about.

WHAT IS AGROVOLTAIC ENERGY

Agrovoltaic energy, also known as agrophotovoltaics, consists of using the same area of land to obtain both solar energy and agricultural products. In other words, solar panels coexist with crops on the same surface. This technique was originally conceived by Adolf Goetzberger and Armin Zastrow in 1981, but the concept did not become popular until just last decade.

The shade from the panels cast on crops can affect their productivity, since they receive slightly less light — although this can benefit certain crops — but energy production compensates for this loss. According to a study published by Nature, if just 1 % of arable land were dedicated to produce solar energy, it would be possible to offset the world's energy demand.

The use of solar energy in agricultural areas also encourages photovoltaic self-consumption, since farms' energy needs can easily be met with the electricity generated. Agrovoltaics also has close links with smart farming, which improves productivity through technology like artificial intelligence, big data and the Internet of Things. In turn, it drives the development of smart villages.
 

HOW DOES AGROVOLTAICS WORK

Generally, fixed support systems are used to elevate the solar panels about five metres above crop field. This allows farm machinery access to the crops below. Solar panels can also be installed on greenhouse roofs. Another solution is dynamic agrovoltaics, which involves installing the panels on elevated cables — a lighter alternative that is easy to disassemble — and allows the panels to be moved or adjusted manually over the seasons and as the farmer cultivates different plots of land.

Other installations have monitoring systems, which allow the panels to be orientated to maximise their efficiency and prevent them from always casting shade in the same place, thus adapting to the needs of the plants. These systems require complex software models that take things like crop growth phases and the weather into account. In the future, solar panels will be developed using semi-transparent polymers that allow the wavelengths of sunlight needed for photosynthesis to pass through and absorb the rest to generate energy.

ADVANTAGES AND DISADVANTAGES OF AGROVOLTAIC ENERGY

When it comes to the environment, the main benefit of agrovoltaics is that it reduces greenhouse gas emissions from the agricultural sector. What's more, the dual use of land for both agriculture and for energy relieves pressure on ecosystems and biodiversity, which are affected when cultivation areas are expanded.

Studies estimate that the electricity generated by solar panels increases the economic value of agrovoltaic farms by more than 30 %, as it improves land-use efficiency and yields, as can be seen in the infographic. This is especially true in warmer areas, where the shade can protect crops by reducing temperatures and preventing excessive evaporation.
 

The efficiency of agrovoltaics.#RRSSThe efficiency of agrovoltaics.

 SEE INFOGRAPHIC: The efficiency of agrovoltaics [PDF]

As we have already mentioned, the main disadvantages of this energy source stem from the shade cast by the panels, as this can affect crop productivity to varying degrees, forcing more resistant plants to be chosen and restricting those that are more dependent on sunlight. This also limits the latitudes where agrovoltaics work best, as in cooler areas, where sunlight intensity levels vary throughout the year, profitability can suffer. Other things to take into consideration are the high initial investment required — although this may fall as agrovoltaics takes hold — and the impact on the landscape.

APPLICATIONS OF AGROVOLTAICS

Agrovoltaics has many different applications depending on the environment and the intended use of the installations. Below, we review some of them:

 Electricity production and crops

Solar panels share the same land as fruit, vegetables and cereals, which they protect from the atmospheric phenomena. This is the most common modality.

 Electricity production and grazing

On non-arable land, or where the climate is less suitable for growing crops, the ground beneath the solar panels can be used for livestock grazing.

 Electricity production, fresh water and crops

Three-in-one use suited to coastal areas. The electricity generated is used to power a desalination plant that produces water for the crops and for human consumption.