There are several challenges for tomorrow’s agriculture
Planting today means planning for 2020 to 2050 and reflecting on strategies to adapt to climate change.
These are the main challenges for sustainable crops with strong economic impact. According to IPCC experts, a mean warming of more than 4°C is to be expected at the surface of the planet for 2100. This scenario would allegedly go hand in hand with extreme climate events such as heat waves, summer droughts and intense winter rains. Natural phenomena are already the causes of several disasters in almost every business sector. The farming sector is more directly impacted. Global warming is becoming one of the biggest challenges for tomorrow’s farming sector.
The potential substantial decrease of farm productivity is alarming
Farming is one of the sectors most directly impacted by global warming:
- Excessive heat on crops damages plants, leaves and fruits,
- Reduction of the quality of products
- Excessive perspiration leading to scarcity of water resources.
Unpredictable weather leads to increasingly complex risks management
In the most affected regions this can create proper economic shocks. For example, during summer droughts, the use of water is at stake. The development of irrigation, which is a must for some crops (flowers, fruits, vegetable) forces territorial authorities to increase public water investments. Sectors concerned require heavy investments in order to be able to operate at a time when they are facing an increasingly fiercer international competition.
The increase of food and energy needs fosters a competition over farmland between farmers and energy producers.
Today, the production of photovoltaic energy is facing major challenges
Promising development objectives…
From an energy point of view, one must also anticipate the consequences of global warming resulting from past and current over emissions. The Act on Energy Transition for Green Growth of July 2015 stipulates that renewable energies will have to represent 40% of the electricity production by 2030. As for the solar sector, Minister Ségolène Royal raised the objective of installed electrical generation to 8,000 MW by 2020 from 5,400 MW originally but which will be reached by 2014. This can be partly explained by a significant reduction of photovoltaic solar installations costs between 2009 and 2015: from 7€/Wc to 1€/Wc.
… but significant constraints for lands: solar photovoltaics being limited to lands where there are no land-use conflict
For ground installations, solar photovoltaic is limited to plots where there are no land-use conflict uses: land unsuitable for building or land unsuitable for crops (quarry, wastelands, flood zones, contaminated zones). The potential of these lands is decreasing due to an increase of projects thus leading to an increase of land rental price. Most lands with high potential are already equipped. Therefore, only expensive lands are left due to the fact that they are far from the grid or are uneven. Thus, photovoltaic electricity needs space which is one of its main characteristics.
The future of solar photovoltaic lies in upgrading secondary uses
Roofs and car parks costs are still very high due to infrastructure or renovation works thus impacting competitiveness. In the context of appropriate surface reduction for ground photovoltaic and of high costs of solutions for roofs or car parks shading, power stations combined with farm activities, and therefore located in the fields, offer unlimited surface potential. There is, however, no chance that the entire French farmland surface be completely covered with dynamic agrivoltaic systems. Indeed, only 0.5% of the 28 million hectares of cultivated land in France would produce as much power as the 58 operating French nuclear reactors.
The optimal solution to combine photovoltaics and farming appear to have not yet been found
Current photovoltaic greenhouses show shade levels between 40 and 80% on an average. These figures clearly indicate that electricity production is a priority.
Unfortunately, most photovoltaic greenhouses today have been designed by photovoltaic installers without first consulting with farmers, which explains why project managers have favoured electricity production over farm production. Therefore, farmers have to deal with a dim tool that is therefore not appropriate for large farmland.
Farming has to adapt to current photovoltaic systems
The reasoning is usually based on established economic advantages i) providing a greenhouse almost free of charge or ii) thanks to the sale of electricity. However farming benefits are usually fictional and not validated by any experiment. The farmer must then adapt his production methods to the photovoltaic greenhouse conditions and must continuously adjust his techniques. However, this may not necessarily be enough to get competitive production both from a quantitative or qualitative point of view.