Photovoltaism, Agriculture and Ecology. Martine Hossaert-McKey
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main studies and summaries presented here on the subject – notably those carried out by ADEME (French Environment and Energy Management Agency) – remind us that the photovoltaic industry can still make progress in reducing its ecological footprint. Three particularly sensitive points are brought to the reader’s attention: the conditions for extracting, processing and transporting silicon, the materials needed to build the installations and the recyclability of the material at the end of its life.
Second, lessons from experience: agrivoltaics and ecovoltaics have been tested in recent years on very different scales and in very different ways. The overview of initiatives carried out in France and abroad integrating these agro- and eco-energy approaches shows one of the major difficulties hindering their deployment: the lack of natural light for the crops protected by the photovoltaic panels.
Lastly, and most importantly, in response to these difficulties, solutions are outlined and tested in the field, in particular the cultivation of plants chosen specifically for their tolerance of low soil moisture and their food, medicinal, phytosanitary and ecological value. The first results obtained for these crops are encouraging; they are intended to provide food for thought on the future of our agricultural models.
Thomas LESUEUR
General Commissioner for Sustainable Development
Ministry of Ecological Transition, France
Introduction
The worrying figures are multiplying, and many indicators are in the red.
Figure I.1. Some numerical data illustrating global warming
The multiplication of extreme climatic phenomena and anomalies (drought, intense heat waves, heavy rains, floods, etc.) is now recognized by all.
The growing consumption of and demand for energy has generated greenhouse gas waste with very noticeable consequences. According to Jancovici and Grandjean (2006), 80% of the energy consumed in the world contributes to global warming.
Faced with the climate emergency, new political decisions are gradually emerging.
The French law of August 17, 2015, on the energy transition for green growth was put in place to:
establish a robust and sustainable energy model in the face of energy supply challenges, price trends, resource depletion and environmental protection imperatives (Legifrance, law no. 2015-992).
Specific targets have been proposed to reduce greenhouse gas emissions, reduce energy consumption and promote renewable energy.
Figure I.2. The climate agreement, Paris, December 2015. The photograph shows Laurent Fabius, former Prime Minister of France and currently serving as President of the Constitutional Council since 2016
More recently, the European Union has embarked on an ambitious climate policy. In November 2018, the European Commission presented a long-term strategy to achieve a climate-neutral economy by 2050, in order to implement the commitments made in the Paris Agreement (Actualité Parlement européen 2018).
This agreement was adopted at the Paris Climate Conference (COP21) in December 2015 (Commission européenne 2016). This was a historic event, as it represents the first global agreement on climate change. It was signed by 195 countries, including the European Union. As Laurent Fabius said, this is not a political agreement, but an agreement for the climate. It requires everyone to take responsibility.
The green pact or green deal for Europe proposes a roadmap that should lead to carbon neutrality in 2050 (Commission européenne 2019).
This goal is essential if we are to avoid disastrous climate change.
Energy transition, greenhouse gas reduction, carbon offsetting, carbon neutrality and the green deal are vital objectives. However, they are not the only ones. Everything cannot be reduced to a carbon rate. The energy transition must be carried out in an ecological manner, by giving ourselves the scientific and economic means capable of respecting life, whether human, animal or plant. It must be said that here too, many indicators are worrying:
– erosion of biodiversity, destruction of natural habitats of wild species, overexploitation of natural resources, multiplication of invasive animal and plant species that threaten already fragile ecosystems;
– sixth wave of extinction of species: a demonstrative example is the massive disappearance of insects, while the reproduction of 80% of flowering plants depends on them;
– environmental pollution: damage to aquatic systems threatening the quality of water resources, degradation of soil quality leading to a reduction in arable land at a time when demographic pressure is galloping and a reduction in air quality accompanied by the emission of particles, volatile organic compounds and gases harmful to humans, animals and plant species.
These few facts clearly prove that the energy transition must be ecological and environmental. All these problems are closely linked and intertwined.
How can we combine energy and ecological transition?
This book proposes to demonstrate that the implementation of renewable energies can be accompanied by an agricultural transition; that it can also accelerate ambitious and innovative ecological programs in harmonious interaction with many fields of activity (biodynamic agriculture, health ecology, alternative medicine, preservation of insect biodiversity and enrichment of the quality of poor and not very fertile soils, etc.). This transition is in line with the Sustainable Development Goals (SDGs), notably those responding to the global challenges of clean and affordable energy (SDG 7), the fight against climate change (SDG 13) and the preservation of life on Earth (SDG 15).
Figure I.3. A necessary energy and ecological transition
Among the different renewable energies (solar, wind, hydraulic, biomass (plants, organic waste), geothermal, marine), solar energy is the most advanced.
The sun, a natural and renewable source of energy, can lead to two uses:
– electricity production (photovoltaic solar energy);
– heat production (solar thermal energy) (Ministère de la Transition écologique 2020a).
In this book, we will focus on photovoltaic solar energy, which transforms solar radiation into electricity through photovoltaic cells integrated into photovoltaic panels. We will show how the development of photovoltaic parks can be integrated with new agricultural activities (agrivoltaics) and ecological activities (ecovoltaics).
This book is divided into three main chapters:
– Chapter 1 introduces the basic concepts of photovoltaics and the photovoltaic industry through its various uses on rooftops, brownfield lands and drylands. It also addresses the degree of