Agriculture consumes little energy, but emits a lot of greenhouse gases

First of all, it should be poin­ted out that the agri­cul­tur­al (and forestry) sec­tor is a spe­cial case. Only 13% of the green­house gases (GHGs) released – in this case CO₂ – are linked to its energy con­sump­tion in France¹ (editor’s note: most of the emis­sions are linked to the release of CH₄ and N₂O, see also art­icle 1). These emis­sions linked to energy con­sump­tion rep­res­ent 2% of France’s total emissions.

The sec­tor con­sumes 4.5 mil­lion tonnes of oil equi­val­ent per year in France, mostly for agri­cul­tur­al machinery (75%). Live­stock build­ings and heated green­houses are the oth­er two energy con­sump­tion items. Agriculture’s final energy con­sump­tion rep­res­ents 3% of France’s total energy con­sump­tion, a fig­ure that has remained stable since 2004².

Anoth­er par­tic­u­lar­ity of the agri­cul­tur­al sec­tor is the com­pos­i­tion of its energy mix, which is dom­in­ated by oil products. The most import­ant step for redu­cing the energy foot­print is to reduce depend­ence on fossil fuels. The oth­er step is to reduce energy con­sump­tion, and the evol­u­tion of agri­cul­tur­al prac­tices makes it pos­sible to inter­vene on both levels.

It is a ques­tion of rethink­ing the use of machines to lim­it inter­ven­tions: land con­sol­id­a­tion, modi­fic­a­tion of cul­tiv­a­tion schemes or even redu­cing the num­ber of weed­ing trips. The elec­tri­fic­a­tion of machines or the use of bio­meth­ane are also inter­est­ing, but these tech­no­lo­gies are not yet mature. Oth­er tech­nic­al modi­fic­a­tions also make it pos­sible to reduce the energy foot­print of farms. For example, insu­lat­ing green­houses, rethink­ing their lay­out to max­im­ise sol­ar gain and lim­it heat loss, equip­ping live­stock build­ings with energy recov­ery sys­tems, and micro-sprink­ler or drip irrig­a­tion systems.

We have quan­ti­fied the pos­sible reduc­tions in a pro­spect­ive exer­cise designed with the play­ers in the sec­tor. Energy sav­ings amount to 26% by 2050 for a trend scen­ario where the best cur­rent tech­no­lo­gies are massively deployed. They can reach as much as 43% in a the most pro­act­ive scenario.

The agri­cul­tur­al sec­tor accounts for 20% of France’s renew­able energy pro­duc­tion, equi­val­ent to its total energy con­sump­tion³. This pro­duc­tion comes from nearly 50,000 farms, i.e. about 13% of the farms in operation.

Most of the pro­duc­tion is based on bio­fuels, to which 800,000 to one mil­lion hec­tares in France are devoted. I think that the future lies more with second-gen­er­a­tion bio­fuels, which make use of by-products such as wood waste. How­ever, this is still a rel­at­ively new field

Farms account for 83% of wind energy pro­duc­tion, as well as 13% of photo­vol­ta­ic sol­ar energy, mainly installed on live­stock build­ings. This pro­duc­tion is increas­ing in line with nation­al devel­op­ment. Bio­meth­ane pro­duc­tion has been devel­op­ing rap­idly in recent years. The num­ber of install­a­tions is grow­ing rap­idly – more than 1,100 at the begin­ning of 2022 – and is increas­ingly mak­ing use of crop residues and inter­me­di­ate crops. Moreover, the major­ity of install­a­tions are mov­ing towards the intro­duc­tion of bio­meth­ane into the gas net­work. We estim­ate that the pro­duc­tion of renew­able energy by the agri­cul­tur­al sec­tor should triple between 2015 and 2050.

This is the ques­tion cur­rently being asked in the face of the boom in anaer­obic diges­tion (meth­an­isa­tion) and requires fur­ther con­sid­er­a­tion of the frame­work for its devel­op­ment. For example, if it is developed to main­tain a sys­tem of intens­i­fic­a­tion of live­stock farm­ing, we are not head­ing in the right dir­ec­tion. In Ger­many, crops ded­ic­ated to anaer­obic diges­tion have emerged, which divert food pro­duc­tion to energy production.

Bey­ond a simple energy pro­duc­tion pro­cess, anaer­obic diges­tion responds to many oth­er issues and can be used in sup­port of a vir­tu­ous agri­cul­tur­al pro­ject: bet­ter use of efflu­ents, plant­ing of plant cov­er and reduc­tion in the con­sump­tion of syn­thet­ic inputs through the adap­ted use of digestates.

Many energy oper­at­ors are inter­ested in agri­cul­tur­al land. The roofs of build­ings have long been equipped with photo­vol­ta­ic pan­els, and wind tur­bines have been installed in the fields: these install­a­tions gen­er­ate addi­tion­al income with very little impact on agri­cul­tur­al land.

We are cur­rently eval­u­at­ing agri-vol­ta­ic sys­tems – which we define as pro­jects where the photo­vol­ta­ic pro­duc­tion sys­tem provides an agri­cul­tur­al ser­vice – such as pro­tec­tion against frost or hot weath­er (shad­ing, photo­vol­ta­ic green­houses, etc.). The sec­tor is extremely new and little data is avail­able: for the moment we are pro­mot­ing exper­i­ments on small areas to quanti­fy the impact of such sys­tems on farms.