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.