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Freight transport: the way out of fossil fuels

Aurélien Bigo
Aurélien Bigo
Research Associate of the Energy and Prosperity Chair at Institut Louis Bachelier
Key takeaways
  • Freight transport is now largely dependent on oil: what are the technological options to get out of this dependence?
  • There are five main categories of technological options: switching to electricity, hydrogen, methane, liquid biofuels, or synthetic fuels.
  • Each mode of transport has its own technology option, e.g. for heavy goods vehicles, the use of electricity would be effective only for short distances. For longer distances, gas has yet to make its mark.
  • Whatever the mode, decarbonisation is likely to be slow, costly, or face major technical and implementation challenges.
  • It also depends on resources in tension. It is therefore necessary to prioritise the reduction of energy consumption in freight transport as much as possible.

Freight trans­port is now large­ly depen­dent on fos­sil fuels, both for glob­al logis­tics chains and in France. Heavy goods vehi­cles and light com­mer­cial vehi­cles are main­ly diesel-pow­ered. The same is true for riv­er trans­port boats, while mar­itime trans­port runs on heavy fuel oil. Air freight depends on paraf­fin. Only rail freight has already made a sig­nif­i­cant shift away from liq­uid fuels and oil.

To meet the cli­mate chal­lenge, decar­bon­i­sa­tion of the sec­tor is essen­tial, but has not yet begun. While the first arti­cle in this series point­ed out the five levers for decar­bon­is­ing freight trans­port (mod­er­a­tion of trans­port demand, modal shift, vehi­cle fill­ing, vehi­cle ener­gy con­sump­tion, ener­gy decar­bon­i­sa­tion), this one focus­es on the last lever of ener­gy decar­bon­i­sa­tion. And asks: what are the tech­no­log­i­cal options for mov­ing freight trans­port away from its depen­dence on oil?

Decarbonisation options available

It is pos­si­ble to give 5 main cat­e­gories to find your way through the tech­no­log­i­cal options for doing with­out oil in trans­port. The first option is to switch to elec­tric, about 90% of which is already low car­bon in France1. Elec­tric motors are also more ener­gy effi­cient than com­bus­tion engines, which makes them a pre­ferred option when pos­si­ble. Because the vol­ume of bat­ter­ies to be car­ried makes electrics unthink­able for cer­tain heavy modes, such as air or sea trans­port (apart from a few niche appli­ca­tions over short distances).

Anoth­er option that relates to elec­tric is hydro­gen. The main means of low-car­bon hydro­gen pro­duc­tion envis­aged is indeed the elec­trol­y­sis of water, which requires elec­tric­i­ty. And in addi­tion to the inter­nal com­bus­tion engine option for using hydro­gen in the vehi­cle, the fuel cell option allows the hydro­gen to be con­vert­ed back into elec­tric­i­ty for use in an elec­tric motor. The main advan­tage of hydro­gen is that it elim­i­nates the con­straints of range and bat­tery recharg­ing, par­tic­u­lar­ly for heav­ier vehi­cles. How­ev­er, hydro­gen pro­duc­tion is still 95% depen­dent on fos­sil fuels, and is a less ener­gy-effi­cient option than direct elec­tri­fi­ca­tion, which still presents many tech­ni­cal and eco­nom­ic chal­lenges for its deploy­ment in transport.

Anoth­er gas that is often men­tioned is methane, also called nat­ur­al gas for its fos­sil-derived ver­sion, or bio­gas or renew­able gas for the low-car­bon-derived ver­sions. Only this bio­gas is inter­est­ing from cli­mate point of view. But, although it is grow­ing rapid­ly, gas pro­duc­tion from bio­mass methani­sa­tion (agri­cul­tur­al efflu­ents, inter­me­di­ate crops, bio-waste, co-prod­ucts, or crop residues, etc.) will only account for around 2% of gas con­sump­tion in France in 20222. And bio­gas will only be able to account for a very sig­nif­i­cant share of gas con­sump­tion if there is a sharp drop in the vol­umes con­sumed, which today are main­ly in the build­ing and indus­tri­al sectors.

Liq­uid bio­fu­els are also pro­duced from bio­mass. They are more devel­oped and are already incor­po­rat­ed into road fuels, up to a lit­tle over 8% in 2022 for diesel3. How­ev­er, the pro­duc­tion of this biodiesel is far from being vir­tu­ous to date: more than three quar­ters of the raw mate­ri­als used are import­ed, most of them come from crops that com­pete with food uses4, and the reduc­tions in CO2 emis­sions are very lim­it­ed com­pared to oil, when all the impacts are considered.

Final­ly, syn­thet­ic fuels (or elec­tro­fu­els or e‑fuels) are at the inter­face of sev­er­al ener­gy car­ri­ers already men­tioned. They con­sist of using low-car­bon elec­tric­i­ty to pro­duce hydro­gen, which is com­bined with CO2 (or nitro­gen for e‑ammonia) to make liq­uid or gaseous fuels5. Their main advan­tage is that they can replace many of the fuels cur­rent­ly in use, with­out any mod­i­fi­ca­tion to vehi­cles. On the oth­er hand, they suf­fer from many chal­lenges: their pro­duc­tion is only in its infan­cy, and must be based on very low-car­bon elec­tric­i­ty in order to present a large­ly favourable car­bon bal­ance; the elec­tric­i­ty require­ments for their pro­duc­tion are very high, in the order of 4–5 times high­er for e‑diesels than for direct use in an elec­tric vehi­cle6; as a result, their cost is also very high, even more so in the short term7.

It is clear from these dif­fer­ent options that their cur­rent car­bon foot­print is quite var­ied, depend­ing on the lev­el of decar­bon­i­sa­tion of these dif­fer­ent ener­gies or ener­gy car­ri­ers. For the moment in France, only elec­tric­i­ty is large­ly decar­bonised. There­fore, the lev­els of deploy­ment, but also the con­straints and chal­lenges to be met for their devel­op­ment are var­ied. This invites us to try to find the most rel­e­vant ener­gy mix accord­ing to the many issues to be inte­grat­ed (tech­ni­cal, eco­nom­ic, cli­mat­ic, resources, etc.).

The example of heavy goods vehicles: how to get out of oil?

Road trans­port accounts for three quar­ters of green­house gas emis­sions from goods trans­port in France (includ­ing inter­na­tion­al trans­port), with 60% from heavy goods vehi­cles and 16% from light com­mer­cial vehi­cles. For the lat­ter vehi­cles and for HGVs oper­at­ing in the last few kilo­me­tres or the short­est dis­tances, elec­tric pow­er should rapid­ly become the dom­i­nant engine. For longer dis­tances, com­pe­ti­tion is stronger and illus­trates a sig­nif­i­cant con­flict between the most envi­ron­men­tal­ly friend­ly options and the avail­abil­i­ty of these solu­tions, par­tic­u­lar­ly in the short term.

Aver­age car­bon foot­print over the life­time of a road trac­tor sold in France in 2020 (in gCO2e/km). CNG: com­pressed nat­ur­al gas; FC: fuel cell. Source: Car­bone 4, 2022.

The fig­ure above shows that, as of 2020, three options allow for very sig­nif­i­cant reduc­tions in green­house gas emis­sions for road trac­tors8. These same options will even achieve reduc­tions in the order of a six­fold reduc­tion for a truck sold in 2030 com­pared to diesel9.

Sales of gas-fuelled trucks account­ed for 4.5% of the mar­ket in 2022 for trucks over 7.5 tonnes and rep­re­sent the lead­ing alter­na­tive ener­gy to diesel10, but bio­gas is only avail­able in lim­it­ed quan­ti­ties11. The pro­duc­tion of low-car­bon hydro­gen is only in its infan­cy and the sup­ply of trucks is not expect­ed to take off strong­ly before 2030. Final­ly, the sup­ply of elec­tric trucks is low to date, and they account­ed for only 0.3% of truck sales in 2022 in France12.

How­ev­er, in ear­ly 2023, the Euro­pean Com­mis­sion pro­posed a revi­sion of the CO2 emis­sion stan­dards for new heavy goods vehi­cles, aim­ing for a 45% reduc­tion in these emis­sions in 2030 com­pared to 201913. The main man­u­fac­tur­ers already seem to be in line with this objec­tive and are aim­ing for around 50% of sales of heavy goods vehi­cles with zero emis­sions by the end of the decade14. This tar­get will be met main­ly by elec­tric vehi­cles, sup­ple­ment­ed by a small­er pro­por­tion of hydro­gen trucks.

It should be not­ed that elec­tric vehi­cles could also be deployed over long dis­tances with the help of elec­tric high­ways, which allow vehi­cles to recharge dur­ing their use by mod­i­fy­ing the infra­struc­ture (elec­tri­fi­ca­tion by cate­nary, rail, or induc­tion)15. While these tech­nolo­gies make it pos­si­ble to reduce the con­straints linked to the bat­ter­ies, their range, and their recharg­ing (high pow­er demands for rapid recharg­ing, pause times, etc.), the choice of the tech­nol­o­gy to be favoured is still not very mature and deploy­ment would require coor­di­na­tion at Euro­pean lev­el to be of real interest.

Main advan­tages (green) and dis­ad­van­tages or dis­in­cen­tives (orange) of dif­fer­ent decar­bon­i­sa­tion options for long-dis­tance heavy goods vehi­cles, in qual­i­ta­tive terms16.

This exam­ple also shows the dif­fi­cul­ty in choos­ing the engines and tech­nolo­gies to be pre­ferred. The diver­si­ty of decar­bon­a­tion options is obvi­ous­ly an asset and can help gain resilience accord­ing to future con­straints. How­ev­er, no solu­tion is per­fect, and it will not nec­es­sar­i­ly be effi­cient or even pos­si­ble to invest in the sup­ply or recharg­ing infra­struc­ture for all decar­bon­i­sa­tion options, or for man­u­fac­tur­ers to invest in all engines at once. It is pos­si­ble that one or two options will end up being the most pop­u­lar for each mode, whether for heavy goods vehi­cles or for oth­er modes.

Which energies for the other modes?

For the oth­er modes of trans­port, a mix of dif­fer­ent tech­nolo­gies is often men­tioned. For inland water­ways, con­ver­sion to bio­fu­els or bio­gas is the eas­i­est to envis­age from a tech­ni­cal point of view. But hydro­gen or even elec­tric pow­er could also play a role in decar­bon­is­ing this mode, because of the dis­tances or even vol­umes that are still rea­son­able to imag­ine car­ry­ing bat­ter­ies (which are heavy) or hydro­gen (which takes up a lot of space).

For mar­itime trans­port, gas-pow­ered ships and then con­vert­ing them to bio­gas have long been the pre­ferred way of mov­ing away from oil. Sail­ing ships are also like­ly to devel­op, at least as a propul­sion aid. There is also increas­ing talk of syn­thet­ic fuels, in par­tic­u­lar e‑ammonia or e‑methanol for this mode, which is like­ly to be par­tic­u­lar­ly long and dif­fi­cult to decar­bonise. The same applies to air trans­port, where the tran­si­tion from oil should be based pri­mar­i­ly on sec­ond-gen­er­a­tion bio­fu­els, syn­thet­ic paraf­fin or hydro­gen for appli­ca­tions that allow it.

Pre­ferred (dark green) and planned (light green) engines and ener­gies per freight trans­port mode for its decarbonisation.

Final­ly, the rail­ways are already large­ly elec­tri­fied, but about 15% of their ener­gy con­sump­tion is still based on diesel17. The elec­tri­fi­ca­tion of lines is the most effi­cient solu­tion and could be fur­ther extend­ed. For the lines that will remain non-elec­tri­fied, bat­tery elec­tric, bio­fu­els and hydro­gen are the main alter­na­tives18.

What are the impli­ca­tions for the ener­gy transition?

To move away from oil, freight trans­port will have to rely on a vari­ety of ener­gies in the future, while pas­sen­ger trans­port will be large­ly dom­i­nat­ed by elec­tric pow­er (as illus­trat­ed by the four ADEME Transition(s) 2050 sce­nar­ios below19).

What­ev­er the mode, decar­bon­i­sa­tion is like­ly to be slow, cost­ly, or face major tech­ni­cal and imple­men­ta­tion chal­lenges. The main decar­bon­i­sa­tion options also depend on resources (met­als, bio­mass, elec­tric­i­ty, etc.) that are under pres­sure, whether with­in trans­port, with oth­er sec­tors of the econ­o­my or because of the impacts linked to their exploita­tion con­di­tions (impacts on bio­di­ver­si­ty, geopol­i­tics, social, etc.).

Trans­port ener­gy demand in 2050 by vec­tor and by sce­nario, for pas­sen­ger trans­port, freight trans­port and bunkers (inter­na­tion­al trans­port). Source: ADEME, 2021.

This should lead to pri­ori­tis­ing the reduc­tion of ener­gy con­sump­tion in freight trans­port as much as pos­si­ble, using the levers of sobri­ety (men­tioned in the first arti­cle and detailed in the next two arti­cles in the series). Both to decar­bonise the sec­tor quick­ly enough to meet the objec­tives, but also to lim­it the finan­cial cost and oth­er envi­ron­men­tal impacts of the transition.

1The RTE bal­ance sheet for 2022 gives a share of 87% of elec­tric­i­ty from decar­bonised sources in French pro­duc­tion, com­pared with around 91% over the peri­od 2014–2021. (RTE, 2023)
2In 2022, bio­methane pro­duc­tion account­ed for 7.0 TWh (up 61% from 2021), or 1.6% of nat­ur­al gas con­sump­tion (GRTgaz, 2023). See also the ori­gin of the raw mate­ri­als on (FranceA­griMer, 2022).
3Ufip Ener­gies et Mobil­ités, 2023
5IFPEN, 2023.
6Sac­chi et al, 2022. The same pub­li­ca­tion gives the fig­ures in terms of car­bon foot­print.
7In the EU, e‑fuels would have a pro­duc­tion cost more than 3 times high­er than petro­le­um fuels in 2035, and rather 6 to 10 times high­er in the short term, and even high­er in small-scale exper­i­men­tal projects. See in par­tic­u­lar the stud­ies : ICCT, 2022 ; Ceru­lo­gy, 2017 ; Con­cawe, Aram­co, 2022.
8Car­bone 4, 2022.
9Car­bone 4, 2020.
10IDDRI, 2023.
1136% of the nat­ur­al gas con­sumed in France in 2022 was of renew­able ori­gin, via guar­an­tees of ori­gin (GRTgaz, 2023). But over­all, bio­gas only rep­re­sents less than 2% of total gas con­sump­tion in France, so the ques­tion of how to allo­cate this poten­tial between sec­tors is a major one.
12136 elec­tric trucks were sold in France (AVERE, 2023) and 3 hydro­gen fuel cell trucks (Le Monde, 2023), on more than 44,000 trucks over 5 tonnes sold (CCFA, 2023).
13The tar­gets are also ‑65% by 2035 and ‑90% from 2040 onwards, small­er reduc­tions than for cars but still sig­nif­i­cant in view of the time­frame. (Euro­pean Com­mis­sion, 2023)
14T&E, 2023. See also : PwC, 2022.
15MTE, 2021.
16The table is based on the oth­er stud­ies cit­ed in this arti­cle. See also Cunanan et al, 2021 ; Bhard­waj, Mostofi, 2022.
17CGDD-SDES, 2022.
18ADEME, 2020.
19ADEME, 2021

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