58: Sustainable electro-mobility

Faced with the cli­mate change prob­lem and the ener­gy cri­sis that is loom­ing fol­low­ing the war in Ukraine, France has decid­ed to accel­er­ate its pace advanc­ing into the field of renew­able ener­gies. In this area, UTC and par­tic­u­lar­ly the UTC-Avenues lab­o­ra­to­ry team are involved on two fronts. That of elec­tro-mobil­i­ty with research work on the opti­mi­sa­tion of recharg­ing sta­tions cov­ered with pho­to­volta­ic (PV) pan­els but also that of ener­gy pro­duc­tion from PV installed on the uni­ver­si­ty premis­es. A move­ment that the ser­vice sec­tor decree — pub­lished in the French Offi­cial Jour­nal in 2019, requir­ing own­ers and occu­pants of both pri­vate and pub­lic ser­vice inten­sive build­ings to sig­nif­i­cant­ly reduce their ener­gy con­sump­tion com­pared to 2010, the ref­er­ence year — has accelerated.

Manuela Sechi­lar­iu is a full uni­ver­si­ty pro­fes­sor and Direc­tor of UTC’s Avenues research lab­o­ra­to­ry since 2016. Her research inter­ests include micro­grids and, more recent­ly, elec­tro-mobil­i­ty in gen­er­al. More specif­i­cal­ly, recharg­ing sta­tions cov­ered with pho­to­volta­ic pan­els and equipped with intel­li­gent con­trol systems.

These are research areas which, in view of the ongo­ing cli­mate change cri­sis, have stim­u­lat­ed a large num­ber of projects, both nation­al­ly and inter­na­tion­al­ly. The proof? ¨Projects at the nation­al lev­el that are part of the search for greater elec­tric mobil­i­ty. Thus, “Mobel”_City was launched in 2017 and PV2E_Mobility in 2020, both financed by the French Agency for Eco­log­i­cal Tran­si­tion (ADEME), while in July 2021, it was the turn of Smart_ PV4EV spe­cif­ic to UTC with­in the frame­work of a State-Region­al Plan­ning con­tract (CPER) «Elec­tric Ener­gy 4.0» (EE4.0). «The first call, where we were the win­ner, in 2017, fol­low­ing a call for projects is also sup­port­ed by an indus­tri­al part­ner, SYSTRA, spe­cialised in trans­port-relat­ed issues on a nation­al scale, but also by the Aggloméra­tion de la Région de Com­piègne (Greater Com­pieg­ne ARC). One of to deploy recharg­ing sta­tions for elec­tric vehi­cles (EVs) pow­ered by pho­to­volta­ic (PV) pan­els. This project illus­trates both the skills accu­mu­lat­ed at Avenues and the inter­dis­ci­pli­nar­i­ty that reigns there, since it is at the cross­roads of the fields of trans­port — elec­tric mobil­i­ty, renew­able ener­gies, urban plan­ning and sus­tain­able ter­ri­to­ry, but also social sci­ences,” explains Manuela Sechilariu.

The sec­ond project, in the same vein, has attract­ed a num­ber of part­ners, includ­ing the CEA, Enedis, Tec­sol, a com­pa­ny spe­cialised in solar ener­gy, and SAP, who spe­cial­ize in soft­ware and intel­li­gent or “smart” man­age­ment of recharg­ing sta­tions. The project focus­es on on-board and sta­tion­ary PV ener­gy and pow­er for (and in) trans­porta­tion, with Avenues being in charge of stud­ies on sys­tems and infra­struc­tures equipped with sta­tion­ary PV sources to used for EV recharging.

Pur­su­ing on the same Smart_PV4EV issue. «This time, the aim is to show the advan­tage of PV in EV charg­ing and to look at the soci­etal impact and social accept­abil­i­ty,» she adds.

Final­ly, on an inter­na­tion­al lev­el, the PVPS sci­en­tif­ic pro­gramme of the Inter­na­tion­al Ener­gy Agency (IEA). «This project, which ter­mi­nates end 2024, rep­re­sents the French con­tri­bu­tion to Task 17¹ of the IEA pro­gramme ded­i­cat­ed to PV and trans­porta­tion,» she says.

What exact­ly is the role of Avenues research sci­en­tists in these projects? «We are the project lead­ers and coor­di­na­tors of Mobel_City and PV2E_Mobility. As for the inter­na­tion­al project involv­ing the IAE, I am Task Man­ag­er with a Japan­ese col­league and leader of sub­task 2. The lat­ter sub­task address­es the fea­si­bil­i­ty con­di­tions and require­ments for the best use of EV recharg­ing sta­tions with PV pan­els. Final­ly, Smart_PV4EV, for which I am respon­si­ble, is part of a large CPER project involv­ing most of the elec­tri­cal engi­neer­ing lab­o­ra­to­ries in the Hauts de France region,’ says Manuela Sechilariu.

All these projects aim at opti­miz­ing the use of PV for both mobil­i­ty and build­ings. This is a goal that calls for numer­ous the­o­ret­i­cal stud­ies upstream. «It is a ques­tion of design­ing and test­ing a set of method­olo­gies and tools, both for imple­men­ta­tion and siz­ing and for reg­u­la­tion and smart sys­tem con­trol. Indeed, the recharg­ing sta­tion is based on a micro­grid made up of sta­tion­ary stor­age, PV pan­els, a con­nec­tion to the nation­al grid and has loads such as build­ings or EVs. In order to max­imise user sat­is­fac­tion and the use of PV ener­gy, algo­rithms are being devel­oped that allow both off-line opti­mi­sa­tion, i.e., out­side real-time oper­a­tion, and on-line opti­mi­sa­tion for real-time oper­a­tion con­trol. We are show­ing that an EV can be recharged, even in Decem­ber in Com­piègne, with more than 75% PV ener­gy, enabling the vehi­cle to trav­el 40 km,» she explains.

How­ev­er, in this type of project, the the­o­ret­i­cal stud­ies are not lim­it­ed to the sci­en­tif­ic and tech­ni­cal aspects but also involve oth­er fields of knowl­edge, since the aim is to devel­op more wide­ly the uses of PV. «For exam­ple, we are call­ing on urban plan­ners to devel­op method­olo­gies and deci­sion­mak­ing tools for ter­ri­to­r­i­al actors con­cern­ing the most judi­cious deploy­ment of recharg­ing sta­tions. We are also work­ing with UTC-Costech, a social sci­ence lab­o­ra­to­ry at UTC, to study the soci­etal impact and accept­abil­i­ty of the project”.

 *Pho­to­volta­ic Pow­er Pro­gramme Sys­tems Task 17 (https://iea-pvps.org/research-tasks/ pv-for-transport/) 

Fab­rice Loc­ment is a uni­ver­si­ty pro­fes­sor and research sci­en­tist in the UTC-Avenues research unit. He is also Direc­tor of the university’s Urban Engi­neer­ing Depart­ment (GU). His research on elec­tro-mobil­i­ty has led to the set­ting up of STELLA, which will be trans­formed into a Liv­ing Lab in the autumn of 2022.

With­in AVENUES, the idea of the STELLA or ‘Smart’ Trans­port and Ener­gy Liv­ing LAb tech­nol­o­gy plat­form is a long­stand­ing project. MBut it was in 2016, thanks to fund­ing via a State/Region Plan­ing con­tract (CPER), that it was launched and became oper­a­tional at the begin­ning of 2017 and final­ly trans­formed into a Liv­ing Lab.

Con­crete­ly? «It is an exper­i­men­tal set-up that allows the val­i­da­tion of con­cepts relat­ed to tech­nol­o­gy, but not only with tech­no­log­i­cal objects, since it also intro­duces human beings in inter­ac­tion with these objects. Hence the name «Liv­ing Lab». So in STELLA, there are pho­to­volta­ic pan­els (PV), elec­tric vehi­cles (EV), back-up pow­er stor­age and a con­nec­tion to the nation­al grid, but it is the human beings who are at the heart of the Lab,» he explains. What made it hap­pen? «When we saw the large, uncov­ered car park at the university’s Inno­va­tion Cen­tre, the idea took hold in 2010. We thought it would be inter­est­ing to install PV arrays on these unused sur­faces. Of course, at first it was the research ideas that guid­ed us. At that time, we were work­ing with Sun­vie, a com­pa­ny spe­cialised in PV tech­nol­o­gy, but we didn’t have the fund­ing to go fur­ther. And it was in 2016, thanks to the CPER, that the project came to fruition,» he explains.

This was a nat­ur­al devel­op­ment for Avenues, which his­tor­i­cal­ly housed the PLER plat­form, an acronym for Local Renew­able Ener­gy Pro­duc­tion. «With PLER, we are still in a mul­ti-source, mul­ti­load sys­tem, but the aim is to pow­er a build­ing. PLER still exists and works very well. Spe­cial fea­tures? It’s a real research plat­form with cables every­where, but it’s a bit lim­it­ed as soon as you increase the pow­er lev­el. But with the prob­lem of elec­tro-mobil­i­ty, the pow­er sup­ply for EVs is need­ed. And with STELLA, we change the for­mat. It was no longer the same pow­er rat­ings or the same oper­a­tion. Above all, STELLA allows for both build­ing and EV appli­ca­tions,» Fab­rice Loc­ment points out.

The trans­for­ma­tion of STELLA into a Liv­ing Lab? “Until now, with STELLA, we emu­lat­ed EVs, i.e., we car­ried out tests on the UTC’s own fleet of EVs, look­ing in par­tic­u­lar at their their ener­gy con­sump­tion pat­tern, in order to emu­late them on sys­tems phys­i­cal­ly present at STELLA and thus be able to repeat the tests. At this stage, the human aspect was not tak­en into account. With the Liv­ing Lab, we will go fur­ther and put the human fac­tor at the heart of the work. For exam­ple, the PV shade house, which cov­ers 9 park­ing spaces, 3 of which are reserved for EVs ded­i­cat­ed to research at the Avenues lab­o­ra­to­ry, will be going ful­ly elec­tric. We have already installed three two-head­ed recharg­ing sta­tions for UTC staff,» he says. A devel­op­ment that will make it pos­si­ble to analyse the behav­iour of real users with real con­straints. «Our goal is to have the Liv­ing Lab up and run­ning by Sep­tem­ber. At that time, we will con­tact the staff to find out who has an EV, who would be inter­est­ed in recharg­ing. They will then be able to use the sys­tem in return for their per­mis­sion to retrieve all the data. That is, the charge when they arrive, the charge when they leave, the dura­tion of the charge, the type of recharge — slow or fast, etc. Data that will allow us to set up con­trol laws to intel­li­gent­ly recharge the vehi­cles,» he adds. This project is in line with their research and its main objec­tive is to min­imise the imbal­ance in the nation­al elec­tric­i­ty net­work. «The ener­gy reser­voir of a bat­tery in an EV such as Renault’s Zoé or Peugeot’s e208 is around 50 kWh. How­ev­er, the cur­rent shad­ing sys­tem only pro­duces 29 kW even under almost opti­mal con­di­tions. Hence the project to build 10 addi­tion­al shad­ing sys­tems in the Inno­va­tion Cen­tre car park,» con­cludes Fab­rice Locment. 

Pro­fes­sor Fabi­en Lamar­que is a senior lec­tur­er, respon­si­ble for the «Urban Engi­neer­ing» major and an asso­ciate mem­ber of the UTC AVENUES research unit. He leads the work­shop-project «Pho­to­volta­ic ener­gy pro­duc­tion at UTC». Julien Saut­jeau, a 5th year UTC stu­dent in the «Build­ing» spe­cial­i­ty, is also part of it.

This is a project-work­shop part of the sus­tain­able devel­op­ment pol­i­cy ini­ti­at­ed by the uni­ver­si­ty. UA pol­i­cy that the ser­vice sec­tor gov­ern­ment decree — pub­lished in the French Offi­cial Jour­nal in 2019, requir­ing own­ers and occu­pants of both pri­vate and pub­lic service*intensive build­ings to sig­nif­i­cant­ly reduce their ener­gy con­sump­tion com­pared to 2010, the ref­er­ence year — has accel­er­at­ed. This reduc­tion can be achieved through two main solu­tions: improv­ing the ener­gy insu­la­tion enve­lope of build­ings and/or the pro­duc­tion of renew­able ener­gy (RE).

«In the con­text of the GU urban engi­neer­ing course, we have a very pro­fes­sion­al teach­ing for­mat which involves both lec­tur­ers and stu­dents in pro­ject­work­shops respon­si­ble for respond­ing to orders placed by var­i­ous, dif­fer­ing clients. For the pro­ject­work­shop on pho­to­volta­ic (PV) ener­gy pro­duc­tion, the order came from the UTC’s Prop­er­ty Man­age­ment Depart­ment (DPI),» explains Fabi­en Lamar­que. It is a mis­sion that requires three main skills. The first con­cerns the entire ener­gy con­ver­sion process, the sec­ond involves mod­el­ling and cal­cu­la­tion to mea­sure the sun­shine poten­tial at the var­i­ous build­ings and the third con­cerns the inter­face between RE pro­duc­tion and the build­ings. The lat­ter involves gen­er­al knowl­edge of the build­ing, tech­ni­cal con­straints, reg­u­la­tions, etc. «Hence our deci­sion to set up a group of stu­dents and lec­tur­ercum- research sci­en­tist pos­sess­ing all three skills,» he adds.

What are the objec­tives of this project-work­shop? «The aim is to study ways of reduc­ing the ener­gy con­sump­tion of build­ings and to devel­op a dig­i­tal mod­el of exist­ing sites in order to define those most suit­able for the instal­la­tion of PV and thus ensure the best pos­si­ble ener­gy opti­mi­sa­tion,» empha­sis­es Julien Sautjeau.

A project that makes sense with build­ings that, for the most part, were built in the 1970s and whose ther­mal enve­lope is poor, to say the least. A project which, of course, has a cost. «Dur­ing our inves­ti­ga­tion, we eval­u­at­ed the return on invest­ment of thePV pan­els, which have a cer­tain lifes­pan but also an envi­ron­men­tal impact. The ener­gy gain is obvi­ous, but we went fur­ther and eval­u­at­ed the envi­ron­men­tal gain gen­er­at­ed by the PV pan­els com­pared to the French ener­gy mix,» explains Fabi­en Lamarque.

«The French ener­gy mix, which is large­ly made up of nuclear pow­er, emits lit­tle CO2. For PV, we car­ried out a life cycle analy­sis, i.e., from the extrac­tion of raw mate­ri­als to installation/operation and up to the end of life and sub­se­quent recy­cling. So far, PV has had dif­fi­cul­ty com­pet­ing with nuclear pow­er in terms of its car­bon foot­print,» adds Julien Sautjeau.

The con­clu­sions of the project? «In the course of the study, we worked out dif­fer­ent sce­nar­ios for installing PV pan­els. We act­ed as project man­age­ment assis­tants. We detailed both the poten­tial gains and the risks asso­ci­at­ed with each instal­la­tion, whether it be on the roofs of build­ings, on the ground, or on car park shades. It’s a kind of diag­no­sis that we car­ried out for the DPI,» con­cludes Fabi­en Lamarque.

Nathalie Molines has been a lec­tur­er in geog­ra­phy at UTC since 2006. She is attached to the UTC-AVENUES research unit and works on deci­sion sup­port issues for ter­ri­to­r­i­al transition.

In order to com­ply with its inter­na­tion­al com­mit­ments to reduce green­house gas emis­sions (GHG), France must dras­ti­cal­ly reduce its emis­sions from trans­porta­tion, and in par­tic­u­lar from indi­vid­ual trans­port vehi­cles. UOne of the ways of reduc­ing these emis­sions is through elec­tro­mo­bil­i­ty. How­ev­er, this implies, upstream, an opti­mised deploy­ment of recharg­ing stations.

Reduc­ing trans­port-relat­ed GHGs? «In the Com­piègne conur­ba­tion, for exam­ple, indi­vid­ual trans­porta­tion accounts for 16% of GHG emis­sions, which is the third largest source of emis­sions after hous­ing and agri­cul­ture. There are sev­er­al ways to reduce GHGs. It is a ques­tion of trans­form­ing people’s habits by encour­ag­ing them to use pub­lic trans­port or bicy­cles, for exam­ple. To do this, we need to work on urban forms by den­si­fy­ing areas served by pub­lic trans­port rather than opt­ing for urban sprawl, but also to devel­op soft mobil­i­ty by build­ing cycle paths and, final­ly, to switch a sig­nif­i­cant pro­por­tion of the exist­ing inter­nal com­bus­tion engine car fleet to elec­tric vehi­cles. The finan­cial incen­tives for the pur­chase of a bicy­cle or an elec­tric vehi­cle are there to facil­i­tate this tran­si­tion,» she assures. These mea­sures, if they suc­ceed, will prob­a­bly increase the num­ber of elec­tric vehi­cles on the road. Between 2018 and 2021, the num­ber of elec­tric car reg­is­tra­tions increased by more than 400% (source: Avere France)! The num­ber of recharg­ing points is strug­gling to keep up. «In 2018, there was one recharg­ing point for just under sev­en vehi­cles. That’s less than one per town­ship. As a result, it is main­ly peo­ple liv­ing in indi­vid­ual hous­es who acquire an elec­tric vehi­cle,» observes Nathalie Molines.

Hence the desire of France and oth­er Euro­pean coun­tries to increase the net­work of elec­tric recharg­ing points, but also to opti­mise their ter­ri­to­r­i­al location.

As a geo­g­ra­ph­er, Nathalie Molines has main­ly worked on the issues of plan­ning and opti­mis­ing recharg­ing sta­tions at the urban level.

The under­ly­ing idea? «The idea is to think about the loca­tion of the recharg­ing sta­tions before­hand in order to define the places where they will be the most use­ful and the most used. Indeed, dur­ing a study day with the var­i­ous trades involved in this theme, we realised that some of the recharg­ing points installed, for exam­ple in the Hauts de France region, were nev­er used, or used very lit­tle. It is also a ques­tion of think­ing about the right type of ter­mi­nals to be installed since, depend­ing on the mod­el, recharg­ing can be more or less rapid. Final­ly, it is a ques­tion of antic­i­pat­ing their impact on the elec­tric­i­ty net­work. This is the work of Manuela Sechi­lar­iu and Fab­rice Loc­ment,» she explains.

A method­ol­o­gy for analysing the ter­ri­to­r­i­al poten­tial has been devel­oped as part of the MOBEL_CITY project and test­ed in the city of Com­piègne. A tool for search­ing for poten­tial loca­tions for recharg­ing sta­tions, which can be used through­out France, has also been devel­oped. It is free and avail­able online.

What about the state of the art in urban plan­ning and opti­mi­sa­tion? «Sev­er­al meth­ods exist for plan­ning and opti­mis­ing these net­works. First­ly, it is a ques­tion of analysing the capac­i­ty of the exist­ing net­work to absorb addi­tion­al demand, know­ing the loca­tion of typ­i­cal users for the loca­tion of recharg­ing sta­tions and final­ly observ­ing the uses of a ter­ri­to­ry in order to define the type of charg­ing to be deployed,» con­cludes Nathalie Molines. 

As a PhD stu­dent at UTC since 2019, Saleh Cheikh Mohamad pre­sent­ed his the­sis in Octo­ber 2022, focussing on the opti­miza­tion of ener­gy flows in PV (pho­to­volta­ic) pow­ered charg­ing sta­tions ded­i­cat­ed to all-elec­tric vehi­cles (EVs).

It was dur­ing his intern­ship at UTC’s Avenues lab­o­ra­to­ry that he became inter­est­ed in these top­ics. «The idea was to devel­op a graph­i­cal inter­face allow­ing inter­ac­tion between the user and the micro­grid or recharg­ing sta­tion used for elec­tric vehi­cles»; he says.

As an active par­tic­i­pant in the PV2E_Mobility and IEA PVPS Task 17 projects, Saleh Cheikh Mohamad explored dif­fer­ent issues relat­ed to the opti­mi­sa­tion of ener­gy man­age­ment for recharg­ing sta­tions in the frame­work of his the­sis. «First, we had to under­stand the ener­gy sys­tem of a recharg­ing sta­tion pow­ered by pho­to­volta­ic (PV) pan­els, equipped with a stor­age sys­tem, a con­nec­tion to the nation­al grid and ded­i­cat­ed to pow­er­ing EVs. Sec­ond­ly, we had to opti­mise the flow of ener­gy between the dif­fer­ent pow­er sources — PV, stor­age, grid — in order to min­imise the ener­gy cost for the user. Con­se­quent­ly, depend­ing on whether you are in off-peak or peak hours, the ener­gy cost of the grid is dif­fer­ent. It is obvi­ous­ly low­er in the first case than in the sec­ond. The inter­face offers three recharg­ing thresh­olds — slow, medi­um or fast. A mul­ti-cri­te­ria inter­face is pro­vid­ed to help the user. Final­ly, the opti­mi­sa­tion is launched in real time each time an EVs arrives and anoth­er departs,» he explains.

An inter­face that allows the user to indi­cate his/ her charg­ing rate pref­er­ences and thanks to an intel­li­gent algo­rithm that includes hourly solar radi­a­tion fore­casts from Météo France, the opti­mi­sa­tion is car­ried out in real time. «Depend­ing on the choice made by the user, recharg­ing will be done direct­ly by PV, by stor­age or by the nation­al grid, or even a mix of the three based on the results of the opti­mi­sa­tion cal­cu­la­tions,» he notes.

Oth­er areas of research? «We have the V2G (Vehi­cle to Grid) issue. In this case, it is the elec­tric vehi­cles that can sup­ply the nation­al grid in the event of a con­sump­tion peak. This has the enor­mous advan­tage of send­ing ener­gy instant­ly to the grid rather than restart­ing a coal-fired pow­er sta­tion, for exam­ple. Of course, the pure­ly envi­ron­men­tal aspects of elec­tric vehi­cles, such as the lifes­pan or recy­cling of bat­ter­ies, require fur­ther in-depth stud­ies,» con­cludes Saleh Cheikh Mohamad. 

Amalie Alcha­mi joined the UTC-Avenues lab­o­ra­to­ry as a Research engi­neer, after car­ry­ing out an intern­ship at the UTC Rober­val Lab­o­ra­to­ry. She works on PV2E_Mobility but also on the Inter­na­tion­al Ener­gy Agency’s (IEA) PVPS Task 17 programme.

Her pre­cise role on the STELLA plat­form? «I work with Saleh on the exper­i­men­tal part of the charg­ing sta­tions. I car­ry out tests to study var­i­ous recharg­ing pro­files, based on dif­fer­ent cri­te­ria, with the aim of siz­ing the recharg­ing sta­tions in an opti­mal man­ner, so as to best meet demand. The cri­te­ria include the num­ber of elec­tric vehi­cles (EVs) con­nect­ed at any one time, the ener­gy flow and demand, and the dis­charge of EVs to feed the grid dur­ing peak demand. This is called Vehi­cle-to-Grid (V2G),» she says. Her mis­sion does not end there, how­ev­er, as Amalie Alcha­mi is also involved in the PV2E_ Mobil­i­ty project and Task 17 of the inter­na­tion­al IEA PVPS pro­gramme. «In the frame­work of the lat­ter, I have devel­oped a tool for the pre­siz­ing pow­er recharg­ing sta­tions pow­ered by pho­to­volta­ic (PV) pan­els, tak­ing into account Life Cycle Assess­ment. In oth­er words, we have to analyse the per­for­mance of a recharg­ing sta­tion over its entire expect­ed lifes­pan, which in our case is 30 years,» she says. What vari­ables are includ­ed in the tool? «We include the loca­tion of the charg­ing sta­tions, the lev­el of solar radi­a­tion and geo­graph­i­cal con­straints, but also the cost issue. There is the cost of the pan­els, bat­ter­ies and ter­mi­nals, the cost of main­te­nance — clean­ing the PVs, replac­ing bat­ter­ies and con­vert­ers for exam­ple — and final­ly the oper­at­ing costs. So we need to be able to cal­cu­late the total bal­ance, tak­ing into account the income fore­cast over the 30 years,» she says. Envi­ron­men­tal aspects, and in par­tic­u­lar the car­bon foot­print of such charg­ing sta­tions, are nat­u­ral­ly also tak­en into account. «We must reduce this foot­print as much as pos­si­ble in all the ele­ments used, but also inte­grate the foot­print linked to the instal­la­tion and main­te­nance of the sta­tion com­po­nents,» adds Amalie Alcha­mi. Among the avenues of reduc­tion envis­aged? «We can use PV or new gen­er­a­tion bat­ter­ies with a rel­a­tive­ly low car­bon impact; we can also use recy­cled mate­ri­als. With this in mind, we have built sev­er­al sce­nar­ios and we have come up with a charg­ing sta­tion mod­el that has a low­er car­bon impact than the nation­al net­work. The lat­ter, based essen­tial­ly on nuclear pow­er, is already sig­nif­i­cant­ly decar­bonised com­pared to oth­er nation­al net­works,’ she concludes.

Nathanael Dougi­er grad­u­at­ed from IMT Atlan­tique (Nantes) with an engi­neer­ing degree in ener­gy and the envi­ron­ment and went on to defend a PhD the­sis at Arts et Métiers in Aix-en-Provence. He is now inter­est­ed in the ques­tion of future all-elec­tric buses.

What was the core theme of his the­sis? «I worked on micro­grids and more par­tic­u­lar­ly on the dimen­sion­ing of the var­i­ous tech­nolo­gies involved and the asso­ci­at­ed con­trol strate­gies while inte­grat­ing envi­ron­men­tal, tech­ni­cal and eco­nom­ic objec­tives. Let me illus­trate with the case of a city. In con­crete terms, the lat­ter may have objec­tives of auton­o­my, cost reduc­tion or emis­sion reduc­tion. This means choos­ing the rel­e­vant tech­nolo­gies to achieve the right trade-offs between the tar­get­ed objec­tives,» he explains.

His the­sis led to a post-doc­tor­al research posi­tion at the UTC-Avenues lab­o­ra­to­ry. There he works on the IEA’s PVPS Task 17 sci­en­tif­ic pro­gramme and its French con­tri­bu­tion PV2E_Mobility, fund­ed by ADEME.

Among his main tasks? «In addi­tion to my research work, I am assist­ing Manuela Sechi­lar­iu in the project ded­i­cat­ed to Task 17 of the Inter­na­tion­al Ener­gy Agency’s (IEA) inter­na­tion­al pro­gramme. In par­tic­u­lar, this involves par­tic­i­pat­ing in the prepa­ra­tion of the final report which will com­pile the state of research of the var­i­ous inter­na­tion­al teams col­lab­o­rat­ing on this pro­gramme,” he points out. How­ev­er, his role does not end there, as Nathanael Dougi­er is also inter­est­ed in anoth­er mobil­i­ty-relat­ed issue, that of elec­tric bus­es. «With bus­es, we are fac­ing very dif­fer­ent prob­lems from those of elec­tric cars. Indeed, there are major con­straints on bus trans­porta­tion, par­tic­u­lar­ly in terms of con­ti­nu­ity of ser­vice for users, but also in recharg­ing. It is esti­mat­ed, for exam­ple, that an elec­tric car needs a pow­er sup­ply rat­ed at 7 kW for slow charg­ing and 50 kW for fast charg­ing. By com­par­i­son, bus­es in fast charg­ing mode need 600 kW, which is the equiv­a­lent of a hun­dred homes in terms of instan­ta­neous pow­er demand,» he explains.

This is an area that pos­es major chal­lenges, espe­cial­ly in terms of con­straints on the local elec­tric­i­ty grid. «For bus­es, there can be dif­fer­ent ways of charg­ing. For exam­ple, they can be recharged at night at the depot. But this requires them to be equipped with very large bat­ter­ies. They can also recharge for a few seconds/minutes dur­ing the day when they reach the end of the line or at cer­tain bus-stops. How­ev­er, this has an impact on pas­sen­ger trans­porta­tion and the elec­tric­i­ty net­work in the event of a high pow­er demand. This would require the instal­la­tion of new cables, trans­form­ers, etc. So, in the first phase, we need to estab­lish the state of the art in this area,» con­cludes Nathanael Dougier. 

Mathilde Boesch is a final year stu­dent in Urban Engi­neer­ing, spe­cial­is­ing in Build­ing, at UTC. She is in charge of a work­shop-project ded­i­cat­ed to the social accept­abil­i­ty and soci­etal impact of PV (pho­to­volta­ic) pow­ered charg­ing stations.

It was pur­suant to a call for projects from ADEME that this 6‑month project-work­shop — (an “AP”), in which 12 stu­dents par­tic­i­pate — was set up. SHis role as project-work­shop leader? «I update our progress at each ses­sion for the project to the super­vi­sors and set the agen­da for the ses­sion. Then, with the group, we sub­di­vide up the tasks to be car­ried out dur­ing the day,» she says. This study fol­lows suit to a sim­i­lar study car­ried out in 2018. The aim this time is to check whether the mind-set of the French has changed in regard to the con­cept of elec­tro-mobil­i­ty and the use of PV ener­gy, espe­cial­ly as we have seen strong growth in all elec­tric vehi­cle (EV) sales since 2019. It is also a ques­tion of ver­i­fy­ing the accept­abil­i­ty of charg­ing sta­tions with intel­li­gent ener­gy man­age­ment allow­ing a two-way exchange. In oth­er words, an EV can receive stored ener­gy from PVs but also sup­ply its own home, for exam­ple, or the nation­al grid in the event of a con­sump­tion peak,» she believes.

The var­i­ous stages of the study? «We start­ed with a qual­i­ta­tive sur­vey dur­ing semi-direc­tive inter­views with users of EVs but also of oth­er types of trans­port. From the six­ty or so respons­es, we came up with a num­ber of hypothe­ses to be ver­i­fied dur­ing a quan­ti­ta­tive sur­vey with the imple­men­ta­tion of a ques­tion­naire. We want­ed a larg­er sam­ple that was rep­re­sen­ta­tive of the French pop­u­la­tion, and to date near­ly 800 peo­ple have respond­ed,» she explains.

And con­cern­ing the analy­sis of the respons­es? «A ques­tion-by-ques­tion analy­sis and then an over­all analy­sis were car­ried out, fol­lowed by a com­par­i­son with the 2018 study to see if and how men­tal­i­ties have changed. In a way, we are try­ing to find out the state of mind of the French with regard to elec­tro-mobil­i­ty in order to tar­get the obsta­cles and expec­ta­tions rel­e­vant to this tech­nol­o­gy devel­op­ment,» con­cludes Mathilde Boesch.

Le magazine

Avril 2024 - N°62

Faire face aux enjeux environnementaux

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