Image: h_da/Ingo Jeromin

Opti­mized ener­gy sup­ply: Grid4Regio project aims to make bet­ter use of exist­ing grid infrastructure

Ener­gy is more expen­sive than ever. In the course of the ener­gy turn­around and the cur­rent polit­i­cal sit­u­a­tion, the expan­sion of renew­able ener­gies is intend­ed to con­tribute to cli­mate pro­tec­tion, but also to make us eco­nom­i­cal­ly less depen­dent on fos­sil fuels. How­ev­er, espe­cial­ly in the case of wind and solar ener­gy, grid bot­tle­necks are cur­rent­ly still pre­vent­ing opti­mal use of the ener­gy gen­er­at­ed. In the EU-fund­ed research project “Grid4Regio”, Darm­stadt Uni­ver­si­ty of Applied Sci­ences (h_da) is work­ing togeth­er with e‑netz Süd­hessen AG and Darm­stadt Tech­ni­cal Uni­ver­si­ty to bet­ter exploit the poten­tial of exist­ing grid infra­struc­ture at region­al lev­el, to relieve the trans­mis­sion grids …

… and thus coun­ter­act the some­times con­tro­ver­sial grid expansion.

The Bin­sel­berg near Groß-Umstadt on the edge of the Oden­wald. Four large wind tur­bines gen­er­ate ener­gy here, which is fed direct­ly into the region­al pow­er grid. So far, so good. But what hap­pens on days when the wind tur­bines gen­er­ate more ener­gy than the grid can absorb on site? Cur­rent­ly, due to a lack of stor­age options, either the loss of pre­cious ener­gy must be accept­ed or the sur­plus ener­gy is “pushed up” into the upstream high-volt­age grid. Prof. Dr. Ingo Jeromin from the Depart­ment of Elec­tri­cal Engi­neer­ing and Infor­ma­tion Tech­nol­o­gy at the h_da calls this the “ener­gy highway”.

Accord­ing­ly, the region’s medi­um-volt­age grid is the inter­state high­way and the high-volt­age lev­el is the free­way. If, dur­ing increased traf­fic on the fed­er­al high­way, every­one briefly takes the sup­pos­ed­ly faster route via the free­way and then the exit again in the direc­tion of their des­ti­na­tion, a traf­fic jam occurs at the inter­change. If con­ges­tion per­sists, in many cas­es the high­way net­work is expand­ed ‑the same is true of the pow­er grid. In the end, both mean: addi­tion­al costs for taxpayers.

Prof. Dr. Ingo Jeromin is con­vinced that this does not have to be the case. Togeth­er with his project part­ners, he wants to show that by using new tech­nolo­gies and sys­tems, renew­able elec­tric­i­ty can not only be gen­er­at­ed on site, but also con­sumed direct­ly. “Why build new elec­tric­i­ty high­ways when you can use the exist­ing, pass­able fed­er­al high­way? With our project, we want to help find a solu­tion to keep the expan­sion of renew­able ener­gies and the asso­ci­at­ed costs as low as pos­si­ble by using the exist­ing ener­gy as effi­cient­ly as possible.”

In con­crete terms, this means that the “sur­plus” regen­er­a­tive ener­gy from wind and sun in the medi­um-volt­age grid in the Groß-Umstadt region is to be redis­trib­uted to oth­er com­mu­ni­ties in the region, such as Baben­hausen or Groß-Bieber­au, instead of being fed into the upstream high-volt­age and extra-high-volt­age grids and thus bur­den­ing them. The idea of the research team: Neigh­bor­ing net­works are to be cou­pled in a decen­tral­ized man­ner using already exist­ing infra­struc­ture in order to make the best pos­si­ble use of it. The mod­el region in which this approach is being inves­ti­gat­ed is in the net­work area of e‑netz Süd­hessen AG, which ini­ti­at­ed the project.

The h_da Research Group for Sus­tain­able Ener­gy Sys­tems (daFNE) led by Pro­fes­sors Ingo Jeromin, Athana­sios Kro­n­tiris and Klaus Mar­tin Graf plays an impor­tant role in the project. By means of a net­work con­trol cen­ter sim­u­la­tor designed at the h_da, con­crete usage sce­nar­ios are to be run through and then trans­ferred into a train­ing and edu­ca­tion con­cept for spe­cial­ists from the ener­gy and net­work indus­try, e.g. employ­ees of dis­tri­b­u­tion net­work oper­a­tors. These sce­nar­ios are based on the research results of the depart­ment “Elec­tri­cal Ener­gy Sup­ply Using Renew­able Ener­gies” at the TU Darm­stadt, head­ed by Pro­fes­sor Jut­ta Hanson.

“In order to be able to map the con­di­tions in the region cor­rect­ly, we first have to under­stand the net­works and the var­i­ous usage sce­nar­ios cor­rect­ly,” says Prof. Dr. Ingo Jeromin, describ­ing the chal­lenge. “Due to new influ­enc­ing fac­tors such as elec­tro­mo­bil­i­ty or the increased use of heat pumps, a lot is chang­ing right now in terms of grid usage by end con­sumers. With these unknown vari­ables, it is cur­rent­ly still dif­fi­cult to calculate.”

The sim­u­la­tion of the net­work sys­tem of the mod­el region and the asso­ci­at­ed cross-con­nec­tion con­trol cen­ter of e‑netz Süd­hessen AG, which is avail­able in the com­put­ers of the researchers, helps here. “We would like to devel­op a kind of blue­print for Ger­man medi­um-volt­age grids and pos­si­ble load sit­u­a­tions on the basis of the data sup­plied by the TU on our mod­el region, so that we can use it to cre­ate real­is­tic sched­ules for var­i­ous sce­nar­ios,” Jeromin explains. “In the future, switch­mas­ters through­out Ger­many could thus be able to assess in their region­al con­trol rooms which switch­ing oper­a­tions are nec­es­sary to avoid over­load­ing train path XY.”