Drive Electric

E.ON study: Smart equip­ment, such as volt­age reg­u­la­tion dis­tri­b­u­tion trans­form­ers, can ensure that grids are able to cope with peo­ple charg­ing their elec­tric cars.


Marten Bun­ne­mann is the CEO of Ava­con AG. He is con­vinced that VRDTs are the way for­ward when it comes to over­com­ing the chal­lenges asso­ci­at­ed with e‑mobility.

Elec­tro­mo­bil­i­ty is on the rise all around the world. But this rais­es the ques­tion whether our pow­er grids can cope with this trend. E.ON, Germany’s largest dis­tri­b­u­tion grid oper­a­tor, recent­ly pub­lished a high-pro­file study look­ing into the grids of its four region­al grid oper­a­tors (Ava­con Netz, Bay­ern­werk Netz, E.DIS Netz, and Schleswig-Hol­stein Netz). And the results con­firmed that it would be pos­si­ble to charge all cars elec­tri­cal­ly with­in the area served by the grids by 2045.

Volt­age reg­u­la­tion dis­tri­b­u­tion trans­form­ers (VRDTs) are an impor­tant part of the tech­ni­cal infra­struc­ture required. Lead­ing the way in the use of this equip­ment, which was devel­oped in part­ner­ship with Maschi­nen­fab­rik Rein­hausen, Helm­st­edt-based Ava­con Netz GmbH has a par­tic­u­lar­ly impres­sive reper­toire of expe­ri­ence in terms of imple­men­ta­tion and oper­a­tion. We talked with CEO Marten Bun­ne­mann about what the study cov­ered and the tech­ni­cal solu­tions

Mr. Bunnemann, what do you see as the main problems when integrating electromobility into the grid?

All of our research into grid inte­gra­tion has revealed that the main prob­lem is how dri­vers will go about charg­ing their vehi­cles since we have to pre­dict these pat­terns of behav­ior 15 or 20 years in advance. The key ques­tions to con­sid­er are: How many cars will real­is­ti­cal­ly be charged at once and how can we make sure that the grids are able to cope with this lev­el of demand? We looked into this as part of the large-scale study men­tioned above, but also in many oth­er stud­ies. We gave par­tic­u­lar empha­sis to those look­ing at rur­al grids since our rur­al spaces (vil­lages and small and medi­um-sized towns) have the most cars.

Propo­si­tion one:
A full switch to e‑mobility is a pos­si­bil­i­ty

And we deter­mined that, on the basis of the knowl­edge avail­able to us now, there won’t be any major prob­lems for our grids if we are smart in our prepa­ra­tions for elec­tro­mo­bil­i­ty and stay ahead of the game. We want to be able to stand out from the crowd and not force spe­cif­ic charg­ing times on our cus­tomers. They should all be able to charge their vehi­cles at home when­ev­er they wish to. This is the promise we have made to our­selves.

To what extent do voltage regulation distribution transformers (VRDTs) feature in your plans for the upgrade work required in the future?

Trans­form­ers and lines are known for being the main com­po­nents of pow­er grids. Accord­ing to our find­ings, prob­lems main­ly occur in the trans­form­ers and lines in the low-volt­age grid, which is the part of the grid that is clos­est to the cus­tomers. Here, the first prob­lems that almost always arise are trans­form­ers being overload­ed and line volt­ages being too low. Any oth­er issues are much less com­mon.

What this means is that we will replace small, unreg­u­lat­ed trans­form­ers with larg­er volt­age reg­u­la­tion dis­tri­b­u­tion trans­form­ers (VRDTs). And we will also make them intel­li­gent. This large­ly cuts out the need for line rein­force­ments, which often used to be required to the detri­ment of the gen­er­al pub­lic.

A lot of demand would be placed on the pow­er grid if every­one were to start charg­ing their cars at the same time. VRDTs help to keep the volt­age con­stant. (© Timo Müller)

What benefits do you expect from the use of voltage regulation distribution transformers?

To put it sim­ply, the use of VRDTs large­ly rules out volt­age prob­lems in the low-volt­age grid, and poten­tial­ly also the medi­um-volt­age grid, depend­ing on the spec­i­fi­ca­tions. This is a very quick and effi­cient way of ensur­ing that we don’t have to sub­ject the gen­eral pub­lic to unnec­es­sary cable in­stallation work.

Propo­si­tion two:
There are no longer any tech­ni­cal obsta­cles stand­ing in the way of full e‑mobility.

Instead, we can lim­it our­selves to work that is usu­al­ly required as a result of age and to major new con­nec­tions that have always required grid devel­op­ment. This is how we can fit elec­tro­mo­bil­i­ty into the exist­ing grid—especially when we are able to look ahead and make plans for the future.

But we mustn’t for­get that costs are still involved. We includ­ed cost con­sid­er­a­tions in our study with the results show­ing a one-time charge of around EUR 400 on aver­age per vehi­cle for expand­ing the grid. But as far as we are con­cerned, these invest­ments are absolute­ly worth­while. It’s all rel­a­tive, after all: Around EUR 25,000 has to be invest­ed in a car every sev­en years on aver­age.

Which specific measures does the study call for?

Per­haps we should cov­er one thing first of all: We are often asked why we assume that the auto­mo­tive seg­ment will become ful­ly elec­tric. We know that this is a bold assump­tion but it is based on inter­nal and exter­nal analy­ses of the mobil­i­ty sec­tor, with a par­tic­u­lar focus on sus­tain­abil­i­ty and effi­cien­cy. The cru­cial thing for us is what we now take away from the results. And we have to say that we have put togeth­er an excel­lent pack­age.

Propo­si­tion three:
Grids can be made fit for the future with­out hav­ing to under­go major restruc­tur­ing.

What this means for our cus­tomers and com­mu­ni­ties first off is that we will be sup­port­ing elec­tro­mo­bil­i­ty in every way. Instead of com­plain­ing, we’ll be moti­vat­ing because we believe this is the right direc­tion to be head­ing in and we take the issue of CO2 very seri­ous­ly. As far as our grids are con­cerned, we will be focus­ing on intel­li­gent sec­ondary sub­sta­tions with VRDTs and on larg­er line cross-sec­tions. But this will only be when replace­ments are need­ed, usu­al­ly owing to age. This requires an incred­i­bly strate­gic approach when allo­cat­ing expan­sion work but it stops us press­ing pause on a future issue that we don’t want to aban­don.

The ECOTAP® VPD® is the key com­po­nent in the quest to have e‑mobility rolled out exclu­sive­ly. (©Timo Müller)

That was sad­ly what many grid oper­a­tors did ten years ago when the first solar boom occurred before this VRDT tech­nol­o­gy even exist­ed. And we don’t want to be faced with an impos­si­ble task in ten years’ time. Anoth­er point worth mention­ing is that we will also have more solar pow­er with­in our grids, poten­tial­ly includ­ing heat pumps, and VRDTs are ide­al here. This tech­nol­o­gy there­fore helps move the ener­gy tran­si­tion in all direc­tions.

VRDTs are still quite rare around the world. What’s your experience with using them?

Our oper­at­ing expe­ri­ence has been very pos­i­tive. It goes with­out say­ing that there were a few start-up and devel­op­ment prob­lems with the first series deliv­ered years ago. But the VRDTs we have today work in exact­ly the same way as stan­dard trans­form­ers. But, fig­u­ra­tive­ly speak­ing, they can do twice as much!

Propo­si­tion four:
VRDT tech­nol­o­gy is key to the ener­gy rev­o­lu­tion.

And there is not even much more mate­r­i­al required—just the reg­u­la­tor. For us this means effi­cien­cy, intel­li­gence, and sus­tain­abil­i­ty. Obvi­ous­ly all of that can­not replace strat­e­gy and exper­tise, includ­ing on the part of col­leagues work­ing on the grid. But our expe­ri­ence has been so pos­i­tive that over 90% of our new trans­former acqui­si­tions in 2019 have been VRDTs.

REINHAUSEN INSIDE

A full switch to elec­tro­mo­bil­i­ty rep­re­sents a major chal­lenge for dis­tri­b­u­tion grids—especially if the pow­er has to come from sus­tain­able sources. The tech­nol­o­gy needs to com­pen­sate for fluc­tu­a­tions in medi­um volt­age and must be able to respond dynam­i­cal­ly to changes in feed-in and load at the low-volt­age lev­el. In both cas­es, grid oper­a­tors can rely on the ECOTAP® VPD®.

It com­bines the exper­tise that MR has accu­mu­lat­ed over decades of work­ing with vac­u­um on-load tap-chang­ers in high-speed resis­tor-type tap-chang­er tech­nol­o­gy with expe­ri­ence in volt­age reg­u­la­tion dis­tri­b­u­tion trans­form­ers to guar­an­tee a sta­ble, main­te­nance-free per­for­mance of 500,000 tap-change oper­a­tions. The ECOTAP® VPD® is so com­pact that it does not make the dis­tri­b­u­tion trans­former any larg­er.


YOUR CONTACT


Do you have ques­tions?
Armin Viel­hauer is here to help:
A.Vielhauer@reinhausen.com


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