Germany must address potential bottlenecks in its distribution grid ahead of an expected surge in electric vehicle (EV) sales, delegates heard at an event organised by the opposition Green Party last week.
The country's EV registrations are expected to reach 1mn this year, and some first-time owners are being told by their local grid operator that they will need to wait before installing a wallbox because of grid constraints, automotive association VDA president Hildegard Muller said.
Strong EV sales are of vital interest to Germany's automotive industry, and the sector will face stiff fines if it misses its emissions targets because potential EV buyers are put off by the possibility of not being able to charge their car when they want to, Muller warned. "We cannot tell our customers 'you need to negotiate with your grid operator'," she said.
The federal economy and energy ministry is working on a "law on controllable facilities" that will seek to to ensure the extension of the grid as cost-efficiently as possible by incentivising demand-side flexibility. But a draft was withdrawn in January after the VDA and consumer and renewables associations attacked its "one-sidedness", for suggesting giving distribution system operators (DSO) the right to curtail power flow to EV charging points at certain times to prevent grid overload.
Economy and energy minister Peter Altmaier recently pledged to instead look at solutions modelled on demand-side management rules. The law is due to be passed before parliament's summer break.
Germany's energy industry, and the power grid sector in particular, had welcomed the draft bill, which they said was not about "cutting off" EVs, but about the possibility of DSOs lowering power flow — to "dim it, so to speak", energy and water association BDEW's managing director, Kerstin Andreae, said.
Variable tariffs — as suggested by the VDA — will only be possible once digitalisation has advanced sufficiently, and they could defeat their purpose if households shift their consumption to the same "cheap" times, Andreae warned.
The level of digitalisation in Germany's low and medium-voltage systems is far too low to allow DSOs to know "what is going on in their grids", DSO Stromnetz Berlin's chief executive, Erich Landeck, said. DSOs are tackling this, but it will take time, Landeck said. And most EVs do not yet offer bidirectional charging, so cannot discharge power back into the grid.
It is also too early for EVs or heat pumps to contribute to grid stability outside special projects, Landeck said.
State intervention
Restructuring the distribution grid should be an "infrastructure task for the state", VDA's Muller said. She also urged policy makers to rapidly establish a standard for EV charging points. The fact that most cannot be steered remotely is unacceptable, she said.
The government should act beyond subsidy programmes, Muller said. The federal transport ministry on 26 February announced that state-owned bank KfW received 300,000 funding applications for private wallboxes in three months, and that the ministry will top up the programme with an additional €100mn ($120mn). "But the problem runs deeper," Muller said.
The Green Party's energy economy spokeswoman Ingrid Nestle suggested initially leaving things unchanged, and simply monitoring existing "hotspots" with high EV penetration, where DSOs could implement ad hoc measures.
But Muller rejected this, saying it will be years between the DSOs defining a specific need and completion of the necessary grid upgrade.
A daily "intervention time" of two hours, is the minimum needed to have an effect on grid stabilisation, giving drivers 22 hours per day of potential charging time, northwest German system operator EWE Netz's head of grid management, Michael Westerburg, said earlier this year. Even charging for just two hours per day, at a capacity of 11kW — the typical home-charging capacity — would allow the average car to cover 40,000km per year, Westerburg said.
