How can local power grids be protected from overload when millions of electric cars are being charged and electric heat pumps are running? With "network-oriented control", says the Energy Industry Act recently. But how is that supposed to work? The rules have been the subject of controversial debate for weeks. Critics warn against throttling for heat pumps and wall boxes. It is already clear: the rules could have consequences for millions of electricity consumers. They are to apply from January 2024.
What the problem is
Electricity consumption in Germany will increase significantly in the coming years. In the transport sector, millions of e-cars are to help achieve climate targets, and millions of heat pumps are to be installed in buildings.
However, this rapid increase in new consumers poses major challenges for the power grids, as stated in a statement by the German Energy Agency to the Federal Network Agency. In particular, the low-voltage grids are usually not designed for peak loads that could occur if these new consumers draw electricity at the same time. Network expansion is necessary, but it takes time, costs a lot of money and requires many specialists, who are rare at the moment.
What the planned solution looks like
So that the ramp-up of electric cars and heat pumps is not held up by capacity bottlenecks in the electricity distribution network, network operators should avoid such bottlenecks through control. That's what it's all about. After the new version of the Energy Industry Act, the Federal Network Agency can make nationwide regulations for this.
In November, the network agency presented the first key points. It states that the distribution network operators should be given the opportunity to intervene if necessary - in order to be able to maintain secure network operation. At the same time, however, they should only control as much as is absolutely necessary in order to restrict the "comfort" of the customer as little as possible. It is about a temporary reduction in the amount of electricity purchased from the grid. The consideration for consumers: a flat-rate discount on the network fee.
Controllable heat pumps, private charging stations and electricity storage should then be operated above all when the electricity price is low due to high feed-in of renewable energies. The controllability should enable network operators to avoid bottlenecks and thus local power failures.
What does that mean in concrete terms for consumers?
If a bottleneck is imminent, according to the Federal Network Agency's concept, wall boxes, for example, should be able to be throttled down to an output of 3.7 kilowatts in order to prevent overloading. The German Association of the Automotive Industry (VDA) expects the charging time for e-cars to be three times as long and warns of "considerable losses in comfort" and even usage restrictions.
The Federal Association of Heat Pumps says that there are already voluntary agreements to switch off heat pumps for peak compensation for up to two hours - without any loss of comfort for households. According to the key points of the Federal Network Agency, however, this should become mandatory. The association complained that there were still no detailed specifications. According to the manufacturers, many existing heat pumps cannot be technically reduced to an output of 3.7 kilowatts. They would then automatically turn off completely.
What the auto industry and others are demanding
An alliance of the Federal Association of New Energy Industry, the Federal Association of Heat Pumps, the VDA and the Federal Association of Consumer Organizations fears significant restrictions for consumers. Upper limits are necessary for "emergency chokes" and additional measures to preventively avoid network overload - for example time-variable electricity tariffs. "Consumers then benefit financially if they shift their charging processes to off-peak times when network utilization is low," says a VDA spokesman. Direct control interventions by the network operator should only be a last resort.
Lion Hirth, energy expert at the Hertie School in Berlin, recommends incentives to charge when there is space in the grid. The prerequisite is that Germany finally makes decisive progress in digitizing the electricity system. "You need intelligent measuring devices that can also transmit this in real time. Germany is spectacularly bad here in international comparison."
What the energy industry says
The VDE Association for Electrical, Electronic & Information Technologies (VDE) rejects the coalition's criticism that network operators are allowed to throttle devices "unilaterally and indefinitely" in the event of an impending network overload. Customers knew from the start that they could be affected and received financial compensation in the form of a reduced network fee - regardless of whether they were actually affected by control measures as a result.
"Unlimited throttle" is not given. There are minimum limits that should not be undercut and allow customers to continue to operate their normal electricity consumers. "Even charging an e-car is possible with it, albeit with reduced power and thus a longer charging time," according to the VDE.
The Federal Association of Energy and Water Industries also considers the concern that consumers could not be supplied with electricity at times to be unfounded. The planned regulation only applies to households that have installed a wall box or a heat pump, said general manager Kerstin Andreae. The household itself remains unaffected by a possible short-term dimming. "Fridge, washing machine and internet continue to work as before."
Network expansion is still the top priority. "The possibility of short-term dimming is an ultima ratio measure until the network is adapted to the new demand." The selective control does not replace the network expansion, but rather guarantees the security of supply in the short term.
How it goes on
This Thursday there will be a public hearing at the Federal Network Agency, in which the disputed points will be discussed again. In the second quarter, the authority then wants to publish a concrete draft regulation. Afterwards, all those affected can comment again. In autumn, the authority then wants to present the final regulation, which should apply from January 2024.