No lemonade tree, no red-haired girl, and no speckled horse on the porch. The 20-year-old home in the south of Munich really doesn’t look like Villa Kunterbunt. Nevertheless, Astrid Lindgren’s nursery rhyme can be heard: “I make the world the way I like it …” Like Pippi Longstocking, Karlheinz Seim also likes to be self-sufficient, especially when it comes to climate protection. Instead of a grazing four-legged friend, there is an electric car in its driveway. The electricity comes from your own roof or from the fuel cell in the basement. But what does such an eco-idyll cost? Do you need a box full of gold like in a children’s book?
It works out for Karlheinz Seim. He has invested a lot of time and money in his personal energy transition. In return, he saves almost 2,000 euros in petrol costs per year and as much money again on heating and electricity. The “Project Seim” has already paid for itself after seven years – but can something like this work on a larger scale? Proponents and opponents of the European “Green Deal” accuse each other of living in a (green) dream world. When the EU Commission proposed a combustion ban for 2035 last week, scientists went on the barricades and politicians went mad.
Last but not least, it is about the carbon footprint of electric cars: This is bad, warn critics, because the production is much more energy-consuming than with combustion models. “To produce one kilowatt hour of battery capacity, you need around 80 times as much energy,” confirms Peter Carlsson, head of the cell manufacturer Northvolt. At the end of this year, climate-friendly cell production is due to start in Skellefteå in northern Sweden, which is rich in hydropower. Critics complain that most batteries are made in Asia using coal. The fact that German car manufacturers (and many others) have now thundered their cell suppliers to green electricity is drowned out in the turmoil. So is Karlheinz Seim’s BMW i3 a secret climate killer? High time for a fact check in the Munich bacon belt.
Karlheinz Seim worked on his very personal energy transition for ten years. Now he is planning an Ickingen neighborhood solution with like-minded people.
(Photo: private)
The now 72-year-old self-sufficiency felt like many other electrical pioneers: First came the photovoltaic system, then the e-mobile. Solar farmers start pondering at the latest when their solar collectors are no longer subsidized by the state. Compared with the electricity costs of up to 30 cents per kilowatt hour (kWh), there is only small change for the energy fed in. The problem: The BMW i3 no longer releases the stored energy, for example to stabilize the grid or to illuminate your own house. For the latter, a stationary energy storage device must be purchased in addition to the mobile one. That drives up the costs by a few thousand euros.
The individual energy transition quickly encounters technical hurdles. Who can couple the domestic producers, storage systems and consumers not only with one another, but also with the network services of the energy suppliers as required? The search for the appropriate control electronics cost even the IT experts Seim time and nerves. Networking with neighbors is more efficient than a purely private solution: Karlheinz Seim is currently working with like-minded people to interconnect 300 Ickingen PV roofs via a central power storage system. Such a professional neighborhood solution would make the additional batteries in the home superfluous. The relatively large energy stores in electric cars only play a passive role. Is there more? Could a networked vehicle pool replace the expensive central storage? And how would the network connection work?
The regulation of power grids is complicated enough. With the increase in wind and solar power, it becomes even more complicated
Kilowatts here, gigawatts there: There are still worlds between the Ickingen project and large-scale industrial power generation and transport. The lack of storage capacity in the network is a particular hindrance to the expansion of volatile green electricity. “For example, the wind power can fluctuate between zero and 10,000 megawatts in a few hours. This makes the storage issue central,” says Ferdi Schüth, Director at the Max Planck Institute for Coal Research and Vice President of the Max Planck Society. In Germany, the storage capacity is sufficient for around 20 minutes of the energy requirement, then the pumped storage power plants are empty, says Schüth, “and there is hardly any chance of expanding it.”
The solution may be on the street: If thousands of electric cars could be interconnected to form a large virtual storage system, no additional (coal) power plant would have to be activated. The Stromer could stabilize the grid and maximize the share of renewable energies in it. However, the technical hurdles are high: energy self-sufficiency with your own charging plug is one thing. It is a different matter when the polarity of the charging direction in entire fleets is reversed at lightning speed, for example to buffer a lull in the wind on the North Sea.
The networked house and car in the energy system: the logo of the bidirectional charging project (BDL)
(Photo: BMW)
“In the transport networks, it takes a few seconds to regulate the system across so many instances. This is a real-time system, so to speak,” explains Xaver Pfab, BMW project manager for bidirectional network integration (vehicle to grid, V2G for short). There is still neither an automotive series solution for the bidirectional network connection nor the correspondingly proven control systems at the network operators, let alone a legal framework for it.
“There are currently 86 V2G projects worldwide. Apart from us, there is not a single project that deals with questions of energy law. But this will be a very important point for the legislature in the future,” said Pfab. No less important is the question of how you can incentivize electric vehicle enthusiasts to change their charging habits. For example, not to start tapping the power when you get home in the evening. Because then the network is already at its limit. In addition, drivers not only have to share their electricity, but also (anonymized) data. For example, when you want to start with which energy supply in the car the next morning.
Xaver Pfab has been dealing with bidirectional charging for many years: “When we tested a small series of 500 mini-e-vehicles worldwide in 2009, we didn’t scrap them after the end of the project, but rather 60 vehicles from the University of Delaware for one of the first “V2G” projects made available. ” Reversed to bidirectional charging, 16 vehicles were then hung up day and night in control power mode on the public power grid. “It didn’t damage the batteries,” said Pfab. In 2015, the ChargeForward pilot project was started in California. Around 100 drivers were able to flexibly control the charging process of their BMW i3 using a mobile phone app. In order to avoid said consumption peaks in the network.
So far, the energy industry and the automotive industry have not had much to do with each other. Several universities and power grid operators are researching how this sector coupling can work in the latest v2G project under BMW management. “In ambitious climate protection scenarios, we will already have 20 million electric vehicles in the system by 2035,” says Wolfgang Mauch, Head of the Research Center for Energy Economics (FfE): “Assuming a storage capacity of 50 kWh per vehicle, that corresponds to 1000 GWh storage capacity. That is more than 20 times as much as all German pumped storage power plants put together. “
That sounds good, but it is only a theoretical value: the wall boxes on which the e-vehicles are usually attached do not have more than ten kW connected load. Each Stromer can only provide part of its energy reserves. That saves the battery – and it would still be enough to buffer peak loads in the German network. For this purpose, BMW, the research institutes and network operators have developed new communication interfaces and a bidirectional charging station. The first 20 BMW i3s with the regenerative charging technology are now being tested under real-life conditions. By the end of the year there should be 50 vehicles. This is more than a motley children’s dream, especially when bidirectional charging goes into series operation.