Private car ownership is ridiculously wasteful

Here’s a question: how big is the entire power plant fleet in your country compared to the fleet of vehicles? Craig Morris investigated the matter for Germany. Before you read on, take a guess: which one is bigger?

Two out of three cars would disappear from this picture if we switched to car-sharing (Photo by De-okin, edited, CC BY-SA 3.0)

Germany’s private car fleet is some 40 times bigger than its entire conventional power fleet: 4,300 GW vs. 107 GW. And while these power plants run at around half of their rated capacity over the year, cars are only used on average an hour a day – and their motors are vastly overpowered for the tasks they generally perform.

A capacity factor (CF) reflects how much energy a unit produces relative to how much it could if running full-blast. The German power plant fleet runs at around half capacity (48%), and that number is even dropping because wind and solar are offsetting conventional power faster than plants close. Critics of renewables say this trend is wasteful, but less fossil and nuclear power is the goal of the Energiewende, not some unintended, undesirable outcome.

If you want to criticize wastefulness, private car ownership is clearly a low-hanging fruit. Private cars are currently only used for around one hour a day. And they have vastly oversized engines; the average in Germany is around 128 horsepower (in German). We use a small fraction of that capacity to creep through our cities at an average of 30 km/h.

People don’t buy cars for everyday purposes. They buy them for outlying needs. We thus choose big engines, say, to haul heavy stuff even if we rarely do so. Families buy station wagons (as I, ahem, know from personal experience…) for those bimonthly family trips with luggage, but then the cars are used on a daily basis for something else: driving one parent to work alone.

Admittedly, comparing cars and power plants is a classic case of apples and oranges. Cars are power plants aren’t even used for the same thing; no one is suggesting that private cars running on diesel or gasoline should be used to generate electricity. On the other hand, the CF of these cars is much lower than the 4% shown above – that’s just the one hour a day those cars are used. But even then, those engines are not running at full capacity; people rarely put the pedal to the metal. In reality, the capacity factor of privately owned cars is probably below one percent. It’s ludicrous.

So what’s the answer?

Lots of my readers are probably thinking, Craig, I can’t do without my car. I get that. Not everyone has good public transport, and in places like Berlin (a pretty car-friendly city, if you ask me) taking a car can be more convenient than taking a bus or tram.

Private car ownership is the main problem. A recent study by Germany’s Environmental Agency (UBA) found that German cities could do away with two thirds of cars if the entire fleet were shared. That change along would bring the fleet’s collective motor size down to 1,400 GW, “only” some 14 times greater than the current conventional power fleet in Germany. And everyone would ideally be able to pick the car they need for each trip, so we could downsize lots of motors, improving efficiency even further. (That’s the problem with Tesla’s “ludicrous mode” (video): the cars still have oversized engines. But at least we can agree it’s ludicrous.)

If the shared car fleet were also electric, even greater advances would be possible. We’d no longer be comparing apples and oranges: these cars would be connected to power plants. They would eventually run on excess wind and solar power (which Germany doesn’t yet have), and while stationary (so most of the time) shared EVs could help stabilize the grid by providing ancillary services.

By switching to a fleet of shared electric cars, we could increase our resource efficiency massively, even as we provide solar and wind space to grow further. We would also dramatically reduce the number of cars clogging up our streets. I’m not talking about traffic jams, but the excessive number of cars parked on our streets 23 hours a day.

Increasingly, Germans are becoming aware of the free ride we give privately owned cars. I close this article with a wonderful video (unfortunately, only in German) from Deutsche Welle. The narrator is taking back her street so it can be used by people. She argues that everyone pays for free parking spaces through taxes, so everyone should get to use them, not just car owners. So shared fleets of EVs it is!


Craig Morris (@PPchef) is the lead author of Global Energy Transition. He is co-author of Energy Democracy, the first history of Germany’s Energiewende, and is currently Senior Fellow at the IASS.


Craig Morris (@PPchef) is co-author of Energy Democracy, the first history of Germany’s Energiewende.


  1. There is a tricky messaging problem here. Advocates for the energy transition have spent years trying to disabuse the average Joe and Jane that they are not hairshirt killjoys lecturing them to Repent and be Saved. Instead, renewables are something that allows John and Jane to live the life the want, without wrecking the climate, their neighbours’ health, or their family budget.

    The same holds for car-sharing, cycling and public transport. Switching to more of them is a good idea, and software plus electric cars will make it more attractive. But making people feel guilty about having a private car is not the way to go. The only shaming should be about internal combustion engines. The case for congestion charges to dissuade the use of private cars (or whatever power source) is technocratic, not ethical.

    Incidentally, we don’t know what the optimum mix of vehicle types would be in a rideshare city. It might be dominated by four/five-seater cars as now, plus 50-seat buses on fixed routes, or it might be led by ten-seater jitneys operating as shared taxis or on semi-fixed routes. This should not become a moral argument either. Let the congestion charges correctly reflect road occupancy, and the market and software developers will sort it out.

  2. S. Herb says

    Unmentioned here is the additional dimension of urban planning and (an oxymoron, in the US?) suburban planning to reduce the need for auto trips (and parking). We have really boxed ourselves into our auto-centric system; there are undoubtedly alternative urban and suburban neighborhood models which many people would find attractive but it’s not easy to get there from here. Congestion charges and the like should be accompanied by a political will to encourage experiments.

  3. Vivi says

    In my opinion, the problem in Berlin is the cost of public transport tickets, not the system’s spatial / temporal convenience. When I was a student, we all had a prepaid semester ticket that enabled us to use ALL public transport options in Berlin and close surroundings (including most importantly the dense trains and subway system – Who the hell uses busses and trams to get around Berlin?! Those are just for the last few hundred meters from the closest train station.) And due to collective bargaining for several thousand guaranteed purchases, that 6-months-ticket was considerably lower in cost than similar options for the general public. (It came out to the equivalent of something like 3 or 4 of the standard 2-hour-tickets per week. And I for one would have needed at least 10 of those per week if not for the long-term ticket, plus extra for those occasional 1-hour-trips for mid-day lecture room changes due to the university campusses being scattered all around the city. Students with less demanding schedules who actually had enough time left for a social life would have needed even more.) The students from West German states who’d had cars bought for them by their parents and perhaps weren’t used to usuing public transport during their high school days usually moaned and complained at first about being forced to buy a public transport ticket they wouldn’t use much (the ticket alone was like 70% of the overall semester fees since all Berlin universities offered free tuition; it wasn’t possible to opt out of the system individually but there was a social slush fund contributed to by all students for those few hardship cases who really couldn’t afford to pay for the ticket) – but within a few months, they too realized just how damn convenient it is to just be able to jump on every one of those once-every-10-minutes trains without ever having to think about stamping tickets or looking for parking space, since bicycle transport was included. And you don’t have to pay car insurance, of course. And while the trains are very crowded during rush hours and have an intrusive busker/beggar problem on some lines, you often can use the idle time to do your homework, instead of having to concentrate on traffic.
    I heard that the student body of the West Berlin Freie University (richer parents, on average, partly due to the “villa quarter” location, partly due to the focus on social sciences and law) actually voted to opt out of the system one year, condemning its poorer students (unable to afford cars) to buy the regular commercial tickets. And teaching every other student how much higher the general public prices are, when they wanted to go out at night and get drunk, for example. As far as I remember, they joined the other student body associations in collective bargaining again the next year.

    So, what Berlin needs is not so much a more extensive public transport system (though one that’s not constantly under repairs in places would help – though that’s perhaps impossible in a city this big), but rather one that’s more affordable. Either make the public transport companies public property again to stop the ever-increasing price-gounging they’ve been involved in these last 15 years, or institute some sort of heavily subsidized ticket for socially disadvantaged people. Or perhaps found some sort of collective bargaining club for non-student customers as well.

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