- 100% renewables is hard. 90% renewables is straightforward.
- electric cars generally charge at night and use about the same amount of power as an electric oven. Distribution network changes are not required.
I believe most wind power curtailment today happens overnight.
TANSTAAFL
My point isn't that fuel taxes pay the full costs of the road, but that electric cars in many countries receive favourable taxation (which significantly reduces the cost of ownership) which is only possible because they are a minority of vehicles.
This actually depends largely on the country you're in. In the UK (where I live) the effective tax rate on gas is around 68%, and there's lots of tax breaks for electric cars. The effective tax rate on electricity is 5%, and the cost per MJ of electricity and gas is about the same. Effectively the government tax revenue per mile of electric cars is drastically lower than that of gasoline cars - not a sustainable situation for widespread adoption.
It looks like the tax on gas in the US is significantly lower than in European countries, so the same situation probably doesn't exist to the same degree.
> electric cars generally charge at night and use about the same amount of power as an electric oven. Distribution network changes are not required.
Yes, average power consumption is quite low. In fact over a year the average car (if it was electric) would probably only consume a few hundred watts.
But that's not the problem. The problem is peak demand. A usable electric car charger draws 7kW for a sustained period of time. That's a very different use case (distributed across every house in the country) than currently.
Taking this study for example: "32% of low voltage (LV) feeders (312,000 circuits) will require intervention when 40% - 70% of customers have EVs, based on 3.5 kW (16 amp) charging." http://myelectricavenue.info/
Bear in mind that's for 3.5kW charging, whereas anyone installing a charger today is putting in 7kW+ charging.
The only way to mitigate distribution network changes is by smart charging on the car side - basically reducing charging rate or times to spread the load. Fortunately that's fairly doable, but it's not necessarily a panacea - if there's a couple of days where many people do higher than average mileage (eg a national holiday) you could find that there's simply not enough capacity locally to sustain charging all the cars on the street.
The problem is that we need to be adopting electric cars _now_ to make a dent in emissions, but there's all these infrastructure problems (I haven't even mentioned on-street charging or long distance journeys...) that will become evident when we do. We need to be fixing them today. Claiming they don't exist is naive. Remember that there's just over 1 million electric cars on US roads today, out of 273 million vehicles. The infrastructure needs to grow by 2 orders of magnitude to support that.
That does not sound right. Napkin math: A tiny Renault Zoe has a 52kWh battery. Even assuming 100% charging efficiency, charging for 8 hours over night you’re looking at 52/8=6.5kW per hour. That’s already more than twice as much as an oven, and an extremely conservative approximation.
edit: thanks for pointing out what I missed. I was somehow fixated on full recharges.
A Zoe has a 245 mile range on said battery, but assuming you drive at 25% efficiency for 20 miles to and from work, you'll use about 30% of a zoe's battery in a day, which spread out over our 11 hours from earlier gives about 1.5Kw per hour.
- My EV has ~30kWh battery
- I charge about twice a week, overnight, from around 50% to 100%, if I drive to work every day
I have a relatively short commute to work. So this is may be a lower bound. But charging 52kWh every single day is definitely an extreme case on the other end.
Where I'm from, EVs typically charge at 10A-32A at 220V, or 7.4kW to 22kW with level 2 chargers. That means you can't charge a Tesla from 0% to 100% over night, but then I haven't heard of anyone who actually needs to do that every day, if ever. The closest I've done personally is charge a Tesla I borrowed from around 30% to 100% at a cabin, but then I started when we arrived in the afternoon and we left just before noon.
It's weird that you'd call a 52kWh Zoe tiny btw. 52kWh is quite respectable. It's only half of the largest EV you could possibly buy now, and I'm guessing 50-70kWh will be the standard mid/entry level battery size for a long time.
30-40kWh cars might disappear. That'd kind of be a shame, because it's a useful size for many people. And having a larger battery than you need is a huge waste unless you have vehicle-to-grid to get more value out of the battery capacity you're not using. But then again, maybe the 30-40kWh market will be taken over by second hand 50-60kWh cars with reduced capacity.
I am sad that there are so few good subcompact/ truly low energy options in this market. There is a tiny Chinese car coming to the US, but right now it seems like it's only going to hit a few markets.
The American (genital) size contest for SUVs and Trucks has sucked a lot of oxygen out of what is a much more interesting variety in EV production for Asia and the EU.
Average drives do more like 12,000 a year, not 80k miles.