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Comment by rubbingalcohol | Hacker News Reader

Serious question: unless all the electricity for these vehicles comes from completely renewable and environmentally friendly sources, won't banning fossil fuel emissions from motor vehicles just externalize this pollution onto electric power plants? Is there data to show that the environmental impact will be somehow lessened?

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Yes it externalizes it. But it centralises it too, making it easier to keep it clean. It also removes the pollution from town centres making them much pleasanter places to be. The total efficiency of burning oil in a large power station to power electric cars is generally is slightly better than burning the oil (which must be much more highly refined) in an internal combustion engine even if it is a hybrid.

There's also that you have to burn fuel in the tank trucks to get the fuel to the consumer.

Centralized generation is vaguely like dependency injection, or loosely coupled modularity in general, you can put what you want into it.

My only concern with electric vehicles is battery end of life. What do I the consumer do? Will I be able to sell my 25 year old EV? Have we gotten far enough to see what that end looks like?

You use/lose some of the energy in transport, either way. I forget exactly, but high voltage power lines lose something like 1% of their energy every...100 miles?

Another way to look at it would be: How much electricity would it take an electric truck to deliver that gasoline?

By that argument, you lose energy when gasoline evaporates during transportation. In both cases (electricity and gasoline) loss is marginal and can be mitigated by striking a balance between centralization and transport/power line distance.

I wouldn't call it marginal (it's about 7% for the eletrical grid). See https://www.nema.org/Products/Documents/TDEnergyEff.pdf

Merely refining oil into gasoline already has an efficiency of less than 90%.

Marginal doesn't necessarily mean small, but that it's proportional to the overall cost. In economics your fixed costs (eg the cost of building and equipping a factory or an oil field or whatever) go down as a percentage of unit price as you produce more goods, whereas your marginal costs are a function of production (eg transmission losses, taxes, raw materials, labor-per-piece).

> By that argument, you lose energy when gasoline evaporates during transportation.

Please show me where gasoline is being shipped in open vessels for that argument to hold water. Oil tankers? Sealed. Tanker trucks? Sealed. Your car's gas tank? Sealed.

http://www.caranddriver.com/features/high-tech-fuel-tanks

The keyword for the problem you're talking about is the "long tailpipe theory." [1] I was just reading Wait But Why's article [2], which concluded that the overall greenhouse impact will still be lessened by using electric cars over internal combustion.

I didn't dig into the sources enough to conclude that it's truly a better option, but those articles are a good place to start.

[1] https://en.wikipedia.org/wiki/The_long_tailpipe

[2] http://waitbutwhy.com/2015/06/how-tesla-will-change-your-lif...

Do those analyses also account for the energy needed to build the batteries? From the wikipedia link, it looks like they don't.

How big is that fixed cost in proportion to the fuel energy? Also, how much energy does it take to make a combustion engine?

It's not really a fixed cost. Batteries aren't good for forever. They have a limited lifespan.

An electric car could be thought of as a gas car with a very, very large, magical fuel tank. If a battery costs $20k (like a Tesla) and I spend $200/mo on gasoline then that's 100 months (simple interest) or about 8 years, before we even talk about the cost of the car or the cost of the electricity.

I know that this doesn't feel good to talk about, but economics is more about numbers than feelings.

That economic analysis is flawed because you're ignoring the externalities of burning gasoline (health costs, climate change). Only if there were high enough taxes on gasoline to mitigate those effects, then you could accurately do that sort of dollar-cost analysis.

Sure but then every analysis is flawed because everything has some kind of externality that's hard to measure and account for.

How much fuel is burned to make the cells? How much pollution happens to mine the rare earths for the cells and the motors? It's super easy to poke holes in both sides of the argument because building a car is so damn complicated whether it's an ICE or electric.

I didn't downvote you but I really don't think it's hard to measure and account for the externalities in fossil fuels.

1. Calculate the dollar amount per pound of CO2 released that pays for enough tree planting or subsidizes enough renewables to offset the emissions.

2. Apply it as a tax to all fossil fuels and imports from countries without a comparable tax scheme.

Right but that's incredibly naive and uncreative. It presumes that fossil fuels are the ONLY way to do certain things, unless you can spend millions of dollars proving otherwise.

For example, right now most steel is made in electric furnaces which can be powered by coal, nuclear, gas, oil, solar, hydro, etc. What's the right tax for imported steel then?

Let me now make a list of a bunch of other things that are in a similar category: aluminum, most other metals, rubber, plastics, glass, etc.

Machines that are used to process raw materials may themselves be made of raw materials which are sourced in various ways. And those machines may be powered by dirty fossil fuels or clean renewables. Which means that components -- as opposed to raw materials -- are also going to be very difficult to properly classify and tax.

The same for subsystems and full assemblies and entire products.

It's a lot more complicated than "do some math and then apply a tax"

> If a battery costs $20k (like a Tesla)

That's not nearly the asymptotic price, though. Tech is still developing.

Well, let's say you've got millions of classes that all perform the same operation. Now you refactor those millions of classes to rely on a handful of classes to perform those common operations. Now you've just made it easier to eventually refactor those few remaining classes into something nicer, cleaner, more efficient.

Sure, you're just shifting the source of pollution in the interim, but once cars are no longer polluting, changing the source they charge from is the last roadblock to removing those emissions from the system.

Stationary power plants can be optimized much more than a car. A car engine has to give optimal power at a range of torque and horsepower outputs, from starting out at a stop light, to passing people on the freeway, and maybe pulling a loaded trailer. A stationary plant can be optimized to be much more efficient at single rate of torque and horsepower.

Generally, it's much easier to make a larger engine more efficient and pollute less than one that has to be small, light, mobile, and safe in an impact.

Exactly. And we are talking about millions of ICEs in cars vs orders of magnitude fewer "engines" at power plants.

It is easier to monitor and maintain a few large sources of pollution than many many smaller sources.

Plus the large sources of pollution are typically further away from major population centers (i.e. fewer people directly breathing in the output from the smoke stacks), while the small sources of pollution are in the major population centers (i.e. more people directly breathing in the exhaust fumes).

The pollution gets shifted to the power plants, but the greenhouse gas emissions from power plants are often better than those from cars. IIRC, in California the fraction from hydro and other renewables is ~ 25 %. Nuclear is another 15 % or so. Natural gas is a big portion of the rest.

People living in an areas that get all of their electrical power from coal need to be more careful about choosing the better option, though. In those cases, something like a high-efficiency hybrid may currently win.

A huge amount of energy in gasoline is wasted as heat. About 70%. Electric plants lose much less energy due to reusing the heat fairly efficiently. There are some losses due to power transmission there of course. Keep in mind some electricity that ends up in cars would/should come from renewable sources...

http://www.fueleconomy.gov/feg/atv.shtml

FYI the losses of different power plants vary greatly but are higher than I thought. http://www.brighthubengineering.com/power-plants/72369-compa...

All is left for you is to learn why resistive losses on the order of about 30% are necessary for the (unbuffered) electric grid to function at all.

Since charging of electric vehicles can be done intermittently and can also be time shifted, it could match with renewable energy sources relatively well, acting as virtual storage.

Beyond what's been said about efficiency, you have to look forward a bit. Solar is really cheap and getting cheaper. This is anticipating for a future where a much larger fraction of the power on the grid comes from less polluting sources.

Yes, battery electricity is cleaner even if it comes from coal, compared to the energy given by gas in gas-powered cars. I've read an article about this recently but I don't remember which. The point it it's much more "efficient" to create that energy in a power plant than it is to do it within a small car engine.

Now, add to that the fact that in the US, the electricity is not 100% produced by coal and natural gas (I think 70% in total, but that number will also shrink when more companies adopt solar panels and batteries for power generation/storage).

Also, it's much better to keep the pollution away from the cities and people.

- Electric vehicles are more energy efficient.

- Gasoline requires lots of transport. (Shipped across the ocean, trains, refinery, delivered to a gas station, travels with the car until burned.)

- Electric vehicles last longer.

- Electric vehicles can be charged with a personal solar array.

- Less smog which means better health and cleaner cities. Making density more attractive is always green.

- ICE cars have 152,300 automobile fires per year in the US.

- Even creating electricity using bad methods keeps the pollution somewhat concentrated. Does this matter with regards to climate change? Probably not, but I don't know.

> Electric vehicles last longer.

Do they? Because ICE vehicles last decades and they don't have expensive battery packs that need replacing.

I'm willing to bet all of the ICE-related maintenance will cost more than a battery pack replacement.

I drove a $500 dollar car another 100,000 miles and only had to do oil changes for the engine. I'm guessing shocks, struts, etc that I did have to fix would be the same on an electric. This was on a 90s car, I'm assuming the current generation of ICE cars will only last longer if properly taken care of.

A quick googling produced:

The impact of coal-burning power plants and gasoline can be quantified. The EPA estimates that the average passenger vehicle emits 5.1 metric tons of carbon dioxide equivalents per year. Coal-burning power plants, on the other hand, produce more than 4 million metric tons per power plant, per year. The overall carbon dioxide output of coal-fired electric power plants exceeded gasoline by more than 30 percent in 2010.

California doesn't burn coal. It's mostly natural gas and some oil. Natural gas is a very efficient fuel in terms of CO2 output.

California doesn't burn coal in-state, but it still gets around 5%-7% [1] of its energy from coal via imports from five coal plants. [2]

I can't seem to find any more recent data showing how that coal energy use has declined in the last two years, the most current seems to be 2013.

They appear to have projected to be getting 20gwh of energy from coal in 2015. [3]

[1] https://en.wikipedia.org/wiki/Energy_in_California

[2] http://www.washingtonpost.com/news/wonkblog/wp/2013/06/07/ca...

[3] http://www.energy.ca.gov/renewables/tracking_progress/docume...

These numbers need a bit more data and some unit conversion before they can be compared. Tons/powerplant and tons/car are not comparable units. We need something like tons/mile_electric and tons/mile_gasoline.

If only coal is considered, it doesn't look good.

My math may be way off, but:

coal: 1,933,130,000,000 kwh/yr plants: 518 kwh/plant: 373,191,120 tons/plant: 4,000,000 ton/kwh : 0.01 37.4% of electricity in US

nat. gas: .0005675 ton/kwh 30.3% of electricity in US

tesla S: .3kwh/mi

Coal only: .003 ton/mi Gas only: .00017 ton/mi Coal + Gas + Renewables: 0.0012 ton/mi

avg ICE: 12,000 mi/yr 5.1 ton/yr 0.000425 ton / mi

As we move away from coal and towards renewables, it's obvious that electric cars become the winners. In areas with mostly coal power production, though, ICEs are more environmentally friendly.

It's really telling how freaking dirty coal is.

Even if it does, relocating motor vehicle pollution away from major population centres will still have a massive public health impact.

An electric car generates less than 25% of CO2 as an equivalent gasoline car in California [0]. In every US state, an electric car produces less CO2 than an equivalent gas car.

[0] https://youtu.be/mURbzh9t0_0?t=5m40s

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