Hybrid cars and their "earth savings"

Hey all, I’ve not seen any studies, but have read up on some things. In short, my mom asked me what I thought of hybrids. I post my response below - I’d like any known information on the different subjects I espoused upon - do they really save anything when you figure the life of the car times manufacturing costs (in terms of pollution), or is it all just a marketing gimic targeted at certain audiences?

I wonder about the hybrid cars - I've been doing some reading on them lately, too.

The battery life is expected to be 8-10 years.  They also expect that to be the average life of the car. If you keep the car longer, you will likely have to pay ~$5k for a new set of batteries at some point, as their ability to hold a charge will begin to fall off rapidly.

Many places have laws that require the manufacturers to take the batteries back for recycling, but no one has published anything (nor are manufactures apparently willing to talk about) how much of the battery can actually be recycled.

Problem is, that those batteries are full of heavy metals, which can potentially put more poison in the environment than a regular car would, but I don't know - there's no research that I'm currently aware of that covers this.

Certainly, the hybrids are subsidised by the federal gov't to get the prices to their current level, and even so, you will never recoup your cost (over that of a regular car) in gasoline alone.  Looking at overall environmental effects, however...  Well, I don't know - I mean, it would seem to me that a hybrid is more energy intensive to build (more complex drive train, contains a combustion engine *AND* an electric motor, and maybe also a generator)...  Does the "cost" (in CO2, as that's the big selling point) exceed what will be saved over the life of the car?  I dunno.  You still have to do oil changes every so often, so there's still waste material.

My gut tells me that overall, it's probably near a wash, but I could be wrong.

tomii, I haven’t seen any full lifecycle studies that would show the impact on greenhouse gases, toxic waste, etc., but to me that is all beside the point. Yes, I’ll enjoy the better fuel economy on our new Prius, but more importantly the increased sales numbers for hybrids is the kind of message that car manufacturers listen to. Historically, nothing has spurred innovation and improved MPG like consumer demand, and even if this current generation of hybrids is only break-even overall (for the sake of argument), the next generation will now get built because people are buying this generation. Make sense?

By way of example, Toyota announced this week that all of their cars will be made available as hybrids, they are working on a plug-in hybrid that will use much less gas, and they are considering bringing flex-fuel (such as E85 and biodiesel) vehicles to the American market.

Welcome to the SDMB, tomii.

The Comments on Cecil’s Columns forum is for discussing previously published Straight Dope columns. I don’t know of any column about hybrid cars, so I’ll move this thread. Your question may eventually turn into a debate, but I have the feeling you’d rather have facts than an argument. So I’ll throw this thread over to the General Questions forum.

moderator CCC

Two points:

(1) From a conventional emissions (SOx, NOx, etc) standpoint, regular non-hybrid cars have become incredibly clean. You can buy a SULEV (Super Ultra Low Emissions Vehicle) from various mfgs that has only the most minute emissions. http://en.wikipedia.org/wiki/Super_Ultra_Low_Emission_Vehicle IOW “cleanness” alone isn’t a compelling reason to buy a hybrid car. Most automotive emissions comes from the oldest, dirtiest 10% of the vehicle fleet. Just getting a new car (of almost any type, ULEV or SULEV is better) makes the biggest improvement.

(2) From a gas mileage and life cycle cost standpoint, hybrids must compete with newer, cleaner diesels. E.g, compare the Toyota Prius to the VW Jetta TDI diesel. The Prius is EPA rated at 51 mpg highway vs the Jetta TDI at 41 mpg highway. The Prius is significantly more efficient in city driving due to regenerative braking – brake application helps recharge the batteries.

IMO there’s no clear winner, but both have pros and cons. In the city any hybrid with regenerative braking will have a significant efficiency advantage. If most of your driving is highway, you lose that so newer efficient diesels can almost match that efficiency, plus have more power and there’s no maintenance issue with batteries.

Hybrids are still about 90% marketing and 10% practical. Their best use is as a niche product in areas that have bumper to bumper traffic in an area where the weather execerbates pollution (i.e. Los Angeles). Otherwise, what’s the point really? The energy to charge the batteries has to come from somewhere.

Yes, it is more efficient and less polluting to burn at the power plant rather than under the hood. But you also lose a lot across the power lines. Unless its a nuclear plant its still emitting tons of greenhouse gases. If it is nuclear there are still long term issues with that.

And as others have said batteries have a shorter life span and are much more toxic than anything in an old internal combustion engine.

Hybrids will never be ready for prime time until fuel cells or hydrogen power is practical. Until then they’re still essentially golf carts.

This is a problem for hybrids. Basically, the car dies when the battery does, because almost no one is going to pay thousands of dollars to replace the battery. (I’ve heard figures of $2000 per battery, but even then that’s the equivalent of having major engine or transmission repairs.) This means that a five-year-old hybrid will have almost no resale value. This is why electric cars never took off. General Motors only let people lease the EV1 because they realized that replacing the batteries would be beyond most people’s means, and that the car would end up being a public relations nightmare. Hybrids potentially face the same problem.

Except that the Prius battery is warranteed for 8 years (10 in California)
And the cost of the batteries is going down.
And its unlikely the entire pack will need replacing (there are like 28 6 cell units)


This is misleading. Hybrid vehicles aren’t charged at the plug, but recharge their batteries using braking energy from the engine that would otherwise be wasted. Your complaint refers to electric vehicles, not hybrids.

I completely agree with you, JohnM. I just watched the interview on C-Span with Jim Press (Toyota North America), and he couldn’t stop talking about their plans for environmentally friendly vehicles. The huge sales of the Prius have changed the company’s strategy. No doubt, he overstated things for publicity, but they have charted a course in the right direction which others will follow.

While (most?) do have regenerative braking, the main source of recharging the batteries is running the IC engine as a generator.

Also I feel that this is really the first generation of hybrids (yes I know that some claim to be on their 2nd or 3rd - but it’s still in it’s infancy). I expect to see different hybrid options, plug in hybrids is one such example.

Another one I expect to see is a pnumatic hybrid, in which compressed air is the storage medium. Air motors can be very tiny and lightweight, and are great for raw power, coupled to a IC engine which excels at a base level of power.

Like said above, right now we are looking at 10% practical, 90% marketing, but as the next generation comes along I expect that ratio to start shifting.

  1. In case anybody is still confused, this is not in fact how hybrids work. They get all of their energy from burning gasoline; they just are able to use a much smaller gasoline engine than traditional gasoline cars, because the hybrids use an electric battery to store power from the gasoline engine and feed it back for acceleration.

  2. Their overall environmental impact really depends on how you weigh different kinds of impacts. For instance, is the greenhouse gas savings from improved gas milage worth the extra metals in the waste stream from the batteries? There’s no single, objective way to decide which is worse.
    However, I would argue that batteries to dispose of are not nearly as big a problem as carbon dioxide emissions. It’s possible to deal with the batteries without real harm if they’re recycled correctly, disposed of in a proper landfill, etc. But greenhouse gas emissions always have a real and worldwide impact.

Sure, it would be better if someone invented batteries that degraded to sand and water, but IMO even metal batteries are worth the climate change savings.

It bears saying that all hybrid cars do is stretch out the supply of oil by using less, making it (potentially) last longer. The simple fact is that all the oil on the planet will be burned by someone sooner or later, thus the total pollution will ultimately be the same. So as far as “Earth savings” go, it’s more of a symbolic gesture than a real one. It has the added benefit of burning less and saving the owner a lot of money in fuel, but as of right now that benefit is largely counteracted by the premium over ordinary cars, plus, as you mentioned, there is battery disposal to think about.

What’s there to think about? It’s not like pulling a couple of D cells out of your flashlight and flipping them into the trash; all hybrid batteries are going to be removed at a garage that specializes in them and will take them to an Authorized Disposal Center for recycling. Scrap dealers have been able to handle batteries for years.

What’s your reason for concluding that people will abandon the use of plastic?

Yeah, that’s what they said about trees a century ago.

Sounds really interesting, but I suspect noise may be a problem.

Ford made a concept hybrid SUV a few years back that almost used that. It was hydraulic. Energy was stored in a hydrualic accumultor, which has a bladder full of high pressure nitrogen that is displaced by the hydrualic fluid.
Operating at 2000+ psi hydruaulic pumps and motors are very compact for the power ratings they achieve.

Compressing air is a very lossy process. though.

And they would have been right, too, were it not for the emergence of oil. Wood will eventually re-emerge, being the next-cheapest source of fuel. Or perhaps coal, but when that runs out it’s back to trees.

Don’t kid yourself, dude. This planet will be barren when we’re finished with it. If we don’t strip it clean the sun will consume it when it reaches its next stage.

Thanks, mod!

Plug ins, in my mind, are an abolute no-go. The inefficiencies in power generation are huge. I imagine that it might be nicer in the fact that maybe it’s easier to place pollution controls on a power plant, but even so you’re looking at an end-to-end efficiency on the order of 30%.

Now, if we replaced all of our coal plants with nulcear plants, and opened up a couple of new breeder reactors… Well, I’m all for that, but that’s a different thread, too.