Re: Figuring Out How Much a Hybrid, Diesel, or Small Car Will Save Per Year

Very similar to solar cells. I don't know how much energy is required to manufacturer the batteries in a Prius, but I'd wager it's more than what's saved by the batteries themselves.

Solar cells, in their manufacturing process, require more energy to make than they'll ever produce in their lifetimes.

People forget that when it comes to energy there's no such thing as a free lunch.

The difference in price between the hybrid and regular versions of the Camry and Civic seems to be about $2000-$3000 similarly equipped. If one drives mostly in the city, it seems like he or she would just about break even if he sold it after 4 years (because of the higher resale value).

It would be a mistake to assume that the higher cost of the hybrid is just from the cost of the energy to make the hyrid system. There are the costs of the humans to build the car, mine the nickel, etc. However, for an accurate accounting of the energy used by the cars, one does have to take into account the differences in the amount of energy used to make the components of the cars, including the batteries, as well.

Jeff

I wasn't referring to the actual cost in terms of dollars spent to make the batteries.

To use whacko terms, I'd like to see a comparison of the "carbon footprint" of the manufacturing process in making a Prius, and its associated gasoline savings when compared to say a Corolla during its gas-burning lifetime.

I would, except you have to add to the carbon footprint, that cost of disposing of the used vehicle, which may be more expensive with the batteries or less, depending on how the components are recycled. Unfortunately, the reason why I chose the cost of the hybrid system is that Toyota claims that it is making money on the hybrid system, and I know of no energy accounting for the hybrid system. So the financial accounting is the best I have.

For solar cells, according to an article in Scientific American, it costs about $4 per watt to make a solar cell. If a solar cell converts energy 8 hours a day, it will produce about 3 kWH of electricity each year or about 15 cents worth of electricity. So it will take about 25 years to pay back the cost of the cells. So that is a worst case-scenario and assumes the cost of the solar cells is all energy-related costs.

For the energy accounting, don't trust my cost accounting. In its stead, trust the work done by two Penn State engineers:

Thanks for your take. ASSuming your 25 year figure is correct, I think that says enough.

I hadn't even thought of the disposal, so that enters data which makes the Prius "carbon footprint" even larger.

TNSTAAFL.

What, exactly, are you trying to say by putting the letters ASS in caps in the word assumption above?

We have to start with assumptions and go from there. Do you have a better idea?

The twenty-five year figure is for the financial payback of the solar panels, not the return on energy. According to the article from the Penn State engineers, it only takes a few years (few being 1 to 5 years) to payback the energy. And my assumptions were assuming 5 cents per killowatt-hour (which is what you would get; it costs about 10 to 15 cents to buy a kWH with transmission costs) and that the panels would generate 1 W of energy only 8 hours per day. If the panels produce energy during longer periods of the day (which they would in the desert), both the financial payback and the energy payback periods would be much shorter.

So the actual energy payback is around 5 years (read the PDF article, although they say the payback is really around 1 to 2 years for different technologies depending on where the solar panels are).

Or smaller, because the batteries might be totally recycled using relatively little energy, in which case the carbon footprint goes down, because it save carbon on the next prius.

Not only that, but you can't even break even (I think that is the 2nd law of thermodynamics.)

Jeff

Just a quirk. Calm down. It wasn't aimed at you, but at me. Every time I assume something, it often times bites me in the ass. That's all.

If you check a few of my recent posts, I aimed it specifically at me in a gun-related thread.

It comes from an old saying, "When you assume something, you make an "ASS out of U and ME. Put the caps together.

I had a solar hot water system installed at my home in Key West. So far it is costing me a hell of a lot more annually than before to heat the hot water I use. First was the cost of the solar equipment I needed and the requirement to change the gas power hot water heater that was use previously, to electricity so it could back up the solar system since it does not make enough hot water on it own, on average. Good thing I did not need to pay interest on a load to install the system.

It appears it will take twenty years before I start to save any money and I'm,

If one keeps a hybrid for ten years it will not likely be worth much. You can use it for a paper weight. The $5,000 cost to replace the batteries will be greater than its value at that time

What if you are like me and keep a car for 10 - 11 years? Also, don't we save on oil changes, etc? I'm waiting for a Honda Fit Hybrid. I do like the Toyota Matrix but prefer the Fit. The Fit may be getting a bigger engine for 2009.

Ed S.

Mike's right. The car might be worth a few thousand dollars.

But, with the rising cost of fuel ($100 per barrel close today), you might save even more than you thought.

Jeff