Does making the battery for a hybrid car take more energy than the car saves?

A Humvee

Some folks on the internet have actually tried to claim that a hybrid car uses more energy than a Hummer. Lol!

I recently heard someone trot out a factoid i’d heard before a couple of times:

The battery on hybrid cars takes so much energy to produce that it’s actually greener to drive a normal car.

As a Prius owner myself I wondered; could this be true?

Toyota have been rather tight-lipped about the exact details of Prius battery manufacture, although this is probably just because they consider their Hybrid Synergy Drive technology commercially sensitive (at least while they’ve got such a lead in the hybrid market over their competitors)

So let’s take a guesstimate at some numbers and see how it stacks up:

A new Prius starts at about £20,845. Let’s be generous to the sceptics and say that making the battery is a whopping 20% of the sticker price of the car (it’s likely much less than this). That means it costs £4169 to make a battery. Again, lets humour the sceptics and say that 90% of the cost of the battery manufacturing process is energy and that Toyota pays the equivalent of 5p/kWh. That puts the energy consumed during manufacture at 270GJ. That amount of energy is equivalent to a little over 1800 gallons of petrol. Toyota rate the hybrid drive as offering an improvment of about 25mpg over a standard drivetrain (using figures from the Auris vs Auris Hybrid), even if that’s only 15mpg in reality then a Prius would only take 27,200 miles to make back the energy used making the battery. Remember, those numbers I chose are extremely pessimistic, it’s likely that the real break-even point was much sooner.

Toyota’s warranty on their hybrid batteries is eight years, so unless you don’t think you’re going to put 27,000 miles on the clock in that time, a hybrid will reduce the amount of energy your driving consumes.

So bottom line: even a rough calculation of the energies involved does not support the claim that building batteries for hybrid cars is more wasteful than driving a conventionally powered car.

If you want to play around with the numbers, you can download this spreadsheet.

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One Response to “Does making the battery for a hybrid car take more energy than the car saves?”

  1. Joe Says:

    I think the when they state the regular car is more green than a hybrid, they look at the energy cost of producing the batteries from mining the lithium up to and including proper disposal. On the other hand, they do not look at the energy cost of drilling the oil wells or producing catalytic converters, etc. when looking at the “regular” cars.

    So it is very likely that when comparing total costs from obtaining the raw materials (natural resources) to final disposal, the hybrid vehicles are more green than regular vehicles. There may be a few, such as those new diesels that get 45 to 50 mpg where that might not be the case.

    Even then, whether one does predominately city driving or highway driving will make a major difference as to the overall “greeness. Suffice it to say, though, a hybrid will never be worse than a fully petroleum powered vehicle and will almost always be better than one when it comes to its total carbon footprint.

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This page last updated 21 October 2012