When is green green?
August 8, 2010 11:25 AM

Where can I find out which alternative energy sources are efficient, after taking into account the energy cost of manufacture and disposal?

There are an amazing number of adverts on TV for "green" cars. The cars have batteries made from toxic chemicals that have to be dug up and disposed of. Plus the cars cost a lot of energy to make, just like non-green cars.

What are some good sources for tracking which green product really is green?

I'm specifically looking for something that takes into account energy cost over the lifetime of the product, and compares energy saved with energy used including manufacture and disposal.
posted by devnull to Science & Nature (6 answers total) 1 user marked this as a favorite
Regarding the overall impact of all kinds of products, you are looking to google Life Cycle Analysis, which should incorporate energy, toxics, and all the materials and transportation that goes into the production, packaging, shipment, use, and disposal of the product. It's obviously pretty complicated to get an accurate apples to apples read of one product to another because supply chains are so complicated and there isn't great data or any one database for all the products in the universe. But that's your google term. Try it out for the particular products you're thinking of.

The Good Guide is pretty solid for personal care products: http://www.goodguide.com/ and has a nifty iphone ap that allows you to take pictures of the bar code and it pops the data right out on your screen. It deals with environmental, social and health impacts of the products.

Speaking about cars specifically the Union of Concerned Scientists puts out an annual review of Hybrid cars based on their environmental specs: http://www.hybridcenter.org/
The main issues to watch for with hybrids are that the additional energy from the hybrid technology should go towards fuel savings not performance.

Generally speaking the toxic battery in an electric car is overall less bad than a gas powered engine life cycle wise. That's because the car will be emitting greenhouse gases and other pollutants for its whole life and that one or two batteries only have to be disposed of once. Plus, Global Warming is THE environmental issue of our time and you kinda have to pick your poison. The toxics in the battery don't contribute to global warming. As the market gets bigger for electric cars, safe recycling and disposal will become more readily available.

If you let me know what types of products in particular you're interested in LCA wise, I'll see what I can dig up. (I do this stuff for a living)
posted by paddingtonb at 12:56 PM on August 8, 2010


The batteries for electric cars are going to be far far too valuable to just dispose of at the end of their useful life - they'll be reclaimed and recycled. As for how resource/energy intensive various vehicles are, a crude and inaccurate apples-to-oranges but rule-of-thumb benchmark may be the dollar cost to manufacture it and recycle it afterwards (ie not including subsidies, retail mark-ups, and other distortions)

GM plans to offer a lease option on the batteries for the Volt. I would think that this scheme is probably the best insight to the full life cost of the batteries - since GM retains ownership of the battery under this scheme, all the costs, from manufacture to maintenance to reclaiming and recycling, will all be bourne by GM. So assuming that GM will not want to lose money on the lease scheme, but will also want to keep the Volt price highly competitive, I'd think the lease numbers would give a very good indicator of the total lifetime battery cost. Then you can compare to gasoline.

The cost of gasoline will be higher in greenhouse gases, while the battery costs will be higher in resource and manufacturing.

For a rough comparison, filling the tank of an electric car currently costs about one tenth of the cost of getting the same miles out of a gasoline car, but as the price of gas will go up faster than the price electricity, this will change.

I'd also question your assumption that the batteries are made from toxic chemicals. Back in the dark ages, you would see lead-acid or NiCd electric cars, but the new breeds all seem to be using NiMH or lithium chemistry for the batteries.
posted by -harlequin- at 9:22 PM on August 8, 2010


The cars have batteries made from toxic chemicals that have to be dug up and disposed of.

I wouldn't get too worked up about this. There's nothing particularly nasty about most common battery technologies. Certainly the current nickel and lithium based technologies are less problematic than the lead still used in the vast majority of car batteries, or the cadminum in NiCd batteries.

And as for disposal - these metals are expensive, and are commonly recycled rather than dumped.
posted by HiroProtagonist at 9:59 PM on August 8, 2010


For manufacture costs, presumably less to build is better. So hybrids (compared to gasoline cars) have a disadvantage in construction complexity that they must make up for in gas savings, while gasoline cars (compared to electric cars) probably have the disadvantage in complexity (and being gasoline, cannot possibly make up for it), because gasoline engines are vastly more complex and more massive than an electric motor of equivalent power, and the gasoline motor also requires massive and complex (and expensive) additional systems like the clutch, the transmission, etc. An electric motor+drivetrain is mechanically much simpler and lighter.

Right now, the higher dollar price of the gasoline motor+drivetrain is more than offset by the high cost of batteries, but that might not last.

Sitting between electric cars and gasoline cars in mechanical complexity, the Volt has a combustion engine, but it is a generator to recharge batteries, not a drivetrain engine, so it is smaller and simpler and more efficient than a drivetrain motor, because it doesn't have to be capable of brief periods of high power output, and doesn't need to be designed to sacrifice its energy-efficiency in order to handle ever-changing revs and loads.
posted by -harlequin- at 9:44 AM on August 9, 2010


Thanks for the excellent replies.

Can I ask a question about the answers which have mentioned cost? Does cost here include subsidies?
posted by devnull at 4:16 AM on August 11, 2010


Cost should not include subsidies; the idea of using cost is to get a (very) rough comparison of the amount of labour and materials and energy involved in the life cycle (because it's the only comprehensive metric we have much chance of seeing), and subsidies aren't materials, labor, or energy.
Though to a fair extent, the mass infrastructure of today's society creates hidden subsidies for gasoline cars (the US Defence budget for a black-humor example :-)
posted by -harlequin- at 1:09 AM on August 12, 2010


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