Podcast: Disposing of Batteries

"Hey Mr. Green: What's the proper way to dispose of used household batteries?"

Click here to listen to the answer! You can also subscribe to Mr. Green's podcast.

Podcast:Computer recycling

"Hey Mr. Green: How can I recycle my old computer and monitor?"

Click here to listen to the answer!

Mr. Green is busy on his world-wide publicity tour for his new book. In the meantime, here's a Mr. Green classic column from June 2007.

Hey Mr. Green,
I usually get 47 to 50 miles per gallon on my 2005 Prius and pay between $2.50 and $2.75 per gallon for gas. Is it cheaper, or better for the environment, to charge gadgets like my cell phone, iPod, and laptop in my car or in my house? I'm in the car about two hours a day. —Joe in San Francisco

I could be lazy and simply tell you to worry less about your toys' relatively small energy use and more about their toxic guts and batteries--and to make sure you safely recycle them. But this is such an intriguing question I couldn't resist poking around for an answer. Though off-the-grid energy production appeals to Americans' do-it-yourself spirit, it turns out that a gasoline engine is not a very efficient device for such efforts.

Using your Prius to charge your cell phone will cause you to emit about 80 percent more carbon dioxide than plugging in at home. (The cost is slightly higher too.) There is, however, one exception: You can get "free" energy if the car's battery is fully charged and the braking system is generating enough power so that the gasoline engine doesn't have to run the alternator to charge the battery. Though this is generally not the case, it might occasionally occur as you roll down the famously twisty Lombard Street or one of your city's other steep hills.

Mr. Green is busy on his world-wide publicity tour for his new book. In the meantime, here's a Mr. Green classic column from March 2007.

Hey Mr. Green,
Should I turn off my computer at night or put it to "sleep"? —Dave in Bozeman, Montana

Unless you have software or network hookups that require your PC to be on constantly, turn that sucker off. The sleep mode cuts energy use by 70 percent, but using the off switch reduces it even more--and turning off the power strip stanches the flow entirely. (Please don't confuse power saving with screen savers; though the latter may feature a heartwarming picture, they do not save energy.) Since computers in the business sector alone waste more than $1 billion worth of electricity a year, it's surprising that more fuss isn't made about these simple steps.

It's also rumored that turning a computer on and off repeatedly will cause it to die prematurely. This is simply not true. Even if it were, planned obsolescence would likely kill off your machine first. And when your desktop PC is put to sleep--permanently--consider replacing it with a laptop, which uses only about a fifth as much power.