> -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of xponentrob > Sent: Wednesday, January 07, 2009 7:21 PM > To: Killer Bs (David Brin et al) Discussion > Subject: Re: Scouted: U.S. to collapse in next two years? > > If one wants to make direct comparisons of a type of batteries > capabilities, > one has to go no farther than a hardware store or Lowes or Home Depot. > I've been using cordless drills for a couple of decades. They were once > using Ni-Cad batteries, until the Nimh batteries swallowed the market. The > Ni-Cad and Nimh battery packs were pretty much the same size and performed > about the same, only Nimh had a slight edge in most categories. In the > last 2 years Li-ion batteries have begun to take over the market. > The battery packs are smaller and lighter, but deliver more power > and torque and do it for longer with a shorter recharge time. > In short, Li-ion are starting to dominate the market and it is a market > that has requirements that has similarities to the requirements in Auto > applications.
I agree with your methodology, but wish to add one thing: cost. The added cost for modest energy densities is not a big factor, but at $4.27 per Wh, it means a lot if one needs a lot of watt hours. In the case of power tools, the use isn't as much as one thinks, My memory is that the Tesla uses these batteries, and its price tag has a lot to do with how expensive they are. I think we'd need a factor of 10 reduction in price/Wh before they are commercially feasible for Joe and Joan commuter. But, I would not necessarily rule that out; because the evidence for research on the techniques indicates that there may be some room for improvements both in storage density and price per battery. The other factor is that we will either need to switch to nuclear power for virtually all of our electricity or find a very efficient high volume energy storage system to match with wind. Right now, power grids can count on only 5% or so of the rated capacity of wind farms. Pairing them with natural gas plants makes this reasonable, but then we are burning fossil fuels to get the electricity. That's slightly better for the environment than gasoline, but far worse than high tech biofuels that might come on line in 5-10 years. So, in the short term, I'd argue for building nuclear plants, finding ways to make batteries denser and cheaper, and biofuels from non-food sources which produce aviation fuel far more efficiently than ethanol is produced, developing high efficiency massive energy storage, and a raise in the gas tax. But, you've heard that before. :-) Dan M. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
