Saturday, June 09, 2007

Wireless Energy Inefficiency

Wireless Energy Lights Bulb from Seven Feet Away: Scientific American

The idea of not having to deal with a power cord for recharging portable devices has appeal, but it's an example of where government regulation has a role.

On the MIT tabletop, this system of energy transfer is only 40 percent efficient, meaning that it takes more than twice the energy to do the job a power cord would do (reasonably assuming that resistive losses in the power cord, though non-zero, are negligible).

Efficiency will improve somewhat (possibly to as much as 70 percent) by the time this sort of product is generally available, but that still represents a large energy premium, especially when you include significant upstream losses. Considering the large number of portable devices out there, that's a lot of coal burned and CO2 emitted. It's an unnecessary load on an already overloaded national energy grid. It's the wrong way to go.

We live in an age when increasing energy efficiency is critical for various reasons. Just as some jurisdictions are beginning to ban incandescent lighting, this sort of wireless powering of portable devices probably ought to be disallowed for non-essential applications.

In some applications this mode of energy transfer may make good sense, but if you believe (as I do) that humanity is rapidly (and increasingly so) trashing the atmosphere to the globe's and humanity's severe detriment, if you're in favor of wind, solar, nuclear and other atmospherically benign, renewable sources of energy, then you ought to be opposed to this development for the consumer electronics market.

1 comment:

jj mollo said...

I have thought about this issue myself. It does worry me, but I think its a small thing. I don't really think it's to bad as long as there are incentives to improve efficiency. The other aspect is that energy from electricity does not need to come from fossil fuels. If we make everything electric very convenient and fun to use, then we have a way to wean ourselves from gasoline and two-stroke engines. Everything is a tradeoff. Economics says that the benefits of a product must be considered as well as the costs. The customer does have to pay for most of the costs, which is good. The externalities generated in terms of pollution and CO2 can be controlled at the point of power generation.