Wednesday, February 6, 2008

Ultracapacitors -- better than batteries?

We're all familiar with batteries of various rechargeable and disposable varieties. The stored electrochemical potential energy in batteries allow us to start car engines, fire up laptops, take cell phone calls, and jam to music from ipods.

Batteries are clearly versatile devices for storing and delivering mobile power, but they have some drawbacks:

1) Charging can take a long time.

2) Batteries don't last forever, and they lose capacity and performance with use. Rechargeable batteries usually fail before the the devices they power rust, break, or become obsolete. This is inconvenient and not ideal from a sustainability standpoint (see 3).

3) Producing batteries requires large amounts of energy and toxic materials (which disposal safety hazards).

4) Battery performance in situations requiring large amounts of power or storage is lacking. In applications such as electric vehicles and off-grid RE homes, energy storage is still a critical limiting factor in terms of capacity and expense.

Enter ultracapacitors, technology that could potentially avoid many of batteries' drawbacks. Ultracapacitors charge fully in a matter of seconds or minutes rather than hours, take millions of charge cycles (they would likely outlast the devices that they power), and have higher power output than chemical batteries.

Capacitors are fundamentally very simple, storing energy by accumulating static electrical charges on parallel plates separated by an insulator. Capacitors have been around for a long time, and populate circuit boards of electronic devices for a variety of purposes. University researchers and a few R&D companies are now extending this technology to push the envelope of energy storage capacity, by increasing the surface area of the capacitor's plates, and by using insulators with special properties.

Are you CHARGED UP and ecSTATIC to learn more? Check this out.

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