Charging a Laptop By Sunlight?

A reader asks the Green Guide:

Can you recharge a laptop in a more environmentally friendly way, e.g. using solar energy instead of electricity? Seems strange that anyone can power up a garden light, but can't recharge a laptop battery or even get a solar-powered laptop. To date, attempts to either get a solar-powered charger or laptop in the U.K. have proved unsuccessful.

Andrew D.
U.K.

The Green Guide responds:

At present, solar-powered laptops are "nice ideas" that haven't yet left the minds and workshops of forward-thinking engineers. If you want a laptop—today—that can operate off the grid, your best alternative is a solar charger. The most energy-efficient laptops can be charged with as little as 13 watts, and we've found compact solar chargers that can accommodate as much as 26 watts, enough to charge non Energy Star-rated Macintosh and PC portables.

Voltaic System's Generator messenger-style laptop bag holds 17 watts after it's been in direct sunlight for the day ($599; www.voltaicsystems.com, shipping to the U.K is available). At 4.5 pounds without your computer, it's fairly lightweight, and the fabric is made from recycled PET bottles.

In the U.K., Sunshine Solar's briefcase-sized charger can hold 13 watts—but in a heavy nine pounds (£79.95; www.sunshinesolar.co.uk). The 22-watt Solar Laptop Charger at SolarKitsDirect.co.uk weighs half that (5 pounds), but it's more expensive (£415.19).

Sierra Solar Systems (www.sierrasolar.com) makes three different solar chargers equipped with 10-foot cords that allow you to sit in the shade with your computer while the solar panels are in the sun. The compact Brunton Solaris 26 has foldable panels that can be opened in the sun and folded back up to 8.5 by 11 inches. At 28 ounces, it's easy to carry around with you ($390). The Notepower laptop carriers open into solar panels and come in 15- and 22-watt versions and weigh 3 and 6 pounds, respectively ($262-$386).

The Sunlinq Portable Solar Panel Charger from Earthtech Products is another foldable, portable option. It generates 25 watts and can charge gadgets from cell phones to laptops. ($409.99; www.earthtechproducts.com). The Sunlinq charger is sold in the U.K. at www.thesolarcentre.co.uk.