Portable solar kits aren't new, but the performance and design of these off-the-grid power solutions is continually improving. iSolar's 20 and 40W kits are the latest examples to come to our attention... and with even the 40W kit folding down to only 30 x 25 cm, this is getting into seriously portable territory.

The iSolar kits come with a 12V x 8 Ah lithium battery that will power a laptop computer for up to 2 hours. It also comes with a Maximum Power Point Tracking Quick-charging Controller, which tracks variations in the current and voltage produced by the solar panel and ensures a maximum charge rate for the battery. It takes 8-10 hours of full sunlight to charge with the 20W kit and 4-5 with the larger set-up.

Folded out the 20W version is still only 54 by 51cm and the Bike-use Solar Panel Holder, which comes as an optional extra. Manufacturer C&G even suggests you strap the panels to the back of your bike so you can charge your battery as you ride.

The 40W version weighs just over 2 kg, the 20W version weighs just over 1 kg and the size of these kits compare favorably with competitors such as Suntech's Nomad and Camper kits.

The lithium battery has an inverter output as well as a USB port for bus powered devices. Other standard accessories include a cigarette lighter plug, DC to AC inverter and clamps for charging car batteries.

In the United States, the the 40W iSolar sells for USD$359 and the 20W goes for USD$259.

Clean & Green Technology is seeking international distributors for the iSolar.