Micro stock Voller Energy, having originally tried to crack a few years ago the portable power pack for laptops, ipods and mobile phones and clearly not having succeeded, is now trying to break into the construction market.

I have to say this looks like their most promising venture yet. You buy an ipod because it's small and neat. The Voller fuel cell charger is not that - they really don't fit together and the noise it makes would make it hard to work on a laptop.

But it's chunky yellow looks (see here and click on movies at bottom left of page), somewhat reminiscent of a JCB digger are a plus for the unfussy, no-nonsense builder. The sales channel is promising too - Speedy Hire, the leading supplier of cordless tools to the UK construction industry. The aim is to for the fuel cell generator to replace diesel generators in the 200,000 static shelters for construction workers in the UK.

I'm also wondering if there would be scope for scaling up their technology. The highly portable gas 10 inch canister that is used with the unit is pretty small. Why not connect it to a 13 kg gas cannister (as used in a large barbecue) and run much bigger machinery, like road-digging tools, a bit like they do with their marine products?

For serious power applications, the 100 watt limit of the fuel cell generator could then be lifted to 2 kilowatts.