Twike

I was at the Open University campus this Friday when I spotted something new (well, new to me at least) - one of these. It's marketed under the brand name "Twike" (heaven help us). It's a type of human-electric hybrid vehicle - i.e. it's powered by a battery running an electric motor or by the driver pushing the pedals if he/she is feeling energetic/the vehicle has a flat battery.

It's like a Sinclair C5 made for two. There are a few differences and improvements, though. The Twike has an enclosed cabin. The bodywork's a lot lighter, so it's got a better power-to weight ratio. The C5 was limited to 15 miles per hour (24 km/h), so that users in the UK didn't have to have a driving licence. You need a licence to drive a Twike, which is said to have a top speed of "up to" 53 mph (85 km/h). According to the blurb on the Twike web site, the Twike is ten times more efficient than a normal car. I don't know what they mean by a "normal" car - there's plenty of room for "normal" in between a Hummer and a Smart car. Twikes apparently do about 150 miles (240 km) between charges. No road tax in the UK, no London congestion charge payable - why not buy one today?

Well, there are a few hundred models of car that sell new for less the £14,980 you'd pay for a Twike. Most of them will carry four or five people, not just two and/or a large load of shopping into the bargain, or all your holiday gear, or that modest piece of furniture you wanted to move, etc, etc. A lot of them are quite fuel efficient - around 500 miles (800 km) on a tank of gas isn't out of the question. And, for long journeys, they can all get up to the legal maximum speed of 70 mph (112 km/h).

So the Twike's trying to enter a market already full of cheaper vehicles that can carry more people / stuff further and faster. Paying no road tax is all fine and dandy, but the price of a Twike quoted above is "batteries not included". I f you're planning to use efficientNiCad or Li-ion batteries, as opposed to heavy, slow-to-charge and inefficient lead-acid ones, you'll be paying several thousand pounds. Admittedly the amortized cost could be reasonable - it's claimed that these batteries can last for up to 1,500 cycles if you look after them, in which case your cost per mile could be almost down to 5p, but the cost of a battery is still a big up-front cost for most people.

I guess the target demographic for this vehicle must be fit (people who don't mid pedalling some of the way), affluent and interested in green issues. At the moment, I think a more sensible choice for this group would be a couple of bikes and a small, fuel efficient car for the price of a Twike. Use bikes /Shanks's pony for local journeys, use public transport whenever possible and use the car as sparingly as possible. For a lot of other people, the Twike's simply unaffordable or impractical.

I hope that personal transport will get a lot greener and more efficient, and we'll eventually get over our total dependence on oil, but I think the Twike's destined to fill a very small niche. The fact that it costs a lot for what it can do is the big deal-breaker. I'm guessing that the cost of manufacturing a light but strong plastic/aluminium body is a lot higher than bashing a car body out of steel. Combine this with the problem of starting small without economies of scale and the Twike becomes a green luxury for the enthusiast. Batteries at their current stage of development are another problem and will continue to be unless superseded a new generation of far more efficient batteries /fuel cells that can be mass produced affordably.