The Riversimple Urban Car, a hydrogen-powered two-seater capable of speeds up to 50mph and of traveling more than 200 miles without refueling, was unveiled in London this week. While the prototype car is itself a welcome development in sustainable travel, the aim of the company behind it is even more ambitious: to completely eliminate the environmental impact of personal transport.

Hugo Spowers, a disillusioned former motorsport engineer and racing driver, believes the existing car industry is moribund and incapable of real change. He founded Riversimple as an alternative business model driven by five fairly uncompromising principles: design a new kind of car; make its design and development completely open source; don't sell cars, but lease them; distribute manufacturing to small, local factories; and enable broader and more participatory ownership.

Nine years in the making and seen for the first time this week, the car weighs just 772lbs (350kg), does the petrol equivalent of 300mpg and produces greenhouse gas emissions of 30g/km CO2 – less than a third produced by the latest hybrid cars.

Each wheel has its own electric motor and regenerative braking, with energy stored in a bank of ultracapacitors and re-used during acceleration. Consequently, there is no gearbox, driveshaft or heavy power-assisted braking and steering systems. This “mass decompounding” enables the car to run on a hydrogen fuel cell of just 6kW compared, for example, to the 100kW fuel cell in the new Honda FCX Clarity model being trialed.

While the car is interesting, Spowers' approach to its design is even more so. Plans for the vehicle will be “open source” and freely available online to be downloaded, copied and, ideally, improved on. Spowers believes that Wikipedia-like open collaboration will help to speed up development and improve the product.

Intriguingly, the car will never be available for sale, only for lease. The idea behind the Riversimple service concept is that leasing aligns the interests of the manufacturer with those of the consumer and the environment. It then becomes in everyone’s interest to make sure the vehicles have a long life, maximum efficiency and use minimal materials.

Riversimple also believes that the mass manufacture of steel-bodied vehicles is inherently wasteful. The ease of producing a carbon composite-framed car makes it feasible for small factories to produce just 5,000 to 10,000 Riversimple vehicles a year and incorporate considerable local variation.

Riversimple claims that it can ensure every stakeholder in the business will have a fair say and share of the benefits because it is not driven by profit. Noble talk, certainly, but since the company is still looking for another GBP20 million (USD$32.5 million) of investment, there may yet be compromises along the road.