Riversimple Urban Car

CAD drawing of the Riversimple Urban Car

The Riversimple Urban Car is an open source hydrogen fuel cell vehicle that is to be built by Hugo Spowers' company, Riversimple. A working demonstrator vehicle was unveiled at the Somerset House in London on 16 June 2009, and production is planned to begin by 2013.^[1]

Design

The Riversimple Urban Car was designed and developed in Great Britain by teams at Cranfield and Oxford Universities. It has been financed by Sebastian Piech^[2], the grandson of Ferdinand Porsche.^[3]

The Urban Car is a two passenger vehicle about the size of a Smart. It weighs 772 pounds (350 kg), and is constructed of a Carbon fiber composite material body.^[4] The car can reach speeds of 50 mph (80 km/h) and travel for 240 miles (390 km) on 2.2 pounds (1.00 kg) of hydrogen before refueling.^[5] It gets the equivalent of 300 mpg in hydrogen,^[3] and its life cycle assessment carbon emissions are less than 30g CO₂/km.^[6]

How it works

The Urban Car is powered by a fuel cell that converts hydrogen into electricity. This power supply functions like a battery, uses no moving parts, and emits only pure water. There are two novel principles involved with this project: decoupling of acceleration from cruising, and mass decompounding.

Decoupling acceleration and cruise demands

Decoupling acceleration and cruise means that the fuel cell will only need to be large enough to supply the power needed for maintaining a constant speed, which is about 20% of the power needed for acceleration. Most of the car's braking is done by electric motors on each wheel. These motors capture the energy of the car in motion, and store it as electricity in a bank of electric double-layer capacitors (ultra-capacitors). This electricity is used to provide 75% of the power used in acceleration. Because of this, the Urban Car can be powered by a 6 kW fuel cell, which is significantly smaller than the Honda FCX Clarity's 100 kW fuel cell. This requires less hydrogen to be stored on board, and results in an overall lighter vehicle.^[6]

Mass decompounding

Mass decompounding involves designing the car as a complete system, as opposed to redesigning a car originally conceived as being powered by an internal combustion engine into a fuel cell vehicle. The combination of a small fuel cell, along with elimination of the unnecessary gearbox, drive shafts, power-assist systems, and related and resulting components, results in very lightweight vehicle.^[6]

Open source design

The open source design for the Riversimple Urban Car will be stored on the 40 Fires wiki site online. The wiki project is called The Hyrban.^[6] Any small manufacturer can lease the design for free, modify it as desired, and build their own version of the vehicle.^[7]

Leasing

Riversimple will lease the cars over 15 years instead of selling them, with fueling included in the leasing cost. This is intended to increase the life of the vehicles, and reduce materials usage.^[4] The cost of the lease is expected to be about £200 (US$330) per month.^[5]

See also

• Hydrogen economy
• Morgan LIFEcar
• List of fuel cell vehicles

External links

• 40 Fires Foundation open source design foundation
• Riversimple corporate website
• YouTube video of Urban Car's debut

References

1. ^ Dugdale, Addy (2009-06-17). "dvice.com". dvice.com. http://dvice.com/archives/2009/06/riversimple-urb.php. Retrieved 2010-02-08. 
2. ^ "''Sebastian Piech''". Linkedin.com. http://www.linkedin.com/pub/sebastian-piech/0/204/510. Retrieved 2010-02-08. 
3. ^ ^{a b} 09 June 2009 (2009-06-09). "Autocar article". Autocar article. http://www.autocar.co.uk/News/NewsArticle/AllCars/240683/. Retrieved 2010-02-08. 
4. ^ ^{a b} "Riversimple website". Riversimple.com. http://www.riversimple.com/Content.aspx?mode=menu&type=7&key=136c7243-2378-407e-96cf-750d15de37a8. Retrieved 2010-02-08. 
5. ^ ^{a b} "engadget.com". engadget.com. http://www.engadget.com/2009/06/16/hydrogen-powered-riversimple-urban-car-unveiled-makes-your-hybr/. Retrieved 2010-02-08. 
6. ^ ^{a b c d} "Hyrban project". 40fires.org. http://www.40fires.org/Wiki.jsp?page=The%20Hyrban. Retrieved 2010-02-08. 
7. ^ "''Scientific American''". Scientificamerican.com. 2009-06-12. http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=an-open-source-hydrogen-car-with-a-2009-06-12&sc=DD_20090612. Retrieved 2010-02-08.