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UK Company to Introduce Hydrogen Fuel Cell Urban Car; Open Source Approach

Cutaway of the Hyrban. Ultracapacitor bank is beneath the seat. Click to enlarge.

UK-based Riversimple will unveil on Tuesday (16 June) its first production-intent car: a two seater hydrogen fuel cell urban car with composite bodyshell. Riversimple designed the Hyrban (earier post) to achieve 300 mpg (energy equivalent); the company calculates that the fuel cell car will have well-to-wheel CO2 emissions of 31 g/km when fueled with hydrogen produced via steam methane reforming of natural gas.

The Hyrban has a top speed of 50 mph (80 km/h), can accelerate from 0 - 30 mph in 5.5 seconds, and has a range of more than 200 miles (320 km). Riversimple, founded by Hugo Spowers, a former motorsport engineer and racing driver, earlier initiated the hydrogen LIFECar project through its subsidiary OSCar Automotive Ltd. (earlier post).

Network electric powertrain. Click to enlarge.

Riversimple is establishing an open source foundation (The 40 Fires Foundation) to help advance the development of the vehicle.

The Hyrban implements what Riversimple calls a network electric powertrain—the different components of the car’s electrical system allow electricity to pass in multiple directions (eg. from the fuel cell to the motors or to the ultracapacitors, from the motors to and from the ultracapacitors, and so on). The powertrain includes

  • 6 kW fuel cell (developed with Horizon Fuel Cell Technologies of Singapore).
  • 21 kg of ultracapacitors, capable of absorbing more than 30 kW of power from regenerative braking, and of delivering 15 kW for bursts of acceleration of up to ten seconds, enough time to reach maximum cruising speed.
  • Four in-wheel motors

Almost all braking is done by the electric motors. This energy is then stored in the ultracapacitors bank which can provide 80% of the power required for acceleration. This, combined with the lightweighting, enables Riversimple to use a fuel cell with a fifth the power required in a conventional car.

Riversimple worked with Oxford and Cranfield University on the power electronics, motors and control system.

We don’t believe any one technology, whether batteries or fuel cells, can be as amazingly versatile as the internal combustion engine has been. We believe different types of vehicle will fill different niches, and it makes abundant sense to choose different power trains for different environments. Battery power will be more efficient over short distances but batteries are very heavy and we believe hydrogen fuel cell power will be superior over long ranges (150 miles+) and will emerge as the most efficient and flexible choice for inter-urban vehicles.


Open source approach. Riversimple says it is licensing its designs to the independent open source foundation 40 Fires Foundation for two reasons:

  • Human society urgently needs more fuel efficient vehicles, and by sharing its ideas and designs, Riversimple hopes to encourage others to adopt the technology.
  • Riversimple thinks it is a sound business strategy for a small company trying to complete the major OEMs in one of the world’s largest industries.

Commercialization and manufacturing. Riversimple plans to lease its cars, not sell them; fueling will be included in the lease cost. The economies of scale of carbon composites frames are very different from those of steel-bodied vehicles, the company says, and anticipates that its vehicles are likely to be produced in small factories producing 5,000-10,000 vehicles per year, allowing for considerable local variation in the car.



Nick Lyons

"...The company calculates that the fuel cell car will have well-to-wheel CO2 emissions of 31 g/km when fueled with hydrogen produced via steam methane reforming of natural gas..."

And what would the well-to-wheel CO2 emissions be if it ran directly on natural gas? How much simpler would infrastructure build out be? How much cheaper would it be to fuel the car?

Unless carbon is sequestered in the conversion of CH4 to H2 + CO2, this scheme seems nonsensical to me.


The well-to-wheel CO2 emissions if it ran directly on natural gas might in fact be higher. It depends on how much energy can be recovered using the ultra capacitors and the efficiency of the fuel cells with the elctric drive when compared to an Otto cycle engine.

Then of course folks that hate fuel cells just can't be bothered to do the detailed analysis.


"Horizon Fuel Cell Technologies of Singapore..."

After all the good work Ballard did improving the fuel cell, they end up with this. It seems odd that we hurry up and wait. Ballard makes great breakthroughs and now does fork lifts while this is developed with Asian capital.


Looks to me like another little deathtrap that no one is going to want to buy.


Nick wrote; "...The company calculates that the fuel cell car will have well-to-wheel CO2 emissions of 31 g/km when fueled with hydrogen produced via steam methane reforming of natural gas..."

And what would the well-to-wheel CO2 emissions be if it ran directly on natural gas?
The point dear boy is that this would be the worst case scenario. Ideally the hydrogen would come from renewable sources. This is a UK Company after all.

ejj wrote; Looks to me like another little deathtrap that no one is going to want to buy.
You've never been to Europe have you? They think nothing of driving 'little deathtraps' and, surprize surprize, not too many of them die.


At 50 mph you could go 45 mph on the city streets in California, but would not be allowed on the freeways. Almost everyone commutes by freeway, so it is of little use. If we want to reduce the consumption of oil, we have to have vehicles that sell in the millions.


Also that oval structure is going to be very strong indeed.

Nick Lyons


I'm not a fuel cell expert, but I do believe methane fuel cells exist. CH4 also is much denser and easier to store than H2.


From previous post:

"OSCar Automotive, started by Spowers in 2003 and inspired by the Hypercar work of the Rocky Mountain Institute (RMI)"

RMI knows strong and light body design with advanced materials. It should have great safety ratings for a small car.


Solid Oxide Fuel Cells (SOFC) can take methane directly as fuel. CH4 is reformed at high temperature in the stack to CO and H2, both are fuel for the stack with higher efficiency than PEM H2 fuel cells.

Delphi has produced a 5 kw stack that might work in this application. They could store methane at 1/3 the pressure for the same range or use adsorption with activated charcoal for the same range at 1/20th the pressure. (assuming that they use 10,000 psi here)


But will it fly? If it don't fly, then forget it. We were promised flying cars 80 years ago, so where's our damn flying cars?


I don't know about flying, but with enough of these little non polluters taxiing around, we just might reduce imported oil and clean the air, that is good enough for me.


It will be as successfully as Clive Sinclair's C5....which is to say: it's a joke.

Roger Pham

Keeping it low-cost and small is the best way to introduce a new and (still) expensive technology. This is true for both BEV and FCV. With increase production experience and number, we will certainly see rapid drop in prices. This is true of any new technology.

This car is an excellent design concept for urban commuting elsewhere in the world except in North America. The commercial failure of the 2-seat Honda Insight should serve as an example.


This has got to be the silliest project of the year.

There are no shortage of goofball designs. It's sad that British universities are wasting precious resources on vehicles that stand no chance of success in the market.

An electric version would be cheaper - who wants to drive in that for more than a few miles anyway?

fred schumacher

The main benefit comes from the small size, low weight and simplified hub-motor drive train. The fuel cells add cost and complexity. Although hydrogen fuel cells are efficient, the whole hydrogen supply train is highly inefficient because of the unfriendly at ambient temperature nature of hydrogen. A small IC genset would make this concept more workable.


Were low cost H2 to become available (MIT - Dan Nocera) this little buggy would do fine in towns like Bedrock.



It would be great of roadworthy SOFC could be made. I haven't heard of any, yet.

SOFC fuel cells can operate on a range of fuels, including relatively "wet" ethanol (lower proof), which improves well to wheels ROIE by not requiring as much distilling.

However, SOFC operate at something like 600 degrees Celsius or more, which can require more than 20 minutes to warm up without cracking the ceramics, and those ceramics that are not terribly shock resistant for bumpy driving.

I suspect the reason they chose to run on straight H2 is because it eliminates the cost, weight and complexity of preprocessing other fuels with reformers.


You could just reform methane, methanol or ethanol. Franklin makes an SOFC that will run on gasoline, kerosene or diesel.
It you vacuum insulate the SOFC, it takes a long time to cool down. In a 24 hour cycle it does not cool much at all. They have improved sealing methods and Delphi makes a mobile APU.


99.99 percent likelyhood this is mainly a product targeted at london and other like cities as such the main and overriding goal is to undercut the limit of co2 needed to meet the no congestion charge/ free parking target in a car with enough range to fill the gap the g wiz cant fill due to its short range.

Also likely the target price is low enough with the same rebates other such cars get to make it VERY easy to afford... After all a 6 kw fuel cell stack isnt all that spendy these days and a sub 1 kg fuel tank of only 350 bar doesnt cost all that much either.


"They think nothing of driving 'little deathtraps' and, surprize surprize, not too many of them die."

Obviously the reason for the population problem.


I gotta wonder how the millions of americans who own/ride scooters, motorcycles or bicycles would feel about that "little deathtrap" line.


The Open Source idea is interesting. The plans are made available to the public for anyone wanting to make these or other vehicles that use similar designs, free of patent restrictions.

You contribute to the design and you get to use it. It is like a partnership open to the world. This might eliminate many of the "land mine" legal actions to protect patents that never made it to market, but are waiting to pounce on anyone that does.


The debate on technology could go on forever...yes small cars are only suitable for city mobility, and I doubt you'd see any of these cars in the outback in Australia!! But Riversimple know that, read about the 5 key elements of their approach that's where the true revolution is (

One thing that's interesting about all your comments is that with Riversimple's open source approach instead of just commenting on a blog you could actually have your say on a particular design and maybe even come up with something better for the world.

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