Meet the Welsh champion for hydrogen-powered cars
Britain is lagging behind in the development of fuel cell power but the tiny Riversimple company aims to change that
It starts with a supercar, and if anyone suggests the Riversimple Rasa is anything other than super they’re outright wrong. It might only have a top speed of 60mph and a range of 300 miles, but as we wind our way up to the Elan Valley dams in mid-Wales, close by Riversimple’s headquarters in Llandrindod Wells, it feels every inch a thoroughbred. Hugo Spowers, the MD of Riversimple, does admit, however, that “the production cars are going to be quite a bit different from this”.
The Rasa is most super for its fuel, hydrogen, the most common element in the universe and a fuel which will power the next generation of heavy haulage vans and trucks – as well as private cars, alongside battery-electric fare. It’s stored on board and released into a proton-exchange-membrane fuel cell, where in a process first demonstrated by Sir William Grove in 1842 as the gas voltaic battery, the hydrogen passes over a platinum catalyst and then combines with oxygen from the air to give electrical energy. The only byproducts are heat and water.
And yes, it is more complicated than this and you can stack up some inefficiencies in the process of getting and compressing green hydrogen from renewable electricity but, as we’ve often explained, if you generate renewable electricity with wind turbines and solar panels there are going to be surpluses (and shortages) and that’s where hydrogen comes in – as a buffer where you use it as an energy carrier or a fuel.
Of course, our Government and civil service can’t even bring themselves to talk about alternatives to battery power in road transport on which they seem hell bent, even if the rest of the world is rapidly waking up to just what a multi-fuelled world the future is likely to be.
Spowers grins and quotes H L Mencken on the subject of fuelling the future: “For every complex problem, there’s a solution that is simple, neat and wrong,” he says.
And Riversimple is playing the long game in these matters. Juergen Maier CBE, former CEO of Siemens UK, is joining the board in the New Year. Maier is a well-connected heavyweight industrialist and is working to encourage the UK to invest in and incorporate hydrogen technology in its future energy plans. Good luck with that one, Juergen.
Riversimple unveiled the Rasa in 2016 after some 15 years of work by Spowers on various projects where he honed his ideas for low-carbon fuel-cell transport. He worked on the Morgan LifeCar and the Hyrban prototype city car, which were important in the proof of concept, and the Rasa Alpha was launched as a powertrain demonstrator.
A former racing engineer and driver, Spowers has some interesting ideas on the future for urban transport, which including selling the Rasa as a “sale of service” vehicle where every motoring cost (including fuel and insurance) would be covered for a monthly cost of between £490 and £550, which Spowers claims is about the complete cost of running a bottom-of-the-range Volkswagen Golf.
The new Rasa Beta
Even in this second-generation Beta form, the Rasa is a strange looking thing, sleek and wind-cheating, with a rounded roof and long tail for better aerodynamics. The front bodywork is changed from the Chris Reitz-designed Alpha original, being more aerodynamic and better looking. Behind the beautifully balanced scissor doors, the interior is strictly a two-seater, although Spowers says his team is simulating the feasibility of a four-seater.
Riversimple’s idea is simple (the clue’s in the name), but the engineering and refinement are complex and sophisticated. These little cars (3,673mm long, 1,630mm wide and 1,332mm high) derive their name from the Latin tabula rasa (clean slate) and they’ll be “local cars” and delivery vehicles, with restricted ranges, which would mean they’d have to be filled with liquefied hydrogen locally. This in turn would create enough demand to make it worthwhile setting up a filling station.
Yet at the same time the Rasa has a sophisticated four-wheel drive system, incorporating particularly neat in-wheel electric motors. It’s not traction they’re after, though, it’s electrical regeneration.
“The reason we have four-wheel drive,” says Spowers, “is that we want to brake entirely electrically.”
Free energy
So much so that the phased braking system initially closes the hydraulic pipes to the friction calipers, so for the most part all the car’s braking is done by the motors running in reverse; the energy from that process is stored in a bank of capacitors. Brake hard and you can be pushing about 50kW of electricity into the capacitor stack and when you come to accelerate they provide about 80 per cent of the power requirement, which in turn means the fuel cell can be smaller.
“These [capacitors] are essential to the concept,” says Spowers, “since they maximise overrun regeneration and therefore range. Most electric cars have 10 per cent electrical recovery braking, we’re getting close to 50 per cent.”
It means the fuel cell might only typically need to provide about 20 per cent of the power requirement, which again starts a virtuous cycle of low mass, low space requirement and so on. It also means only the car’s cruising speed is defined by the size of the fuel cell; the acceleration is defined by the capacity of the capacitors.
If this all sounds a bit hokum, when you think about the process it makes more sense and leaves you wondering why our current road cars need to be so big.
Exactly how restricted the vehicles would be is still in the balance, but for the moment the Rasa has a design range of 300 miles between fills and a top speed of 60mph with 0-60mph in 9.5sec, which Spowers says means the construction, drivetrain, brakes, suspension and fuel cell can be sized to suit.
While the weight of the pre-production Beta is 655kg, Spowers says the firm would be able to pare that down considerably for production. He claimed a “well-to-wheels” carbon dioxide figure of 40g/km for the Alpha model, which made it one of the world’s lowest carbon-dioxide cars and certainly on par with a small battery electric car.
The fuel cell is a proprietary 12kW unit from a fork-lift truck maker, which weighs 42kg.
“It’s far too big,” says Spowers. “Our first one was a 19kg, 8kW unit, but this is a fit-and-forget solution, low risk and reliable, but working at just 37 to 41 volts, so we’re probably taking a 10 per cent hit in hydrogen consumption.”
It’s still pretty good, though. In comparison, Spowers reckons the fuel cell-powered Toyota Mirai does about 65 miles per kg of hydrogen, where the Rasa Beta does about 200 miles per kg.
All this Rasa research has given a number of lessons to the Riversimple team, including its replacement.
“This has been proof of concept,” says Spowers, “it’s slippery, low and with a small frontal area, but since we didn’t have a requirement for practicality at first, it isn’t very.”
Next generation cars would have better three-quarter vision, a larger boot area and space for a dog.
“You simply can’t have a local car without space for a dog,” says Spowers, though he admits that it’s unlikely to ever be big enough to accommodate an Irish wolfhound.
On test
Over the last few years, Riversimple has received funds from the Welsh Government and the EU totaling just under £4 million and the building of a 20-strong test fleet has commenced.
Two Rasa models went on test with Pembroke County Council last year and we attended the opening of the Fuel Cell Systems 350 bar filling station in Milford Haven which was installed to fuel their 2kg hydrogen tanks.
Yet it’s been something of a trial for Riversimple to get council workers into the cars, although not for technical reasons. “We’ve had tremendous problems with insurance,” says Fiona Spowers, Riversimple’s communications director. “Innovate UK has tried to help but it’s been difficult to get outsiders behind the wheel since Covid.”
So, for the first block of the test, Riversimple staff tracked the journeys of staff and simply drove the same routes, though since last March council staff have been driving the cars.
And the feedback?
“They’ve done several thousand miles now,” Hugo Spowers says, “with about eight regulars and their sense of the car very much depends on what they’ve stepped out of. The van drivers think it is small, motorcyclists think it’s great, the speed merchants aren’t that impressed.”
Spowers says the main benefit of the test has been the way the service team has worked. “We’ve been chuffed,” he says. “They meet every day and discuss the real-time data from the telematics. In three months, there have been seven incidents ranging from a coolant warning to a loss of power. No one has been stranded and in the worst case we had to swap a car. For the most part, though, we’ve been able to solve these things remotely.”
Since the hydrogen filling station Milford Haven is 150 miles and at least two hours away, that’s been something of a boon.
On the road
Surprisingly spacious is the first impression as you climb in. Although the interior materials wouldn’t pass muster in a production car, it all works and is very comfortable, even though you feel quite low and vulnerable.
The drivetrain delivers gentle manoeuvring power, so there’s no fear of collision (but if you did floor it the acceleration from standstill is pretty good). The capacitors deliver enough current to the motors which provide strong torque all the way to the 60mph top speed, which it will maintain pretty much up hill and down dale.
It’s quite stiffly sprung and the narrow 15-inch wheels make their presence felt through the stiff carbon-fibre bodyshell, but once up to speed the unassisted steering feels positive and well weighted, while the ride isn’t at all bad. The handling isn’t the last word at the moment, with a seeming mismatch in the car’s roll stiffness front to rear which manifests as a quick turn-in to corners but a slower response from the back wheels.
Hugo Spowers admits that ultimate handling hasn’t been the main thrust of the research team and there are a number of fixes on the way. And since I’ve driven really good racing cars that were sorted out by Hugo in the past, I’m fully prepared to believe this.
The brakes are quite brilliant, with terrific stopping potential provided by each wheel motor, but also a strong-feeling and progressive brake pedal. Oh, and keen drivers will be pleased to see an old-school manual handbrake.
The Telegraph verdict
With production still a way off, Riversimple is in that difficult area, which is the position of most UK-based fuel-cell and hydrogen companies.
“It scares off investment when the [Westminster] Government says it’s going to do everything with battery electric,” says Fiona Spowers, “so yes, the Government is very much a downer for us.”
In case you were wondering, others do see a future for fuel cell cars such as Rasa and Riversimple has had interest from local authorities mindful that its caring staff might not be able to afford a battery-electric car or have cheap off-street charging facilities and that a fuel cell “local car” could be a low-carbon transport solution.
I have my concerns about the Rasa. I think it needs 70mph capability, the handling needs sorting and the company needs to settle on a design and get on and build it.
There’s also the business of not building their own fuel cells or hydrogen tanks. Riversimple wouldn’t be the first company to base some of its ideas on advanced system integration based on proprietary parts.
“Brabham, Cooper and Lotus never built an engine in their race careers,” says Hugo Spowers, perhaps showing his slip a bit. “And they’re an analogue of what we are trying to do.”
That’s very true, but as the motor industry has found with connectivity based on Apple or Android telephones, outsiders don’t have a say in the continued production of components of the correct size, power and capacity – and replacing such things with bespoke equipment can be expensive. Spowers says he could double the Rasa’s bill of materials without affecting the fundamental economics of the operation, but that’s a big claim.
In the end I hope and want the Rasa to be a success, if only to see such a wonderfully strange little vehicle scurrying around our streets, but there are still some big hurdles for Riversimple to cross before that can happen.