Green with ENV

OUR interest in exploiting alternative sources of power waxes and wanes with the price of petrol, but as sure as night follows day we’ll eventually have to find something to replace the magic elixir of youth – fossil fuel.

Not long ago I had the opportunity to take a closer look at a motorcycle powered by one such alternative, a fuel cell that reacts hydrogen and oxygen together to form water, and uses the energy released by the reaction to power an electric motor and so provide forward urge. It’s one of just two two-wheelers in a worldwide population of about 800 fuel-cell-powered vehicles, and currently lives at Loughborough University in the UK, where it was built by Intelligent Energy (IE).

In its present guise the bike, called ENV (Emissions Neutral Vehicle), is a spindly, ungainly looking creature with the seat height of a motocross bike and the power output of a moped – 6kW, enough to give the bike a top speed of about 80km/h.
But none of that matters. What’s important is that it’s been built, and seems a sound prototypical platform on which other, more viable models can be built. IE’s Director of Communications, Jon Moore, told me more about it.

BG: How did the project start?
JM: It was an internally driven and funded Intelligent Energy project. We sat down and asked ourselves if we could do a fuel-cell motorbike. We designed the bike around the fuel cell rather than the easier option of taking a bike and removing the engine, which would have given us scope to make something quite different looking. The looks are important: it’s making a statement. There’s a lot of fibreglass on it, a lot of styling features that won’t survive in the process of taking the thing forward to roadworthiness, but we wanted to make something good looking and desirable to customers, and as the bike has won a number of international design awards, we think we succeeded.

BG: Is the bike an end in itself or a convenient testbed?
JM: It’s both. It shows what can be done with fuel cells; motorbikes have generally got under the radar environmentally, but various studies have shown that they’re actually tremendously polluting.

BG: I understand you have a developmental association with Suzuki.
JM: I believe the ENV was important in initially proving our credentials to Suzuki over fuel-powered two-wheelers.
In 2007 we jointly presented the Suzuki Crosscage concept fuel cell motorbike and we now have a joint development agreement with Suzuki – the Crosscage is very clearly their bike but it’s got our fuel-cell system in it and that’s really what we do across the business: put our fuel-cell systems in our business partner’s applications.

We’re presently a small company, whose business model is to develop the technology, for our partners, and then work with them to minimise the time to market. Generally, the partner will already own a sizeable market share of a particular sector. We work across a wide range of market sectors: transportation (cars, bikes, taxis and aircraft), stationary power; portable power, smaller fuel cells for battery replacement and back-up power as well.

ENV Concept Bike
ENV Concept Bike

BG: The chassis is very striking. How did the design evolve into its present form?

JM: The design is by Seymour Powell, one of the UK’s leading design houses. The bike has won awards from Time magazine and Popular Science.

BG: It looks very light.
JM: It weighs about 90kg – lighter than me.
But that’s partially because it has no proper lights, no indicators and it’s not built to withstand collisions to any extent.
That’s for the next stage.

BG: So how does the drivetrain work?
JM: Air passes through the nose of the fairing and enters the fuel cell, where oxygen in the air is reacted with hydrogen from the bike’s supply. A hydrogen atom consists of one proton and one electron. The atom is ‘split’ so the proton combines with oxygen to form water – the ‘exhaust’ product – while the electron goes into a circuit that powers the electric motor and drives the bike, and is then channelled back to the fuel cell. So ENV is a fuel cell-battery hybrid: both the fuel cell and the battery feed the electric motor which I think is a 48V DC unit. The fuel cell makes about 1kW and that’s sufficient for cruising. The battery pack makes something like 6kW, which is for acceleration. The fuel cell also charges the batteries.

BG: How is the hydrogen stored?
JM: In a carbon composite cylinder. It’s just like a normal gas cylinder but the carbon composite weighs a fraction of stainless steel.

BG: No problems with pressure?
JM: Traditional stainless steel takes about 125 bar ; those we use can take 350 bar, but the latest technology stores hydrogen at 700 bar and higher. The cylinders are much safer than stainless. If they ever fracture or have a problem they don’t splinter and shatter, they just crack and vent.

BG: What’s the bike’s range?
JM: About 160km. That’s about 40km on the batteries and 120km cruising on the fuel cell.

BG: Where do you find your hydrogen?
JM: Loughborough University has built its own refuelling station; there is also one in Birmingham and others will come around UK. Boris Johnson is getting 10 hydrogen buses for London in 2010; there are already some in Wales. Conversion will happen slowly: to connect all the petrol stations in the world to dispense hydrogen overnight that would cost hundreds of billions. You need to introduce the fuel cell vehicles and the appropriate refuelling infrastructure gradually, first with fleet vehicles, then later used by the consumer.

Here, the university refuelling station, which is currently supplied with hydrogen from natural gas, will soon change hydrogen supplied by an electrolyser, which is a reverse fuel cell – it cracks water into hydrogen and oxygen.
The electrolyser itself will be powered by the grid – and the university only buys green electricity, so there’s a case for saying it’s a renewable resource. The aim is to have the electrolyser powered by its own wind turbine, so that way you have a local, truly renewable resource. Hydrogen is going to be an important part of the energy mix for the new millennium.

Renewable energy supply, wind in particular, is very variable and you have a lot of difficulty feeding it into the grid, which like energy has to be supplied in a predictable way. So if instead you made hydrogen with the renewable energy, you could store the hydrogen, put that into fuel cells and then put that energy into the grid. Alternatively you could sell the hydrogen as a transport fuel, so hydrogen could enable a merging of the power generation and transport sectors.

If you take natural gas and turn it into hydrogen and put it in a fuel cell, you’d get a lot more miles than you would by taking the natural gas and burning it in an engine. You also get something like 30 per cent less CO2 emissions. It’s a much cleaner way of using that carbon source. Unfortunately, many people decide they’re either for or against the technology.
Battery people for example often denigrate fuel cells because they see them as a sort of commercial threat, where they’re actually complementary technologies.

There’s going to be a mix of cleaner technologies oil and the internal combustion engine will not be replaced by with just one other technology, we’ll gradually replace it with a range of other things.
There is no one-size-fits-all technology, there is no silver bullet; but there could be said to be a range of ‘silver buckshot’ solutions. Because this is the first fuel-cell bike, carrying the hydrogen posed some new questions. In a fuel-cell car the hydrogen’s somewhere on the floor at the back, where the petrol tank would be in the roof in the case of a bus.

On a bike you’re sitting over the hydrogen tank, so that’s something that needs to be thought about – and all the safety and so on for all the various scenarios of what might happen to the bike in a crash. The bike wouldn’t be any more dangerous than a conventional motorcycle, but presents a different set of hazards to be considered.

BG: It’s a bit early to be talking about maintenance, but what would you need to do to keep the bike going?
JM: Probably the main thing would be the air filter.
There are fewer moving parts than in a conventional engine, and where standard components are used, maintenance would be the same as for any other vehicle.
Fuel cells are generally regarded as having reduced cost implications due to reduced maintenance needs.
Moving parts are generally what cause your problems and the power-generation part of a fuel cell works electro-chemically.

Making ENV hum In a fuel cell such as this, hydrogen gas is fed into one side of the cell while air is channelled to the other.
The hydrogen is ducted to a catalyst (called the anode) that splits the hydrogen atom into its basic component parts – proton and electron.
The protons pass through a membrane towards the cathode, while the electrons pass through an electrical circuit (providing power for the electric motor) and are then drawn to the cathode and join the reaction between the protons and oxygen molecules from the air stream to form water. Each cell is designed with optimised surface area to help the reaction along.

ENV’s fuel cell has 48 of these reaction cells in what’s called a stack. The operating principle is quite simple, and comparable to a lead/acid battery in its use of electron migration from anode to cathode to generate electrical energy. Unlike a lead/acid cell, however, a hydrogen fuel cell can run indefinitely – as long supplies of hydrogen and oxygen (air) are kept up to it.

Other than water, the only by-product of the reaction is heat, though as ENV’s operating temperature is around 40 Centigrade, it’s not a major problem. In its present guise ENV has direct drive from the electric motor to back wheel. Jumping on board and twisting the throttle yields silent and fuss-free forward motion – as you’d expect from a motorcycle powered by an electric motor.

Acceleration is brisk and linear, with the bike snapping forward from a stop quite impressively.
Perhaps strangest of all is its behaviour when stationary. There is silence, and just a wisp of steam from the side-mounted exhaust where the fuel tank would be on a conventional bike. That puff of steam is entertaining, and, but for the Doctor Who-style instrument readout that offers information on battery charge, hydrogen volume remaining and so on, it reminded me briefly of the steam-driven cars that enjoyed momentary popularity around the turn last century.

But disregards the looks, the quality of the ride and all the other issues that form part of the assessment process you’d use on a conventional bike.
This is a prototype.
The point surely is that ENV can propel its rider from A to B – forget how far or how fast – on hydrogen power.
It works.

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