Articles
Steam has been used to generate power since the early days of electricity, but it’s not the same as the steam that comes out of your kettle. That’s wet steam, and what you see there is actually moisture – water droplets – coming out of the top.
You can’t use wet steam to generate power, because it will erode the turbine blades, so in industry you have to generate superheated dry steam to drive turbines. That’s more complicated and expensive, and the vast majority of industrial processes that use steam – making chocolate or chemicals and brewing beer – don’t need superheated steam.
Companies generate steam at one pressure and use it at a lower pressure, so they let that pressure down through a valve, but because they can’t use wet steam the potential electricity-generating benefits have been wasted, until now.
Around 2009, City, University of London developed a piece of equipment that could harness that power. City has more than 40 years of experience in air compressors, but its researchers started working with a client on a project to expand steam from a geothermal scheme. They saw that it was a great opportunity to develop equipment that would expand wet steam rather than dry steam, and turn a shaft.
Having got to that stage the obvious thing to do is to use it to generate electricity, which is what we’ve done. Our machine replaces or sits alongside the valve that lets down the pressure of the steam. It works exactly like a compressor but the other way around. We’ve got two rotors and as they turn they open up a gap which the high-pressure steam at the inlet side can go into. As the pressure reduces, the steam expands through the rotors and as they turn the chamber gets larger. The clever bit is in the design of the rotors, and how the expanding steam naturally turns the rotor.
Heliex Power was spun out from City in 2010 by a professor, Dan Wright. The first few years were spent turning a bench-top, university-scale piece of equipment into something of an industrial nature so that we could sensibly take it out to a blue-chip industrial customer and say, ‘Would you like to buy one of these?’.
We’ve got three very supportive shareholders – BP Ventures, the Irish Electricity Supply Board and Scottish Enterprise – who recognise that you don’t turn this sort of technology into an overnight success. It takes time and effort.
You start off doing a lot of engineering to develop the package, and then a lot of test work to make sure that it operates as predicted. That took the best part of three years. I joined about 18 months ago to run the company. I’m a chemical engineer by training and I’ve been in the equipment supply industry all of my career, but I’d worked my way to the point where I was away from the coalface. So I was looking for something where I was back closer to the actual business itself, talking to customers about the technology.
We measure our success by operating hours. We now have in excess of 130,000 operating hours, and we’ve sold a total of just over 50 machines at a price point of anything in excess of £100,000.
Over the last year or so we’ve been developing a steam re-compressor, and a way to use our expander to drive an air compressor as well. But our short-term growth will be in going to new industry sectors and new geographic territories.