Comment & Analysis
It was impossible to see from PE's vantage point at the back of the room, but perhaps Peter Dearman grimaced somewhat as stock footage of him demonstrating his liquid air engine concept was shown to an audience of automotive and cryogenic industry experts congregated at the Society of Motor Manufacturers and Traders in London. At any rate, his reaction was such that it inspired a colleague at the Dearman Engine Company to say, 'we'll be able to replace that soon!'.
Indeed they may. The Dearman Engine was invented by Dearman, in a classic 'man-in-a-shed inventor manner', by a man in his shed – and he still has PR that paints that picture. Now the hope is that his invention, under the auspices of The Dearman Engine Company, a spin-out of liquid air energy storage firm Highview Power, will be successfully commercialised – or that, to use today's parlance, a “killer app” for the technology has finally been found, in commercial vehicle refrigeration units.
The idea is that Dearman's device, a piston engine powered by the rapid phase change expansion of liquid air or liquid nitrogen, whose exhaust is nothing but cold air, could be employed to replace diesel power transport refrigeration units, cutting emissions of CO2 and particulates. According to a study released this week, replacing just 13,000 refrigerated transport units with a liquid air zero-emission solution could reduce levels of dangerous particulate matter and NOx by the same amount as taking 367,000 modern trucks, or those meeting Euro 6 emissions standards, off the road – more than three times the entire UK truck fleet. There are currently more than 80,000 refrigerated vehicles on the road and this number is growing annually; the majority in urban and residential areas.
Local authorities are under pressure to clean up air quality, and facing punitive penalties if they don't succeed. For example, the UK, according to Dave Cherry, environmental assessment manager at Leeds City Council, is facing a bill of £300 million from Europe because of its emissions levels, which it will struggle to pay in an era of government cuts. Meanwhile the city is forced to manage air quality in six designated “air quality management areas” and hundreds of deaths each year are attributed to pollution, with life expectancy for others who have serious health problems such as cardiovascular disease also lower than it should be because of air quality. Meanwhile climate change demands a greening of the transport fleet, and hybrid buses fitted with a Dearman engine that allows the ICE to be downsized are also possible.
How seriously is this invention and liquid air being taken in the context of global warming? Dearman's original parent, Highview Power, has secured funding from the government to build a 5MW energy storage plant and may move to a 20MW design next. It has also has managed to licence its technology to an industrial giant in GE. Dearman, for its part, seems to be attracting support from luminaries in the automotive industry, including Mira and consultancy Ricardo.
But it's important to recognise what it can't do. “Liquid air is not a silver bullet for all of our transport issues,” says Toby Peters, chief executive, Dearman Engine Company. It is unlikely to ever act as the so-called 'energy vector' for mainstream passenger cars, although “we never say never”, according to new Dearman chief technical officer Nick Owen. The engine may ultimately replace three-wheeler taxi or 'Tuk Tuk' engines in the developing world, as one example, or forklift trucks. It is unlikely to ever serve as prime mover for a people carrier.
For now, Dearman will have its work cut out in grabbing a share of truck refrigeration. But Peter Dearman himself may need a more mainstream image in the coming months.