The Dearman Auxiliary Power Unit (APU) offers the burgeoning electric bus market a way to increase its range and offer operators a combination of efficient clean cooling, power and a cost-effective enhancement to a vehicle’s systems, utilising the unique properties of the revolutionary liquid nitrogen powered Dearman Engine.

With low emission electric bus (e-bus) sales estimated to grow globally by up-to four times and China leading this growth – where targets are to convert 50% of its fleet to e-bus – low emission buses have become part of the main OEMs development strategy and with Dearman technology working alongside offering efficiency improvements there is a potential for real technology enhancements and environmental benefits.

Within the Asia Pacific, Europe and Americas the promise of zero emission public transport is high on many government’s agendas. The battle to fight climate change and protect citizens in urban areas from local harmful pollution – the e-bus promises:

  1. Low emissions
  2. Freedom from Diesel
  3. Savings on maintenance costs
  4. Quieter operation

In hotter climates – such as Asia – around 40% of e-bus power is typically required for air conditioning (A/C), reducing the vehicle range proportionally, and this is where Dearman’s technology may be used to eliminate the electrical power required for A/C and extend the vehicle range. Alternatively, a smaller battery pack may be selected to reduce capital costs and charging times, while maintaining acceptable range.

Commenting, Dr Daniel Fennel, Head of New Applications Engineering, said:
“With electric buses replacing conventional diesel-fuelled buses especially in China there is a real need to maximise efficiency and improve their potential range, and in hotter climates provide efficient clean air conditioning and the Dearman APU is an exciting solution to the limitations of the e-bus.”

Having demonstrated the technical and economic benefits of the Dearman APU the next step is a prototype deployment, to further develop and enhance the benefits of a Dearman enabled e-bus.

Dearman’s New Applications team are currently working to develop and demonstrate a Dearman powered air conditioning system that is applicable to e-buses, forming part of a wider project funded by the UK’s Advanced Propulsion Centre (APC5) to support the industrialisation of Dearman technology.

Dearman is pioneering the development of clean liquid air technology

Established in late 2011, Dearman is developing a suite of zero-emission technologies, powered by the expansion of liquid air or nitrogen.

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Peter Dearman inventor of the Dearman Engine