MICRO GAS TURBINE

Gas turbines are prime movers based on the Brayton thermodynamic cycle where the working fluid is compressed, thermal energy is then added, before expansion in a turbine to produce power to drive the compressor and produce useful shaft power. The term micro gas turbine (MGT) refers to units producing shaft power below about 500 kW. Like large gas turbines, MGTs can achieve high power density and efficiency, and have the advantage of better fuel and operational flexibility than other prime movers of similar power rating. They require less maintenance and the noise level is lower and easier to attenuate than in competing technologies. Despite previous research and development and recent increase in interest, MGTs still have a relatively low market share. Full potential has not been achieved due to insufficient investment in research and development, and the absence of suitable innovations in commercialisation measures such as coordination and innovation sharing mechanisms among stakeholders and exploitation of or influencing energy policy and regulatory framework.

The development of the MGTs started in the late 1980s, driven by the automotive industry searching for an alternative to reciprocating diesel and gasoline engines (internal combustion engines, ICE). This was driven by the advantages of MGTs regarding low emissions, fuel flexibility and a potential to compete on cost with ICE. With the use of high- speed generators instead of a mechanical drive, the technology became suitable for hybrid vehicles. However, at that time (1990s) the hybrid electrical drive train was not a sufficiently mature technology and did not raise further interest. Instead, the technology was picked up for the decentralised power generation market where its long life and low maintenance cost could compensate on cost. There has been a recent drive for effective distributed power generation systems with fuel flexibility using biofuels or Hydrogen and coupling to concentrated solar power (CSP). This, in addition to recent developments in automotive hybrid electrical drive trains, requirements for range extenders, and high power density power plants for small aircraft has led to renewed interest in MGTs.  MGTs are generally developed and produced in Europe by SMEs with limited research and development resources available compared to large gas turbine companies. Designs typically rely on off-the-shelf components (e.g. from automotive turbochargers), which are relatively cheap but are not optimised for MGT systems. With the growing demand for more efficient and cost-effective energy systems to meet emission reduction targets, it is timely that research and development is conducted to take MGTs to a level that realises their theoretical potential.

There is sufficient evidence that MGTs have the potential to become a fast-growing industry in multiple applications with significant contributions to the energy efficient low carbon economy and to energy security and resilience of power systems if a concerted multidisciplinary R&D effort, including the training of highly skilled researchers, is accelerated to overcome the technological and commercialisation challenges and skills gap that still hinder their progress. The applicants have been involved in R&D projects on various aspects of MGT systems and have sufficient experience and infrastructure to achieve the stated objectives. Collectively, the applicants have identified the strong need to provide highly skilled training in the MGT field for researchers and engineers that will form the backbone of an industry with potential to provide power and various forms of energy in an efficient, flexible and reliable manner to many applications. The scientific goal is to make large strides in the progress of key features that will enable the MGTs to overcome current limitations, thus forming an important component of the future distributed power generation paradigm and energy mix. There is also a need for a holistic approach to collaborative R&D frameworks, intellectual property management and product supply chain as well as utilisation and influencing related energy policy and regulations to pave the way for future commercialisation and for setting up a Europe-wide industry around this technology to compete with accelerated development of MGTs such as those currently taking place in the USA. Project partners have recently established the European Micro Gas Turbine Forum (EMGTF) to support commercialisation of the MGT technology.