GTs in a decarbonised world9 May 2019
Faced with a stagnant market for new gas turbines, the recent European Turbine Network conference addressed a vital question – does the GT have any future in a decarbonised world?
The collective consciousness of the European gas turbine industry has reacted strongly to the needs and opportunities presented by publication of the UN’s Intergovernmental Panel on Climate Change Special Report on the impacts of global warming of 1.5°C, and its warnings about the prospects of keeping the global temperature rise at even this level.
Keynote presentations at IGTC 2018 highlighted that turbomachinery technology, and in particular gas turbines, will make a significant contribution to a global low emission pathway thanks to low emission systems, high efficiency and flexible load response to balance intermittent renewable energy such as wind and solar. Hydrogen from steam reforming of natural gas or from the gasification of renewable solid fuels and municipal waste together with carbon capture, utilisation and storage (CCUS) schemes, and in the future also hydrogen being produced from water electrolysis powered by excess renewable electricity, will further reduce the carbon footprint to (near) zero. The combination of the diverse fuel sources mentioned will also provide the required security of supply for future scenarios with large amounts of renewable energy. It was also highlighted that large scale availability of hydrogen will be a key driver in decarbonising heat and energy intensive industries.
Reasons for optimism
The ETN R&D Recommendation Report, published at the conference, analysed at some length the drivers resulting from current and future market conditions and covered the future GT technologies that will need to be developed to meet them.
It noted that tough EU legislation and targets to meet climate change goals, a recovery in oil prices that improves the investment position, and the transformation of the world gas market brought about by the USA’s shale gas boom give concrete reason for optimism. And despite the renewable boom, it is foreseen (by, for example, the International Energy Agency) that conventional gas-fired power generation, currently the largest gas-consuming sector worldwide, will continue to play a strategic role, providing a reliable and cost effective, dispatchable power source to respond to peaks in demand and to cover reductions in the output from intermittent renewable sources.
The report coves the investigation of more efficient thermodynamic cycles including variable geometry GTs and combined cycle power systems to achieve high thermal efficiencies at high part-load operating conditions; it recommends the development of new thermodynamic performance simulation tools and improvements in material technology and thermal barrier coatings to withstand the higher turbine thermal loads resulting from elevated turbine inlet temperatures; and in applications of GTs, the development of an extended fuel spectrum, better emissions control including the integration of post combustion CCS, and advanced high efficiency cycles such as oxy-fuel.
Technical papers presented at IGTC 2018, together with ETN’s R&D Recommendation Report, provided numerous pathways to the development of carbon-neutral turbomachinery solutions required in a global energy mix.
“Current and future investments along the pathways outlined will enable significant contributions to achieve the energy and climate targets during the energy transition phase and beyond. It will ensure dispatchable power needs can be met as efficiently as possible and bring us closer to cost-efficient carbon-neutral energy system solutions” commented Peter Jansohn, chairman of ETN’s Project Board and co-ordinator of the R&D Recommendation Report.
This was backed by presentations from manufacturers, highlighting different gas turbine technology developments that in an energy system approach would enable and accelerate the transition to a carbon neutral energy future. A keynote paper on the technologies needed was presented by Dr Nils Røkke, of the research organisation SINTEF, and chairman of the European Energy Research Alliance (EERA) under the heading ‘Is there room for gas turbines in a decarbonised world?.
His contention – that we need more power and more flexible power in the future in the form that GT cycles can provide in a decarbonised world, but we don’t need the emissions from the conversion process – can be addressed by developing advanced GT cycles that can operate in post, pre or oxyfuel modes. (Figure 1).
His conclusion is that GT’s will be needed but they will need development to be able to cope with other fuels, with oxidisers, and at unusual pressures and temperatures.
In particular he cited hydrogen combustion as an important element in attempting to reach the well–below–2°C target, a role largely underrated today as supply volumes and timing seem to be major obstacles. However, he says, H2 can
be produced sustainably from natural gas at large scale including CCS and be supplemented by hydrogen from renewables, enabling the development of a mature hydrogen economy. But he noted that the extensive R&D needed in the GT area has to be supported, and R&D has its optimal effect when industrial, EU and other R&D funding can work in co-operation.