H2-readiness for combined cycle gas turbine (CCGT) power plants

Hydrogen is considered a central pillar of the energy transition and an important driver of decarbonization. The energy carrier, ideally in its green form, has the potential for another revolution in the energy sector. Hydrogen will play an important role in the energy mix, bridging the gap from generation to storage and distribution to seamless supply and driving the necessary sector coupling. So whether as a storage medium for energy, or in electricity and heat supply, or even as a fuel for clean mobility - hydrogen has great potential as an energy carrier. Moreover, in the field of reverse power generation, hydrogen is a "no-regret" application. This means that the use of H2 makes economic, ecological and social sense in many applications, with or without the consequences of climate change. The economic aspect in particular has recently gained in importance due to the rising costs of fossil fuels.

The European Union has committed itself to being climate neutral by 2050 at the latest. The Federal Government envisages this for Germany as early as 2045. For the corresponding implementation, the energy supply must also be reconsidered. A successful energy transition requires a combination of security of supply, affordability and environmental compatibility with innovative and sustainable climate protection. Here, hydrogen can, must and will replace the predominant natural gas in many places. With regard to the above-mentioned time horizon, this also means that power plants built in the near future must be capable of climate-neutral operation, i.e. they must be suitable for hydrogen, for example. If these are fired with H2 or a mixture of H2 and natural gas, new questions will arise, especially with regard to safety precautions and the technical conditions. TÜV NORD uses a specially developed H2-ready evaluation scheme to evaluate the hydrogen suitability of CCGT plants. The starting point is the concept phase of the construction or expansion of a CCGT power plant.

Combined-cycle gas turbine (CCGT) power plants will make an important contribution to the upcoming transformation and to meeting climate targets. In addition to high efficiency and the relatively easy conversion to hydrogen, they have another advantage: energy supplies with a short start-up time, as with combined cycle gas turbines, make it possible to fill supply gaps promptly. This is because the increasing share of renewable energies means more and more power fluctuations due to the non-constant availability of light and wind. In a climate-neutral energy supply, H2-fuelled CCGT power plants can therefore be used for reverse power generation on a larger scale. For this, newly built plants must be H2-ready, which, according to the underlying scheme, means that they can be operated with 100% hydrogen.

With TÜV NORD's evaluation scheme for new and existing combined cycle gas turbine power plants, plants and systems can be evaluated on a project- and customer-specific basis in three H2 readiness levels from the early planning phase. No matter whether on behalf of operators, manufacturers, insurers or OEMs. In the present procedure, the consideration limits can be planned individually, are component-related and provide an independent orientation and evaluation aid for the future safety of the power plant concept. In addition, long-term planning with an average operating time of approx. 35 years protects the plant from unplanned downtimes and premature decommissioning. "H2-ready" in the plant construction of a CCGT power plant makes the operation competitive and future-proof on the way to climate neutrality.

The evaluation scheme can be understood as the basis for the "roadmap" for the construction of a new CCGT power plant or the retrofitting of an existing one. It can be adapted to the actual needs of the customer. The evaluation scheme is divided into four steps, starting with the target definition with a requirements matrix, overarching requirements (e.g. fuel, permit management, planning, materials), technical requirements (e.g. fuel supply system, gas turbine, waste heat boiler, valves and fittings, measurement and control technology) and ending with the final evaluation. The evaluation is based on existing technical rules, norms and standards, where applicable and available.

The results at the end of the process allow the upcoming measures on the way to H₂-readiness to be classified. For the customer, the results provide a number of advantages: The results represent neutral proof of the technical feasibility of the (sub)projects. They pave the way to climate-neutral operation of their plant on the basis of securing the future of the system. Moreover, the results serve as orientation in a dynamic environment of a rapidly and constantly changing energy landscape.