Turbo Expo 2023: The Role of Gas Turbines in Meeting Net-Zero Goals

On Tuesday, June 27 at Turbo Expo 2023, four panelists addressed Gas Turbines for a Sustainable Future. Executives from Pratt & Whitney, GE Aerospace, and Rolls-Royce discussed the challenges and opportunities of sustainable aviation while Dr. Kathleen O'Brien, Vice President, Technology & Innovation at Siemens Energy, addressed the power-generation sector and how Siemens Energy is addressing net-zero goals and some of the challenges and technologies available.

“As an electrical engineer, I can relate to the fact that demand growth and decarbonization can seem to contradict,” she said. “Through both electrification and starting to use hydrogen in some of our gas turbines, we can power clean loads with clean energy.”

Siemens Energy views a clean-energy future through the lens of four different focus areas (decarbonization, demand growth, decentralization, and digitalization), and using what the company calls “the five fields of action,” it develops technology to address these focus areas.

• Power-to-X (e.g., hydrogen-powered gas turbines)
• Energy storage
• Decarbonized heat and industrial processes (e.g., electrical heat pumps and heat waste recovery)
• Condition-based service interventions
• Resilient grids and reliability

In relation to net-zero goals, Siemens Energy has “technology that allows more renewables to get on the power grid, which allows us to integrate more renewables quicker and allows us to then take advantage of regional ecosystems with hydrogen and other technologies to do things at a much faster pace,” O'Brien said.

Other technologies being developed include electrolyzers and fuel cells that can help the industry more efficiently and more cleanly run heavy-duty vehicles or trucks as well as technologies that address hydrogen from a cost perspective.

Gas Turbines

O’Brien said that it is a lot easier to do a hydrogen-based gas turbine on land, relative to challenges faced by aircraft applications. Currently, the company’s gas turbines co-fire between 15% and 75% hydrogen by volume, depending on the turbine frame. There is a lot of interest in hydrogen co-firing on gas turbines even though the infrastructure and the business case are not there today. The company also has a technology path to operate its gas turbines at 100% hydrogen by 2030.

She highlighted a recent collaboration between Siemens Energy and Constellation that offered real-world insights into hydrogen blending with natural gas. In the demonstration, they reached 38% by volume hydrogen blend in Siemens’ SGT6-6000G turbine, allowing them to produce over 36 MW on the gas turbine and 54 MW on combined cycle from the energy content of the hydrogen. It stayed within the required NOx emissions levels without steam or water injection.

“What this means is 16% of the total MW generated were generated by hydrogen,” O’Brien said. “This reduced the carbon emissions by 16%, but without any increases in NOx.”