Modeling net zero

Stand on one of the boulders here at the forest’s edge and you’ll have an unbroken view of it: solar panels glinting in the sun, an electrolyzer, a compressor and crisp blue tanks for hydrogen storage next to the gas turbine testing facility. Called the Zero Emissions Hydrogen Turbine Center – or ZEHTC for short – it’s a glimpse of the energy future.

An extension of the Siemens Energy gas turbine test facility in Finspång, the center uses solar power and excess energy from the testing to produce hydrogen. That hydrogen is then used in turn to power the gas turbines tests, creating a closed-loop energy system that, when scaled up for industrial parks or communities, would release zero carbon emissions into the atmosphere.

The ZEHTC is a model of future decarbonized power supplies, says Markus Jöcker, the center’s project manager and Technology Innovation Manager at Siemens Energy. “With this demonstration plant, we show how hydrogen and gas turbines can be combined with renewables to achieve a sustainable energy system.”

For more than 100 years the small, industrial town of Finspång in southeastern Sweden, with its woods, boulders, lakes and seventeenth-century castle, has been at the forefront of developing and manufacturing turbines.
 

Most recently, for example, the company invested in their own 3D printing facility for repairs, serial-manufacturing and development of power generation parts including the development of new burners that allow their gas turbines to operate on hydrogen.
 

Gas turbines, with their short ramp-up times and flexible applications, play a crucial role in the energy transition, says Jöcker. Solar and wind technologies are going to cover a large part of power generation. But because of their volatility, alternative power systems such as gas turbines are still required to balance the grid.
 

While ZEHTC showcases the role of gas turbines in our future energy systems, it goes a step further, too, using a microgrid to manage and optimize the storage of excess electricity from their solar panels and turbine testing in batteries and hydrogen. “Such microgrids will become more and more important where different energy systems need to work together,” says Jöcker.
 

Now here is where things really get interesting. With renewable energy storage available and a hydrogen-based system in place, thanks to the new burners researchers have been developing, the gas turbines stabilizing the grid could run on carbon-free fuels.

Just behind the ZEHTC in the big, blue and white assembly workshop, the turbines are thoroughly tested before they’re delivered to customers. Today a fuel switch test between gas and liquid is being performed. During ten hours of testing, the full functionality of an SGT-750 turbine is verified with thousands of measurement points.

During the tests, a large amount of electricity is fed into the national grid. But until recently, excess power  couldn’t be utilized.
 

This was an important change, when the ZEHTC went fully operational in late 2021 , says Jöcker. The plant can harness some of the excess power to produce its own hydrogen in the electrolyzer and create a looped energy system.
 

This is how it  works: Using electricity from the solar panels and excess power from gas turbine tests to run the electrolyzer, water is separated into oxygen and hydrogen. The hydrogen is then compressed, stored in storage tanks and coupled to the gas turbine test center.
 

Subsequently, the gas turbines run on this locally produced zero-emissions fuel mixed into the conventional fuel. Based on the system dimensions we will operate the turbine on up to 15% hydrogen. A full scale energy system could however operate on higher hydrogen content, as much is allowed in the specific gas turbine and depending on the available amount of hydrogen. 

The whole process is monitored from a control room, showing data for the different components on a large screen. “We’re measuring the outcome of hydrogen production and its electricity consumption,” says Jöcker, “and putting all this together in different models to extrapolate how it could look in larger energy systems.”
 

The plant provides a solution the market is increasingly asking for, says Åsa Lyckström, Sustainability Strategist at Siemens Energy AB. “We see that our customers want to decarbonize their production, and we want to make sure we can lead them step by step into the energy transition”.
 

The pioneering research in hydrogen combustion over the last decade at Finspång has set the foundation for the ZEHTC. The company is today well on its way to reach the target to run gas turbines on 100 percent hydrogen at the latest by 2030. Tests have already proven the ability to gradually increase carbon-free combustion by up to 75 percent, which also includes the upgrading of existing gas turbines. And SGT-600 turbines with a capability of 60 percent hydrogen have already been delivered a customer. 

The ZEHTC project, partially funded by the EU, has several partners, including local and regional Swedish governments and universities in Sweden and Italy that will do the modeling for the project and research technical aspects and optimization of the center.

One of the research projects is concerned with the question of how the model can be scaled up, explains Åsa Lyckström: “We want to learn more about what is needed, so that this kind of sustainable solution can supply a whole community, an industrial area or a city.”
 

And there are also already ideas for an extension of the project. Lyckström points to a free space beside the hydrogen containers: “We’re definitely interested in working with other green fuels like ammonia and methanol, which in some cases can be easier to transport than hydrogen and might make a better business case for some of our customers.”
 

“Our customers are definitely looking into alternatives“, Markus Jöcker says. Having a power infrastructure with gas turbines in place, he explains, it’s only a minor step to transform it to a fossil-free plant by using hydrogen or other green fuels. “As a gas turbine provider, we want to keep all these doors open”. 

30 June 2021
 

Niels Anner is an independent journalist based in Copenhagen, who writes on business, science, technology and society in Northern Europe.

Combined picture credits: Lasse Burel