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Just what goes into converting a gas-fired turbine to hydrogen?: the MHPS perspective on carbon-free thermal power

Many power generation companies are doing interesting and exciting work toward a future of lower carbon emissions in the energy sector.

A large number of these are on the renewable energy front, but others see a sizable role of low or no-carbon thermal power in the form of nuclear and hydrogen.

Those companies tackling the hydrogen generation equation include Mitsubishi Hitachi Power Systems (MHPS), Siemens, GE, Ansaldo Energia and more. MHPS announced this week that it was contracted to deliver gas turbines to a Utah power plant that will eventually utilize hydrogen on a large scale.

The Intermountain Power Agency deal with MHPS calls for M501JAC gas turbines that will include a 30-percent mix of hydrogen by 2025. MHPS will be taking that to 100 percent renewable hydrogen by 2045.

“We’ve guaranteed 30 percent operation on hydrogen as part of our contractual commitment,” said Mike Ducker, vice president of renewable fuels at MHPS Americas. “The customer has stated that by 2045 we must operate with 100 percent renewable hydrogen” and he predicted that “we’ll be taking steps in design and testing of the turbines to be ready for 100 percent well before 2045.”

In other words, Ducker said, MHPS expects to make that deadline with significant time to spare. Gas turbines in nearly all their parts can run on hydrogen as well as natural gas, except for the combustion elements.

“Mainly it’s just in how we design the combustors,” he added. “The great news is the compressor, turbines and all other auxiliaries–nothing changes. Some of the piping and valving will be larger, because hydrogen is a smaller gas (molecule) and takes up more volume for the same energy content.”

Controlling the flame temperature is another key adjustment in a possible transition from natural gas to 100-percent hydrogen, and turbines will evolve to a hybrid diffusion/premix-based combustors. Hydrogen-fueled turbines will emit the same nitrogen oxide (NOx) levels as natural gas-fired systems today, but will emit no sulfur dioxide, particulate matter, nor carbon dioxide and will only have a water byproduct.

Sounds simple enough right? Yet hydrogen isn’t drilled right out of the ground, no matter how deep the drill-bit goes. It takes an elaborate process of resource reforming or electrolysis. It’s not cheap but it is energy intensive.

MHPS and Magnum Development have partnered on the idea of building an electrolysis facility near the Intermountain Power Plant around Delta, Utah. The electrolysis–which uses electricity to separate water into its hydrogen and oxygen molecules–would be powered by renewable energy, such as western U.S. solar, wind and hydro. The resulting hydrogen would be stored in underground salt caverns deep beneath the Utah rocky soils.

Ducker estimated that each of those salt caverns potentially could store 150,000 to 200,000 MWh of hydrogen capacity. The area could offer dozens of those caverns, all impermeable and yielding no energy loss.

“Think of it as a really really big battery,” he said.

(Rod Walton can be reached at 918-831-9177 and [email protected]).

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Hydrogen now and future will be part of the content in the Lowering Carbon with Thermal Generation track at POWERGEN International happening December 8-10 in Orlando, Florida.