The power sector is transforming. Global demand for clean energy is increasing, renewables are being brought online faster than ever and emissions regulations are tightening.
This evolution is coupled with advances in digital intelligent data platforms and energy storage.
A panel of experts, which included representatives from leading gas turbine OEMs, took part in a Mega Session discussion at POWERGEN International in Orlando in February to break down these realities and highlight the future role of the gas turbine, considered the workhorse of power generation.
“I view the gas turbine, from a power plant perspective, as the ultimate energy conversion chameleon,” said Jeff Benoit, V.P. of Clean Energy Solutions for Power Systems Manufacturing (PSM). “It’s been tasked with doing many things: baseload power, cyclic, peaking, with different types of fuels.”
Unsurprisingly, the conversation focused largely on hydrogen. Fuels like hydrogen and ammonia can be used in gas turbines for decarbonization and to increase power system flexibility.
Hydrogen and energy have a long shared history. Jeff Goldmeer, emergent technology director for decarbonization at GE, noted the OEM has older units with more than 100,000 hours working with hydrogen fuels.
“If you get folks who say to you, ‘are you really sure you could burn hydrogen in a gas turbine?’ There is only one answer, and the answer is ‘yes,’” he said.
For the speakers on the Mega Session stage, the obstacles associated with combusting hydrogen in a gas turbine have little to do with the gas turbine technology itself, but rather the infrastructure, supply chain, economics and the availability and supply of hydrogen.
Goldmeer highlighted several hydrogen demonstration projects using GE turbine-equipped plants.
At New York Power Authority’s Brentwood Power Station in Long Island, Goldmeer said GE took its LM-6000 unit to 44% hydrogen with no changes to the engine itself.
“The gas turbine, from an operational perspective, didn’t care the hydrogen was there,” he said. “We were able to run [the gas turbine] and stay within the operating permit for NOx, see lower CO and maintain the same ammonia output.”
Another plant, The Long Ridge Energy Terminal Power Plant in Hannibal, Ohio, ran a roughly 5% hydrogen blend during a demonstration last year. The 485 MW combined-cycle gas turbine (CCGT) plant is powered by a GE 7HA.02 turbine.
Goldmeer said the unit could have run at about 20% hydrogen, but was ultimately limited by hydrogen supply, a common challenge noted during the panel discussion.
“We ran roughly a 5% blend that was two tube trailers,” he said. “It wasn’t quite as fast as a snap of your fingers but less than an hour of operation. Supply is really just an issue.”
Also taking part in the panel was Mark Bissonette, who is executive V.P. and COO for power generation at Mitsubishi Power.
“When I started in this industry, we were worried about how to manage an F-class boom,” said Bissonette. “And here we are talking about what we’re going to do 10, 15, 25 years from now today.”
Last spring, Mitsubishi Power validated a 20% hydrogen blend at both partial and full load on an M501G natural gas turbine at Georgia Power’s McDonough-Atkinson plant in Smyrna, Georgia. At the time the company reported this blend provided a roughly 7% cut in carbon emissions compared to natural gas.
On the McDonough demonstration, Bissonette said: “[Hydrogen] availability was key and I think we ended up trucking from a couple states away, which was also another challenge.”
“You ask for a tube trailer of hydrogen, and multiples, and [gas companies] start crying uncle,” added Goldmeer. “Because in many cases, you’re asking them to supply their entire volume of hydrogen supply, or you’re asking them to resupply at a rate they can’t.”
Significant hydrogen storage could help with the curtailment of renewables. Mitsubishi Power is developing the Advanced Clean Energy Storage Hub in Delta, Utah, a facility expected to be capable of providing long-term, seasonal energy storage.
The facility will combine 220 MW of electrolysis with two massive 4.5-million-barrel salt caverns to store clean hydrogen captured from renewable energy. Each cavern is the height of the Empire State Building.
The hydrogen would then be deployed as fuel for the Intermountain Power Agency’s (IPA) IPP Renewed Project—a CCGT plant intended to be eventually be fueled by 100 percent hydrogen by 2045.
Bissonette said he believes this hydrogen hub project will help reduce the cost of hydrogen –by getting other sectors involved.
On the challenge of hydrogen supply, Benoit said the industry should focus on the lowest hanging fruit for applicable use.
“My thesis is that we start small,” he said. “Let’s look at the smaller gas turbines, those peakers, those in cyclic application in the right spots, those that have access to refinery off-gas, where you cannot flare, but you have an existing power plant that’s available.”
Pratyush Nag, who is managing director for controls & digitalization at Siemens Energy, said gas turbines will have to provide residual load in grids largely dominated by renewables.
“Intermittency is the problem that we need to solve today,” he said. “That is the point of where we are in the journey toward decarbonization.”
Nag highlighted the Lincoln Combustion Turbine Station in Charlotte, North Carolina, which last year was certified as the “most powerful simple-cycle gas power plant” with the Guinness World Records.
The plant is powered by a Siemens Energy SGT6-9000HL turbine and will be turned over to Duke Energy in 2024.
“This unit can get on the grid from sync to full load: 400 MW in five minutes,” said Nag. “That’s the resolution of the problem you’re trying to solve, which is, how do we get on the grid quickly to solve the residual load issue.”
Nag said the plant can blend up to 50% hydrogen already.
“What we are looking into is how can we get a sustained, continuous operation, that’s what’s important,” Nag said, when asked about the future of hydrogen-combusting power plants. “That could be offtake from a refinery, it can be a byproduct from different aspects. It can be different solutions. That’s the space we need to explore.”
All the speakers agreed that now is the time for unprecedented collaboration as the power sector races to meet net-zero goals.
We all compete against each other, but more than ever, you see a lot on collaboration,” said Bissonette. We’re working with groups that we’ve never worked with as an OEM.”
He added: “The economic model doesn’t always pencil out at the beginning, but what’s important is that we’re learning from each other in order to facilitate that decarbonized platform.”
This post appeared first on Power Engineering.
