Natural gas-fired plants have been a go-to electric generation source as coal retires. Natgas reduces greenhouse gas emissions by over 50% as coal to gas switching in the US has become a generating reality. But carbon, in the form of CO2 remains an issue. And for gas turbines, one real opportunity to drive down CO2, in addition to Carbon Capture Utilization & Sequestration (CCUS), is the potential of hydrogen as a zero-carbon fuel.
By mixing hydrogen with natural gas (at some level) to run electricity-producing turbines, the opportunity begins.
It is not a simple exchange of fuels. “It’s not like switching from 87 to 89 octane gasoline in a car,” says Sal DellaVilla, Managing Director of the Gas Turbine Association. DellaVilla is also the CEO of SPS, a Charlotte-headquartered company that works with energy producers to manage their running reliability and availability data.
Energy Consumers talked with Sal about the future and the challenges of mixing hydrogen and natgas to make power and reduce emissions.
Bottom line: Hydrogen helps reduce carbon emissions. “The difference between natural gas and hydrogen is this: Methane, a greenhouse gas, is a major constituent of natgas. Hydrogen is H2, a predominant element in the world with water. Hydrogen as a potential fuel has a benefit – zero carbon,” says DellaVilla.
By mixing hydrogen with natural gas, CO2 emissions are reduced compared to using natural gas alone. “Today the focus is on a hydrogen blend in the 10-20% range,” DellaVilla says. “We want to use using existing gas turbine technology, the paid-for and working plants in place, to get a benefit.”
To increase the mix of hydrogen, or go 100% hydrogen, will take more research and likely new hardware.
Policymakers hear about hydrogen and are interested. DellaVilla says communicating the challenge of increasing the mix of hydrogen with natgas is more than technical, though. “Successful communication is a formula. Intellect results from science over emotion.”
The Gas Turbine Association is building collaboration between stakeholders to increase grid resilience and reduce greenhouse gasses. DellaVilla addresses four issues as he educates people about the gas/hydrogen transition. The conversation normally raises four important points:
Color: What process is used to produce hydrogen? Or, what color is the hydrogen – brown, blue, green – referring to the way it is made. Green hydrogen is the ideal. Green H2 is made through electrolysis of water – sending an electric current through water to split hydrogen atoms from oxygen using clean energy. Blue H2 uses natural gas, steam methane reforming, plus carbon capture and storage – more involved. Making enough green hydrogen is the challenge. The key is that the process is also tied to the economics.
- Infrastructure: Ensure that the nation has the framework to produce, store, and deliver hydrogen in the required volumes and pressures. For example, does the current infrastructure support the introduction of hydrogen (at what %). Making our current infrastructure hydrogen-friendly and ready is the challenge.
- Volume is also a question. The volume of hydrogen required is 3 to 4 times more than Natgas for the same energy output. Do we have the storage and shipping capacity and capability?
New technology: Hydrogen is not a “drop-in” fuel for current natural gas fired plants. Changes in fuel handling systems, valves, and more importantly the combustor and turbine hardware require R&D investment to drive change and control emissions, costs, and operations. That is for 100% hydrogen use.
Safety is a focus. Operating practices, and industry standards must also evolve to accommodate the need for safety. Very important emphasis.
There is the cost to make hydrogen, too, which needs to drop anywhere from 60-80% to be competitive today. Accelerating research and deployment of new tech is a challenge that will have to be met to make hydrogen cost competitive.
Operating profile – the importance here is operating flexibility to ensure the reliability and durability of the asset. This is an essential requirement as the asset must be able to meet the operating demand of the owner/operator.
Hydrogen gets a lot of press, not only as a fuel to make electricity for homes and businesses, but also for fuel cells for vehicles and even to fly jets. Hydrogen also checks another box as our society adds renewables like wind and solar. Many renewables have varied output depending on the weather. Stability of power output can be hydrogen’s strength as it is stored and reconverted into carbon-free power on demand.
What about utilities and hydrogen? S&P Global reports there is action. Despite the lack of a national hydrogen plan, U.S. utilities have communicated their nascent ambitions in the technology. Among them:
- Dominion Energy, Inc. is currently in the first phase of testing a 5% blend of hydrogen in an isolated gas distribution system at a Salt Lake City training facility. It intends to incorporate hydrogen more widely and eventually increase the percentage in the system.
- Duke Energy Corp. is researching hydrogen production, hydrogen storage, and co-firing hydrogen with natural gas at its power plant at Clemson University in South Carolina.
- NextEra Energy Inc. is investing $65 million in a project that will use excess solar energy to produce hydrogen for its Okeechobee natural-gas plant. The 20 MW electrolysis system is expected to come online in 2023 and will replace a portion of natural gas.
- Others: Arizona Public Service Co., Exelon Corp., and Xcel Energy Inc. are individually piloting projects that will demonstrate hydrogen production from the companies’ non-emitting nuclear power plants.
Feature image: Duke Energy’s Lincoln Combustion Turbine Station near Denver, N.C. This is a station that is exploring new ways to operate in conjunction with Siemens Energy. The new unit added was synced to the grid for the first time in May 2020, and a four-year testing process (2020-2024) is underway. NOTE that while this plant has turbines and uses natural gas, do not consider that it is doing hydrogen research. The image is being used to show a gas facility.