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enewable energy is creating hydrogen. Near-infrared detectors are distinguishing methane emissions from those of other common chemicals such as butane. Gas heat pump technology is coming to market. Even marijuana-growing facilities are experiencing efficiencies courtesy of combined heat and power and gas heat pump systems.
In today’s competitive, sustainability-driven environment, natural gas utilities are turning innovations into practical products and processes. All are emerging from the never-ending search for breakthroughs that leverage the recognized advantages of natural gas.
The space for hydrogen and green hydrogen is so rich with potential that utilities from local to global are conducting real-world tests expanding the boundaries of sustainability.
“Customers are searching for energy solutions that support their process needs, meet economic targets and increasingly deliver lower-carbon environmental benefits,” said Jeff Householder, president and CEO, Chesapeake Utilities. “While natural gas has long filled those requirements, calls are increasing to do more. Hydrogen may provide a viable energy source that enhances an already enviable natural gas environmental track record.”
Chesapeake Utilities, which is based in Delaware and serves the Delmarva Peninsula and parts of Florida, is among several utilities proposing or implementing innovative projects revealing the possibilities of green hydrogen and hydrogen.
For example, a 20-megawatt gas-turbine CHP plant operated by Chesapeake’s subsidiary Eight Flags Energy for a Florida industrial site “provides a unique opportunity to assess the feasibility and operating characteristics of blended hydrogen and natural gas in a contained and closely monitored industrial setting,” said Householder.
Under a related Chesapeake initiative, the company’s Marlin Gas Service tankers will transport hydrogen to the Chesapeake-owned gas distribution system at the CHP site. After delivery to an isolated, specially constructed interconnection, the hydrogen will be blended with natural gas and then sent to the CHP facility through existing stainless steel service mains.
The dual test will build understanding of blended-fuel gas facility operational practices and safe transportation and injection of hydrogen into gas distribution systems.
Capping off the project, partner Solar Turbines will assess the impact of the hydrogen blend on operations of the turbine and other CHP equipment. With its experience utilizing hydrogen in field-installed turbines, Solar Turbines has applied for U.S. Department of Energy support, backed by Chesapeake’s offer of Eight Flags CHP as a test site. Testing will proceed regardless of DOE status, but participation by the department “would expand the testing protocols and instrumentation, ultimately providing data beyond our internal process,” said Householder.
While the 4% blend projected for initial tests will not be green hydrogen, company officials will contract for it if DOE support comes through or they decide to utilize a hydrogen blend permanently, said Householder. A “real possibility” exists for increasing the blend to as high as 10% to 12%, in part because the replacement turbine scheduled for a 2022 changeout will be capable of accepting higher percentages of hydrogen.
Chesapeake Utilities aims to help its large-volume industrial customers better manage carbon emissions by offering hydrogen-blended fuel, technical assistance and training, and investments in the equipment customers need to accept hydrogen. Initial efforts are focusing on industrial users, but, in time, hydrogen blends in distribution systems could be used by all customers.
“Hydrogen, along with renewable natural gas, conservation, carbon capture and other emerging technologies, will ultimately provide customers with increased sustainable energy choices,” said Householder.
Meanwhile, Connecticut-based AVANGRID, part of Spain’s IBERDROLA group, is striving to enable clean hydrogen at scale through projects at Avangrid Renewables and Avangrid Networks. The company has submitted five U.S.-based green hydrogen proposals to the DOE, focusing on electrolyzers that create green hydrogen from water, hydrogen storage and hydrogen for transportation; leveraging wind generation to develop green hydrogen and green ammonia; and co-locating green hydrogen with cogeneration.
The demonstrations hope to showcase hydrogen’s scalability and value. Avangrid Renewables will evaluate optimal electrolyzer operations, and the renewable generation that powers them, to improve economics and teach new skills to the workforce. Projects at Avangrid Networks, which owns eight electric and natural gas utilities, expect to leverage utility-customer relationships to determine which end-use applications, such as heavy transportation and high-temperature industrial processes, have the highest potential for demand, while evaluating the use of storage and infrastructure to meet that demand.
The size and scope of the projects also target cost reductions by creating economies of scale, “such as through greater industry investment in electrolyzer manufacturing,” said Manuel Gonzalez, senior vice president with responsibility for clean hydrogen projects.
The Biden administration has set a goal of bringing the cost of green hydrogen—now at about $5 per kilogram—to $1 per kilogram by 2030, closer to gray hydrogen’s current costs of $1 to $2 per kilogram. With its DOE submissions, AVANGRID has its sights set for funding through DOE’s Energy Earthshots initiative. “Achieving the U.S. DOE’s milestones will require investment by both the public and private sectors to reduce the cost of electrolyzers and the renewable energy powering them, as well as to increase the load factor of electrolyzers,” said Gonzalez.
AVANGRID expects to leverage lessons learned from IBERDROLA, whose current green hydrogen projects include partnerships to install electrolyzers in Spain and green hydrogen production in the U.K. for heavy-duty mobility. “AVANGRID believes that green hydrogen will play a major role in the path to net-zero by 2050 by enabling the decarbonization of sectors that currently consume gray hydrogen, such as ammonia production, and sectors that are difficult to electrify, such as heavy transportation or high-temperature industrial processes,” said Dennis Arriola, CEO, AVANGRID.
As IBERDROLA estimates, replacing gray hydrogen with green hydrogen for existing demand could equate to saving more than 800 million metric tons of annual carbon dioxide emissions globally.
Closer to home, research and manufacturing are ensuring that another innovation—the residential gas-driven heat pump—is building toward wide-scale implementation.
“Based on our current efforts and projections from our manufacturing partners, we can say that by 2024, being a bit conservative, people should be able to purchase these kinds of equipment to replace their furnace, boiler and/or water heater,” said Paul Glanville, research and development director, GTI.
Research and development into residential gas heat pumps began ramping up in the early 2000s, with support from the DOE, Northwest Energy Efficiency Alliance, the California Energy Commission and the Utilization Technology Development NFP, a utility-funded, not-for-profit research organization. In 2019, a group of utilities also created a gas heat pump road map, which “set the stage for a lot of bigger efforts underway right now,” said Glanville.
Still, impediments to large-scale market transformation have included product availability, lack of feedback loops that expose contractors to training and education, the technical challenges of scaling down complex fuel-fired equipment, and inexpensive gas that extended payback periods for high-efficiency equipment.
Recently, prototype demonstrations and tests have shown significant energy savings of 40% or greater, as well as GHG reductions, with absorption-type gas heat pump technologies, applied in space and water heating. Now, building off that road map, GTI is working with utilities on a large-scale residential gas heat pump demonstration project across 50 North American sites.
In partnership with a large original equipment manufacturer, Rinnai America Corporation, the project aims to develop a pre-commercial gas heat pump leading directly to a commercial version. Despite pandemic-related delays, “that’s a really promising development for the commercialization of the product,” said Merry Sweeney, senior market analyst, GTI.
Decarbonization goals are what are driving residential gas heat pumps toward the finish line. It’s true that the ability of gas heat pumps to reduce energy usage and GHG emissions depends on many factors, including technology type and operating conditions. But studies have pointed to gas heat pumps as the lowest-cost, lowest-carbon approach for certain HVAC and water heating needs, and they can reduce fuel consumption by 40% to 50% for water and space heating, while consuming slightly more electricity for operation than the traditional furnaces or water heaters that they’re replacing.
Technology that significantly reduces energy consumption, retrofitted throughout North America’s vast housing stock, offers an opportunity to “really move the GHG reduction needle,” said Rich Kooy, director, UTD Operations, and senior institute engineer, GTI.
Still, research continues into such questions as the impact of ammonia—a prime refrigerant—on some equipment or practices. But ammonia is allowed under technical standards made by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, or ASHRAE, and others. It is also a natural refrigerant with a Global Warming Potential rating of zero that will likely become much more commonly used. In addition, controls, installation and maintenance procedures also require updates. “It’s complicated,” said Glanville. “It takes a whole industry to roll up their sleeves.”
Gas-fired heat pumps can currently find a niche in areas where peak energy consumption or operating costs are a concern. Retrofitting older commercial buildings that lack the power distribution to handle large chillers is another niche, particularly in the Northeast. But the upcoming products are targeted for widespread application and impacts in homes and small businesses. And GTI’s pilot tests of gas heat pumps replacing furnaces and water heaters in single- and multifamily homes in cold climates already show promise. Customers “are still quite comfortable,” said Glanville.
Kooy added, “These units perform when it’s super-cold out, so not only are they efficient, but they deliver.”
In the meantime, new technologies and processes are also enabling improved emissions detection at home, with several utilities working proactively to pilot-test these devices.
Today’s long-life, methane-sensitive gas emission detectors have overcome the problems of older-generation models, whose catalytic sensors often could not distinguish methane from other chemicals found in homes, such as butane and propane.
Newer semiconductor-based detectors have improved sensors and use filters and sophisticated algorithms to avoid false-positive responses. The newest generation of detectors offers near-infrared spectroscopy to detect methane’s unique signature on the light spectrum. “As long as you pick that right spectral band, you’re not going to get any interference from other household chemicals,” said Karen Crippen, director, energy supply and conversion, GTI.
In one example, French sensor company eLichens has developed a nondispersive infrared sensitive enough “to detect methane, and only methane,” said Maxime Vincent, sales marketing manager, eLichens. “It’s not sensitive to butane, propane and other gases close to methane, to avoid false alarms.” During the sensor’s development, eLichens also overcame the challenge of optimizing the sensor so that its battery could operate 24/7 at a level low enough to extend battery life to 10 years—a longstanding industry goal, the company claims.
That sensor is now inside eLichens’ connected, low-power avolta detector. Installed near gas meters, eLichens states its signals are strong enough to project through basement walls and transmit data wirelessly to utilities through the LoRaWAN communications protocol—the low-power, Long Range Wide Area Network that integrates with the Internet of Things.
Research is also uncovering other new processes and applications that could further improve detectors—for example, combining detectors with automated shut-off valves to block the flow of gas into systems or structures when sensors detect methane, said Crippen. And while current methane detector technology follows the UL 1494 standard to issue alarms when detecting 25% of methane’s lower explosive limit, or LEL, GTI is recommending a downward revision to 10% LEL, said Crippen, based on recent research results. GTI maintains lowering the alarm limit would align more closely with the level at which human smell can detect natural gas’s odorant and allow detectors to sound sooner.
Meanwhile, utilities are pilot-testing methane detectors for their sensitivity, longevity and integration with open-ended communications networks, such as LoRaWAN, Landis+Gyr, ITRON network and cellular connectivity, as well as installation instructions and placement.
For example, both National Grid and Con Edison are using sensors from eLichens in detectors that they are pilot-testing. Tests of three devices at National Grid are seeking the path to scalability, aiming for broad distribution within a few years, said Pradheep Kileti, director, future of heat engineering and R&D program management. The tests have already shown successful results on the sensitivity side and are now probing communications capabilities across several networks. “First, it should detect what it is supposed to detect,” said Kileti. “The second goal is making sure that when there is detection, the information comes to us. The system should be reliable. It should be small and robust.”
National Grid is working with manufacturers on sensor longevity that matches the battery in order to build detectors that, once at scale, can be cost-effectively replaced every 10 years, said Kileti. In the tests, underway with about 1,000 residential and small commercial customers, the utility and manufacturers are also collaborating on development of installation instructions simple enough for property owners to follow that can perhaps be delivered via QR code.
Under current thinking, National Grid is not testing detectors with valve shut-off capabilities because control centers, once alerted to possible emissions, can direct new-generation smart meters to halt service, said Kileti.
At Con Edison, testing now underway is driving toward the goal of placing detectors in every structure, preferably at no charge to property owners, said spokesperson Philip O’Brien. In addition to testing detectors for communications and sensitivity, Con Edison is testing the advantages of battery power versus electric, O’Brien said.
Some methane detectors have been “surprisingly successful” in trials, he said. In one instance, fire department responders arrived at a building before the homeowners got to the phone—anecdotally supporting the logic of relying on IoT-connected methane detectors to save precious time in emergencies.
Innovations fueled by natural gas have the potential, promise and possibility of powering our world in new and surprising ways. Natural gas is also highly versatile, and as utilities, manufacturers and researchers are demonstrating, versatility is what provides the springboard for innovations that can continue to firmly place natural gas as a key player in the energy mix of the future.
A Unique Market
In 2009, Tommis Young, director of Blue Mountain Energy, was marketing the gas heat pump technology he had perfected in the desert of Nevada, targeting municipalities and commercial applications. Around 2013, engineers started requesting specs for cannabis-growing facilities—and Young became intrigued.
“It is now our largest market segment that we sell product into,” he said. “Out of all the equipment we sell, 80% is probably for the grow industry.”
Inadvertently, Young had tapped into a $61 billion U.S. market that’s projected to reach $100 billion by 2030. His gas engine-driven heat pumps address two unique features of the facilities where legal medical and recreational marijuana is grown:
Infrastructure: Tremendous heat is generated by grow lights. While 1 ton of cooling can air-condition 200 to 250 square feet of a typical commercial building, the rate in grow facilities is only about 50 square feet per ton. The difference in requirements “is all because of the lighting load, since all the electricity put into the light creates heat,” said Young. Additionally, many applications are electrically constrained, which can restrict the square footage that a grower can develop for operations. Using gas heat pump technology for cooling frees electric allotment for lighting. If used with combined heat and power, the technology further reduces the amount of electric generation required.
Operating costs: One 15-ton gas engine-driven heat pump uses as much electricity as a hair dryer, for net operating cost savings as high as 60% of electric, depending on local utility costs, said Young. Lower costs mean higher profit margins per pound of product grown.
Plus, combining a gas heat pump with a natural gasfired generator can create CHP capabilities. An applied solution can capture the waste heat of the separate unit and generate electricity, which can then be used to displace electricity otherwise purchased from the grid or for any supplemental purpose—space heat, domestic water, hydronic uses, even snow melt. An off-grid unit for combined heating, power and cooling in commercial applications that utilizes gas heat pump technology is in early development, Young said.