Hydrogen technology in gas boilers – when will hydrogen replace natural gas?

With an expert eye

Anna Pawłowska-Kawa, specialist in the field of ecological heating devices

The heating industry has encountered numerous challenges recently, leaving consumers perplexed with the conflicting information surrounding various heating devices. The debate around gas boilers resurfaces periodically, raising questions about their potential ban and timing. However, in Poland, gas boilers continue to benefit from subsidies, including support from the Clean Air Program. Surprisingly, despite the ongoing discussions, gas boilers remain the second most popular choice for heating devices, following heat pumps acquired as part of thermal modernization support.

In early December 2023, the EU Council and the European Parliament reached an agreement on the EPBD directive, outlining a specific timeline for transitioning from fossil fuels to renewable energy sources, particularly heat pumps, for heating and cooling buildings. While this move towards renewable energy is laudable, some experts caution against a hasty departure from gas, citing potential disruptions in the energy market. Gas, alongside nuclear energy, is considered one of the most reliable energy sources due to its stability and independence from weather conditions, though geopolitical factors are not considered here. Hydrogen, often touted as the fuel of the future, could offer a solution to ensure both energy security and a shift away from fossil fuels, not only for transportation but also for heating purposes. However, while hydrogen adoption in transport is progressing with hydrogen cars and buses already on the streets, its widespread use for district heating or home installations poses greater challenges.

The biggest challenges for hydrogen technology in heating

Hydrogen faces several challenges when compared to natural gas, starting with its lower calorific value in volume terms, which is three times less than natural gas. Additionally, hydrogen has a much higher flame propagation speed, increasing the risk of spontaneous combustion. Another concern is the phenomenon of flashback, where the flame travels back into the device, a risk present in all heating devices but particularly hazardous in gas or hydrogen boilers.

Moreover, integrating hydrogen into existing transmission systems requires extensive modernization of the fuel supply infrastructure to accommodate its unique parameters. This includes managing increased flow rates and addressing hydrogen embrittlement, where hydrogen atoms penetrate and weaken metal components over time. Additionally, there’s a need for specialized expertise in hydrogen technologies, highlighting the challenge of developing and training a skilled workforce in this field.

Pioneering hydrogen heating projects

Despite numerous technical hurdles, pilot programs featuring boilers powered by 100% pure hydrogen or hydrogen-natural gas mixtures have been underway in Europe for years, led by countries like Great Britain, Germany, and the Netherlands. In the UK, hydrogen technology has been a focal point since 2008, with initiatives like the Keele University campus using a gas network incorporating a 20% hydrogen blend. Similarly, the town of Winlaton implemented a network covering nearly 700 buildings, including residential and public facilities. Notably, the RAF military base in Spadeadam has been powered by clean hydrogen since 2020, showcasing its versatility in providing heat and powering appliances. Research on hydrogen leak risks is also underway, comparing them with methane leaks.

In late 2022, Great Britain contemplated a complete ban on traditional gas boilers by 2026, favoring those equipped with H2 Ready technology, designed for seamless conversion from natural gas to hydrogen. This proposal sparked debates among politicians, economists, environmentalists, boiler manufacturers, and the energy industry. Former Prime Minister Boris Johnson was a vocal advocate of hydrogen technologies, viewing them as pivotal for decarbonizing the domestic energy sector.

The enthusiasm for hydrogen technologies in the UK has faced a setback under the new Prime Minister, Rishi Sunak, who sees fossil fuels as indispensable for meeting energy demands. Sunak has delayed plans for climate neutrality and issued hundreds of new licenses for oil and gas exploration, relaxing emissions regulations. Meanwhile, in the Netherlands, an experimental network featuring a community hydrogen boiler plant (powered by 100% H2) has been operational since 2019. Developed by BDR Thermea Group, Beakert Heating, and Enapter, the system utilizes eight electrolysers to produce hydrogen, which is then supplied to the gas boiler room serving 25 apartments. The project involved retrofitting the existing natural gas pipeline to transport green hydrogen onsite. After 3 years of operation, a recent maintenance check confirmed the excellent condition and uninterrupted efficiency of the 100% hydrogen boiler, showcasing its reliability. Andrea Manini, head of the hydrogen and fuel cell program at BDR Thermea Group, expressed pride in the boiler’s performance, emphasizing its importance in advancing hydrogen technology.

The successful development of highly efficient and safe hydrogen-burning devices by manufacturers like BDR Thermea Group sets a precedent for the industry. Other gas boiler manufacturers have followed suit, focusing mainly on the “H2 Ready” design, which enables the burning of natural gas with a hydrogen admixture, typically 20% or 30%. These boilers are designed for easy conversion by authorized service technicians. While a 20% hydrogen admixture may seem insignificant, research in Great Britain indicates otherwise. It suggests that using natural gas with 20% hydrogen could have a significant environmental impact, equivalent to removing 2.5 million cars from the roads and reducing greenhouse gas emissions by approximately 8% annually.

Is Poland ready for hydrogen?

To ensure that the transition to hydrogen is not only environmentally beneficial but also economically viable, it’s crucial to leverage and adapt existing gas transmission networks and installations. In Poland, until August 2022, regulations prohibited any hydrogen content in natural gas. However, a recent amendment now allows for a maximum of 10% hydrogen in natural gas, marking a significant legislative step towards introducing hydrogen into the energy mix.

Concrete projects are beginning to take shape as well. SES Hydrogen Energy, for instance, plans to construct the first hydrogen boiler house in Poland for residential buildings, along with all the necessary infrastructure. This facility, to be located in Śrem on ul. Farna, will feature a hydrogen boiler room fueled by the combustion of hydrogen and oxygen, as well as a heating installation incorporating brine-water ground heat pumps.

The European Green Deal emphasizes the importance of local governments achieving self-sufficiency, and district heating systems play a significant role in this transition. Sanok, a city in Poland, is poised to serve as a model for this shift. In 2021, the Podkarpacka Hydrogen Valley initiative was launched, spearheaded by Sanocki Przedsiębiorstwo Gospodarki Komunalnej (SPGK), aimed at decarbonizing the city’s heating sector. Currently, Sanok relies on two coal-fired heating plants, but plans are underway for a transformation. “We are investing in a biomass boiler and temporarily using a gas boiler, but our ultimate goal is to transition to hydrogen,” explained Krzysztof Jarosz, president of SPGK. The comprehensive plan includes the installation of photovoltaic panels, electrolyzers, energy storage systems, an electrode boiler, and a heat pump. Waste heat from the electrolyzer will also be utilized in the heating system, showcasing a holistic approach to sustainable energy transition.

Hydrogen is not equal to hydrogen

Hydrogen is categorized by colors based on the method of production, each with its environmental implications:

• Gray: Produced from fossil fuels like coal or natural gas, emitting CO2 into the atmosphere.
• Pink: Generated using electricity or heat, often from nuclear energy.
• Blue: Derived from fossil fuels but with CO2 capture and storage.
• Turquoise: Created through methane pyrolysis, requiring renewable energy for heat.
• White: Naturally occurring geological sources.
• Green: Produced via water electrolysis powered by renewable energy.

Currently, the majority of hydrogen production worldwide is gray, originating from industrial processes. However, there’s a growing interest in white hydrogen due to its natural abundance. Discoveries of white hydrogen deposits have been made in various countries, including the USA, Russia, and Mali. In 2023, France unveiled significant white hydrogen reserves, sparking global attention. While green hydrogen has been prioritized for its eco-friendliness, the high production costs and limited supply may shift focus to white hydrogen if ample and accessible deposits are found.

Hydrogen technology in gas boilers – summary

The transition away from fossil fuels is inevitable, yet there’s still a notable interest in gas boilers among Poles, evident in applications to programs like the Clean Air Program. While heat pumps were popular in 2022, there’s been a resurgence in gas condensing boilers in early 2023. EU regulations set a timeline, prohibiting the installation of gas boilers in new buildings by 2027, and in modernized properties three years later.

Additionally, the Ecodesign Directive mandates that from 2025, all new gas appliances must accommodate a 20% hydrogen blend, with full hydrogen compatibility required by 2029. However, the readiness of our infrastructure to transmit hydrogen remains uncertain. Nonetheless, hydrogen technology presents an interim solution for a smoother energy transition, with biofuels like biomethane or bioLPG also expected to play a role in filling the gap left by natural gas.

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