By Ellie Martin
The 2021 Sustainable Gas Institute Annual Lecture was delivered on 3 December and focused on hydrogen’s role in heating. It was contextualized by the challenges to decarbonizing heat, a comparison of hydrogen boilers and heat pumps, the importance of listening to consumers, and the steps that need to be taken to achieve net-zero gas with the help of hydrogen. Content was delivered by the engaging Dr. Angela Needle, who serves as strategy director at Cadent Gas, founder of the Women’s Utility Network, and VP of the Hydrogen UK Trade Association.
Challenges to Gas Alternatives
Given the impending state of climate change and a 300 TWh yearly dependence on natural gas for domestic heating, it is clear that decarbonizing gas is key to achieving net zero emissions for the UK by 2050. Fortunately, a few alternatives to natural gas are inching across the market – namely heat pumps, district heating, and now potentially hydrogen. Current gas boilers are reliable, easily tucked into cupboards and other discrete areas, easy to control and adjust, and generally problem-free. These are some big shoes to fill. What’s more, over £11,000 per home would be needed to cover the energy efficiency improvements, appliance replacements, and electricity and gas network changes necessary for net zero gas. On top of this, homes in the UK are quite literally the worst in Europe when it comes to retaining heat. UK homes lose an average of 3°C over five hours (surpassing all European neighbors), with 61% of EPC ratings falling at or below the D level.
There’s also the difficulty of determining who owns buildings, with the UK moving towards outright ownership. This is a huge challenge to achieving net zero because homeowners are the hardest to reach when it comes to government policy. Diversity in ownership types also presents an issue: solutions will need to be tailored to each property instead of adopting a one-size-fits-all policy.
Heat Pumps vs. Hydrogen Boilers
An all-hands-on-deck approach will likely be required for natural gas replacements, particularly during the early stages of development when it is unclear which technology will turn out to be the best investment. While hydrogen boilers and heat pumps are often unfairly pitted against each other, there are some key differences between the two that bear mentioning.
One of the most obvious advantages to heat pumps is that they’re currently deployable and proven to work. They’re also highly efficient and thus a good fit for well-insulated homes, and the low energy requirements afforded by these high efficiencies can produce lower running costs. Downsides to this technology include its high upfront cost, supply chain limitations, and the need for consumers to change their behavior.
On the flip side, hydrogen boilers are expected to cost around the same amount as gas boilers and could fit in the same exact spaces, and thus the switch would require less adaptation by consumers. They don’t need to rely on electricity at critical times of the day due to the capacity for storage, and they don’t produce any carbon monoxide. However, hydrogen boilers are not yet commercially available and could temporarily increase gas prices during the initial scale-up stages. Another issue is public perception, namely safety concerns regarding flammability and a general view that these systems are inefficient because energy is required to make hydrogen, and hydrogen is required to make heat.
Since the two options excel in different areas, one technology might be a better fit for a given context. For this reason, it is important to approach deployment from an individual building level in addition to a national level. Resilience network planning will also be key to ensuring constant delivery, even in extreme circumstances like disruptive storms.
The Importance of Consumers
Decarbonizing gas is going to require a highly inclusive approach that considers technical, economic, and consumer perspectives. This last bit is especially important, as consumers tend to be left by the wayside when it comes to big picture solutions. And despite reports that 75% of the public is concerned about climate change, there is still a massive gap between public intent and public action – for example, only 39% of people have reported considering a switch from natural gas heating. Because the effort required to implement new technologies can be a major barrier to uptake, it is crucial for governments to make it easy for consumers to commit to action. A key part of this involves educating consumers with the help of trusted advisors, such as local tradespersons and NGOs, as opposed to energy suppliers or natural gas companies (for whom consumers are typically much less responsive).
Planning the Future
Cadent is working on a range of projects related to net zero gas, and I was particularly impressed by their implementation approach, which is essentially this: don’t expect people to be comfortable with technologies they have to imagine, show them what’s possible. For example, one project is developing in-home applications for hydrogen: whether an odorant needs to be added, where hydrogen accumulates if it leaks, and how readily combustible it is, among other questions. An exciting product of this work is a hydrogen show home that has cropped up in Gateshead. The house features hydrogen boilers, stoves, and fires that boast a beautiful orange flame (to book a visit, email firstname.lastname@example.org ). Project “H21” is testing the feasibility of 100% hydrogen supply up and down the UK’s current gas network, and another scheme involves blends of hydrogen and natural gas that can provide CO2 emissions reductions of around 6% and could serve as a key stepping-stone in scaling up and encouraging public acceptance of 100% hydrogen in the near future. Residents who participated in this project consistently reported that they couldn’t tell the difference between regular and blended boilers.
So how much hydrogen do we theoretically need? According to predictive models, this number varies from 23 to 182 TWh depending on the interplay between customer acceptance of hydrogen and the adoption of heat pumps. While it’s difficult to plan for a future that has so much uncertainty, the gas sector can prepare by ensuring hydrogen is as safe, well-planned, and easy to implement as possible for when the time comes to deploy. If companies like Cadent continue to innovate in this direction, hydrogen has my full support.
Ellie Martin is a master’s student in Imperial’s Sustainable Energy Futures course. Her undergraduate background is in Biochemistry and Molecular Biology at the University of Miami, and she’s interested in developing energy technologies through the intersection of engineering and molecular science.