The popularity of hydrogen has increased ever since more people are aware of its environmental upper hand. I mean, who doesn’t like an energy-rich gas which releases no carbon emissions when burned?
We now know that we can use it in most equipment which uses natural gas (methane) or LPG (liquefied petroleum gas). In homes of areas of temperate climate, such equipment might mean a gas boiler, heater, cooker or all three.
In a bigger scale, hydrogen can also power combustion-engine vehicles which might otherwise run on petrol. And it can generate enough heat for heavy industry processes such as steelmaking. As for now, heavy industry machines are still mostly powered by coal.
However, should we (and can we) use it to heat our home and completely replace the other not-so-eco-friendly energy?
An element with good environmental benefits… in theory
Hydrogen is one of the most abundant elements on Earth. However, because it reacts so readily with other elements, there is very little pure hydrogen available. That’s why we have to extract and store it if we want to use it.
There have been new developments and methods to produce green hydrogen, but not in a large scale. Besides, the necessary infrastructure to produce it hasn’t had sufficient incentive. For now, most hydrogen production relies on fossil fuels—about half of it from methane, while the rest from oil or coal.
And since it still depends on fossil fuels, the extraction and production releases carbon. Therefore, the vast majority of hydrogen still has a “grey” label, as it still involves emitting carbon to the atmosphere. In the end, it’s not a real green energy, as its production contributes to global warming.
That’s why, some experts are still skeptical about going green by using hydrogen in households.
Risks of hydrogen in homes
While hydrogen is a good candidate to be a green substitute for fossil fuels at home, we won’t have it any time soon.
For one, it’s naturally riskier. Compared to methane, hydrogen is a smaller and much more flammable molecule. And, some experts believe that it can leak climate-warming compound through pipes and embrittle them, accumulating in enclosures or in the atmosphere. In homes, that may potentially cause explosions.
Therefore, experts say that any gas utility aiming for 100% hydrogen would need to upgrade its distribution system depending on each pipe’s age, size, material, and operating pressure.
Then, household appliances are currently optimized for natural gas, and are generally incapable of safely handling more than a 5%-20% hydrogen blend.
To switch to hydrogen, according to some experts, we would need to develop household equipment and appliances capable of handling pure hydrogen, pure natural gas, and any blend in between.
Utilities would then need to coordinate replacing every single appliance in their service area before increasing their blend beyond 5%-20% as any missed appliances would cause an explosion.
What’s been happening today
In some countries, like the UK, decarbonizing home heating and hot water is done by promoting heat pumps as a replacement for gas boilers. The reason why governments have encouraged using heat pumps is because they’re useful: they can convert one unit of electricity into two or more units of heat.
This capability is called coefficient of performance (COP). Now, while heat pumps can produce two or more units of heat, gas boilers have a COP of about 0.9. It’s even lower if they burn hydrogen, perhaps less than 0.5.
There’s a recent report by a government advisor known as the Hydrogen Champion recommended blending up to 20% hydrogen into the gas grid. However, it seems that the aim of this report is to encourage hydrogen production rather than reduce carbon emissions.
A possible alternative in the far future
So, looking from the things that we should put into consideration above, hydrogen for homes is not that great for now. Currently, it potentially increases carbon emissions due to its lower COP than methane; and the vast majority is produced from fossil fuels.
What about the longer term? According to some experts, we’re more likely to use hydrogen in transport and heavy industry than in houses.
Although, this doesn’t seem to stop UK gas network operators. They’ve stated that they’re transitioning the gas grid to hydrogen, with work already underway planning the upgrades to regional pipelines that will be required and for pilot projects with small groups of houses.
Boiler manufacturers are also promoting hydrogen-ready boilers that can be installed now in anticipation of 100% hydrogen supply.
However, transitioning the entire gas grid to hydrogen would be an enormous task. Experts believe that most likely, some hydrogen hubs develop in places with surplus renewable energy generation to produce green hydrogen.
Some other experts also still believe in hydrogen. For instance, Amit Kumar, a University of Alberta engineering professor said that a blend of hydrogen and natural gas could save as much as five per cent on carbon emissions without changing existing infrastructure.
Kumar also added that the transition to hydrogen is achievable without any modifications. The amount of hydrogen in the blended fuel, however, mustn’t exceed between 15% and 20%.
“You don’t need a major investment. You can use the existing infrastructure and slowly replace it to take on a higher percentage of hydrogen. It gives you time in a slow transition,” Kumar said.
So… no hydrogen for now?
Since hydrogen is quite risky, and we have no control over what sort of gas gets delivered through the pipes to your house, and we have to make sure that the switch is going to be safe—not to mention making sure that we don’t need to buy new household appliances—how do we switch to clean energy as eco-conscious people?
One, if we can afford it or are eligible for government support, is to insulate our home and install a heat pump. This will reduce household carbon emissions and save some money along the way.
Two, we can be more energy-efficient by installing insulation in windows, walls and lofts. This could reduce the average energy demand for space heating by as much as 75% if retrofitted to Passivhaus standard (an international benchmark for very low-energy construction).
Three, we can just go all-electric. According to experts, switching from gas to electric equipment can happen incrementally with existing infrastructure, and electrified buildings connect directly to an increasingly clean electricity grid, which supports decarbonization.
It’s true that with going all-electric, some homes would need new electrical panels or wiring, and utilities might need to upgrade distribution system equipment. However, these investments also support the ongoing transition to electric vehicles while boosting grid reliability.
The experts added that electrification an decarbonize our buildings today while delivering affordable, safe, reliable, and higher-quality services.
All in all, while hydrogen—if it’s green in production—could have an important role in the clean energy economy, some experts don’t recommend using hydrogen for homes. At least, not for now.
But what do you think? Should we switch to hydrogen? Should we go all-electric? Should we just install heat pumps? Or should we utilize more insulation? Tell us your thoughts.
Sources
https://techxplore.com/news/2023-04-methane-hydrogen-homes-bad-ideahere.html
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