Of all the potential uses of clean hydrogen, the heating of buildings is by far the most controversial.
At least 32 independent studies have slammed the use of H2 for heating, pointing out that burning green hydrogen in boilers will require five to six times more renewable energy than highly efficient heat pumps to produce the same amount of heat.
Most campaigners for hydrogen heating — mainly gas distributors and boiler makers — have resorted to spreading lies about heat pumps, such as that they don’t work in old buildings or can't be used in apartment buildings, to try to make their case.
Trade body Hydrogen Europe has taken a different tack in an eight-page “brochure” entitled Use of Hydrogen in Buildings released yesterday that aims to answer one leading question that takes up the entire second page: “Why should hydrogen be considered an important element in meeting the decarbonisation challenges of the heating market?”
There are four reasons, according to Hydrogen Europe:
1) Hydrogen can alleviate the electricity grid expansion requirements;
2) Hydrogen facilitates the storage of renewable energy to account for seasonality, securing supply for the entire heating sector;
3) Hydrogen allows the transportation of renewable energy from generation to consumption centres to account for geographical unbalances; and
4) Hydrogen enables imports of cheaper renewable energy from countries with large renewable resources, lowering costs and boosting system efficiency.
1) Grid expansion
“For a heat pump to cover large or entire building heating needs, grid reinforcements must happen much faster at distribution and transmission levels. Especially during cold waves, when electric heat pumps are less efficient, electricity demand will peak, likely constraining the distribution grids,” says the brochure.
“H2-power devices such as fuel cells, boilers, and integrated hybrid heat pumps would help alleviate grid expansion and constraints, lowering costs and increasing the pace of decarbonisation of the sector.”
It adds: “In the EU-27, if 91 million additional heat pumps are installed by 2050, the grid would have to handle a peak load of 292GW only from heat pumps. This represents about 65% of the total average peak load of the EU-27 in 2018.”
A counter-argument is that power grids need to be upgraded anyway to meet the increasing demand for electric vehicles, so the extra electricity demand for heating can be met at the same time. But of course, European power networks are not being upgraded fast enough to meet the coming demand and the costs of doing so would be high.
According to a report from electricity industry trade body Eurelectric last year, between €375bn ($398bn) and €425bn will be needed to be invested in Europe's distribution grids by the end of the decade — not including transmission lines — to ensure they can handle increasing volumes of variable renewable energy and green hydrogen production, as well as the expected electrification of heating and transport.
But the first academic paper to model green hydrogen usage on an hour-by-hour basis in a carbon-neutral energy system, published last month, concluded that “hydrogen cannot be considered a large-scale solution for heating and transport” due to “high societal costs and practicality issues”.
Hydrogen has long been touted as an essential energy storage medium, able to store excess solar power in summer for use in winter when the amount of sunshine inevitably declines and energy demand rises to heat cold homes.
Storing energy in the form of hydrogen “can store renewable energy and avoid further adding to the already existing imbalance between electricity consumption in winter and summer”, the brochure says.
Hydrogen Europe compares heat demand in France in 2021 with renewable electricity output, pointing out that the amount of available green power remained relatively stable throughout the year, but natural gas consumption obviously increased considerably in winter.
“A ‘one-size-fits-all’ approach will not work,” the brochure states. “Countries have different climates and different heating challenges. Hydrogen works well in very cold climate and poorly insulated buildings. It can be easily adopted by adapting existing gas infrastructure. At distribution level, pipelines do not need to be retrofitted, with investments only needed for adapting boilers and other appliances.”
Plenty of people would disagree with these assumptions.
For safety reasons, the installation of excess flow valves in the home are recommended, along with air vents above boilers to avoid a dangerous accumulation of H2 in the event of a leak.
There are also concerns that hydrogen molecules, which are far smaller than natural-gas molecules, could leak out from joints and valves — and H2 is not only explosive, but it is also an indirect greenhouse gas.
Gas compressors and pumps would also need to be replaced, while three times more energy would be required to pump pure hydrogen around the network compared to gas, due to the lower volumetric energy density.
Hydrogen also causes embrittlement of iron-based pipes, which make up a third of the UK’s local gas pipelines, although these are all due to be replaced by 2032, according to the UK Energy Networks Association.
Gas cookers and ovens would also have to be replaced if the natural-gas system moves over to 100% hydrogen, and these should ideally be electric as open hydrogen flames release high amounts of nitrous oxide, a very powerful greenhouse gas (something that can be captured and removed in the enclosed space of a hydrogen boiler in a similar way to catalytic converters in cars).
The notion that “hydrogen works well in very cold climate and poorly insulated buildings” is a big assumption, not least because H2 is used virtually nowhere for heating today.
It also appears to be a nod to the factually incorrect trope that heat pumps do not work in poorly insulated buildings.
And, of course, the biggest users of heat pumps in Europe are Scandinavian countries, which get colder than most in winter.
3) Energy transportation to consumption centres
“Unfortunately, not all regions in Europe can easily access cost competitive renewable electricity,” the brochure explains.
“Germany is struggling to transport excess onshore wind [power] from the north to the south. Landlock[ed] countries, such as the Czech Republic and Slovakia have limited renewable resources and limited access to the large resources in the north seas. A large degree of electrification of the heating sector would only exacerbate this problem.
“In 2019, wind onshore electricity generation in the North was significantly higher than in the South of Germany, and about 5,100 GWh had to be curtailed.”
This is slightly disingenuous, as Germany is planning to build three new North-South high-voltage power lines to alleviate this problem.
In response to Hydrogen Europe on this point, independent hydrogen analyst Gniewomir Flis wrote on Twitter yesterday: “What do you think Germany should do here? a) Turn 5TWh of curtailed electricity into hydrogen and generate 3TWh of household heat, or b) Build an electric transmission line and use heat pumps to leverage 5TWh electricity into 15TWh of heat?”
A hydrogen transmission line would, however, almost certainly be cheaper and easier to build than a new high-voltage power line.
4) Hydrogen enables cheaper renewable energy to be imported
The brochure says that wind and solar resources are higher in the Middle East than Europe, and can therefore produce cheaper green power. This can then be imported in the form of hydrogen, thus “lowering costs and boosting system efficiency”.
But when taking into account the costs of converting Middle Eastern power to green hydrogen, then compressing and storing that H2 and transporting it to Europe, it may no longer be a cheaper form of energy.
“Hydrogen can ease the race to modernise buildings, alleviating the craftsman sector bottlenecks, reducing the burden on individuals to bear the costs of full [domestic heating system] renovations, and accelerating decarbonisation,” the brochure concludes.