Installer was invited by Worcester Bosch to see its 100% hydrogen prototype boiler in action, at the UK’s first Hydrogen Home. Here are the key things that installers need to know.
The Hydrogen Homes were opened on 15 July, which showcase how houses with appliances fuelled entirely by hydrogen would work.
The two semi-detached homes have been built in a partnership between gas distributors Northern Gas Networks (NGN) and Cadent, and the Government’s Department for Business, Energy and Industrial Strategy (BEIS).
Whilst the primary role of the Hydrogen Home is to support public awareness and engagement, it is being used for much more than that. Acting as a live citizen science project, the homes will deliver critical data and provide invaluable insight into how appliances can be used and adapted for the low carbon homes of tomorrow.
Worcester Bosch provided one of the 100% hydrogen ready boilers for the houses, which also feature hydrogen-burning hobs, cookers, fires, hydrogen gas meters, all manufactured in the UK, and a hydrogen BBQ from Australia.
When we first entered the house we were greeted with a kitchen to the left, where Worcester’s 100% hydrogen burning boiler is installed on the wall, providing hot water and heating to the home.
The boiler is based on Worcester’s Greenstar 8000 model, and without the hydrogen branding on the case, you would hardly be able to tell the difference.
“It’s not very entertaining to look at,” laughed Martyn Bridges, Director of Technical Communications and Product Management at Worcester Bosch, “and that’s why it’s such important technology.
“Behind the case, there are some really intelligent things going on that our Research and Design team has worked very hard on to burn hydrogen effectively, but from a consumer’s point of view, it’s just like any boiler.
“It will be the same boiler sizes, and heating-system-wise, everything remains the same. The radiators are identical to those connected to gas central heating systems in our homes today, the gas pipe is the same size at 22mm, and the same heating controls. We may need to change any mild steel pipework to copper, but that’s still to be tested and most houses are copper anyway. So, for heating engineers, the installation process is no different.”
The hydrogen switchover
The UK Government has published its Hydrogen Strategy which aims to meet its ambition for 5GW of low carbon hydrogen production capacity by 2030.
Government analysis suggests that 20-35% of the UK’s energy consumption by 2050 could be hydrogen-based, which would be critical to meet net zero emissions by 2050, and cut emissions by 78% by 2035.
The idea is to set a date where only hydrogen-ready boilers would be allowed to be sold in the UK. These boilers would be ready to run out of the box on natural gas, but if (and when) the time came for the gas supply to change to hydrogen, an installer would be able to change the boiler to run on 100% hydrogen using a conversion kit, offering a no regrets option, with minimal disruption to people’s lives.
“The kit would consist of three parts for conversion,” Martyn explained. “We’re looking at the burner, gas valve orifice and code plug. These are cost-effective components and would take installers around half an hour to switch over. We’d imagine installers would have to do a training course and add a potential hydrogen model to their Gas Safe Register ticket to prove competence, like they do for LPG.
“Boiler-wise, the hydraulics are the same, the gas valve is the same but the burner is different because hydrogen has a higher calorific value than methane gas. It’s just a different design rather than being more expensive to make. The mixing of air and gas is slightly different as well which is why some components are unique for hydrogen.
“Emissions-wise there’s no carbon monoxide which is a big plus, the boiler just produces water vapour and low-level NOx. We’d actually consider it ultra-low, lower than the equivalent natural gas, roughly half, which is another benefit.”
Hydrogen appliances
The hydrogen-burning appliances in the houses are early prototypes, and as a result, are still being developed and refined, but they look very similar to their natural gas equivalents.
Hydrogen is presently odourless and burns clean, with the flames getting brighter as they burn. The flames burn straighter as hydrogen is a lighter gas and LED lights have been built in to indicate to the user that the hob is on.
There is also more water vapour produced as hydrogen produces H2O when it’s burned, so the oven steamed up quicker than you would usually expect. There is no need to install extra ventilation measures in the house however, as that extra level is insignificant compared to the water given off during the cooking process from the food itself.
Safety-wise, Hydrogen eliminates the risk of deadly carbon monoxide poisoning, so there’s no need for a carbon monoxide alarm in the home. The HSE has also mandated that hydrogen will be odorised with the same smell as natural gas, so it can be easily detected.
Other than that, in terms of performance, there isn’t much difference at all.
The future
There are still plenty of challenges to solve, but seeing hydrogen appliances work in real life scenarios is impressive and demonstrates what a hydrogen future could look like for the public and installers.
“It’s easy to see why the government and the industry are excited about this concept,” Martyn commented. “The boilers are the same and people are used to the technology, the workforce is already there with the Gas Safe Registered engineers and it won’t hike costs for the end user.
“Four of the biggest UK boiler manufacturers, including Worcester Bosch, have signed a pledge to agree that a hydrogen-ready boiler will cost no more than its natural gas equivalent, and a similar pledge has been made to the European Commission that the components needed for conversion to 100% Hydrogen would be no more than around 10% of the boiler price.
“We believe that it will take a mix of technologies to achieve net zero and while heat pumps are a fantastic solution for new builds, these hydrogen boilers are a very straightforward option for engineers and low disruption for existing buildings that are already on the gas grid.
“With the Hydrogen Homes, we’ve demonstrated that the technology can work, and we know that the energy providers are keen to start producing hydrogen to use in the gas grid. It’s a very exciting time and a big step forward to achieving a hydrogen economy in the UK that can reduce carbon emissions, using the technology and skill set that heating engineers have been using for decades.”
