September 2021, Vol. 236, No. 9

Features

Making Hydrogen Work for UK’s Commercial Buildings

By Nicholas Newman, Contributing Editor  

The provision of heat, hot water and heat for cooking in homes and businesses accounts for more than 35% of the U.K.’s energy consumption, according to BEIS. Today, 23 million homes are connected to the gas network, around 90% have boilers for space and water heating and about half have gas hobs and fires.   

While domestic heat makes up more than half of the U.K. heat demand, commercial and industrial properties’ space heating, hot water and heat for cooking account for more than a quarter. Therefore, any conversion from natural gas to hydrogen in the national and local pipeline grids must cater to larger-scale commercial and industrial heating.   

Gas pipeline beneath thick undergrowth on the outskirts of a U.K. town.
Gas pipeline beneath thick undergrowth on the outskirts of a U.K. town.

In keeping with Europe, the government has shown interest in decarbonizing heating provisions by converting the U.K.’s natural gas grid to hydrogen. The Prime Minister’s 10-point plan envisages that any conversion of the network is likely to start by blending natural gas with up to 20% hydrogen.  

This feature looks at the challenges, technologies, benefits and prospects that commercial building owners and operators will face in the transition from natural gas to hydrogen.  

The Challenges  

The U.K.’s natural gas pipeline network comprises the 6,000-mile (10,000-km) national grid transmission network and more than 15,000 miles (24,000 km) of local distribution networks. National Grid is currently conducting research into the impact that injecting various levels of hydrogen, starting at 2%, then 20% and eventually 100%, could have on its networks. Meanwhile, in the case of the local gas distribution networks, which have been replaced mostly by plastic pipelines, embrittlement should pose less of problem.  

Surprisingly, current appliances and infrastructure do not present a major obstacle to using hydrogen for heating.   

“Existing gas appliances can use 10% blends with no issue at all; many modern condensing gas boilers can work with up to 20% blend with new certification; future 100% hydrogen ready boilers could be retrofitted at low cost,” according to Robert Whitney of the IEng MIET-IET Built Environment Policy Panel. “For 100% hydrogen there may need to be some upgrades to gas mains from old iron mains to PE pipes and re-piping of gas runs in buildings.”   

The real obstacle is producing sufficient hydrogen to meet potential demand and its cost. At present, there is insufficient production capacity to meet an 80/20 energy mix, let alone a future where hydrogen totally replaces natural gas. Currently, at least 90% of world hydrogen production is gray hydrogen, produced by the steam-methane reforming process powered by fossil fuels, a process that emits considerable amounts of carbon.  

To decarbonize heating with hydrogen would require a significant increase in green hydrogen production using electrolysis powered by renewables or nuclear. Yet, the International Renewable Energy Agency (IRENA) estimates that, currently, green hydrogen costs two to three times that of gray hydrogen. To make hydrogen a plausible energy source of the future will require investment in many gigawatts plus scale electrolyzers to gain economies of scale and necessary cost reductions.   

For building owners and operators, hydrogen theoretically can be used as an energy source in the same way as natural gas (i.e., as a boiler for central heating and water or as an energy carrier in a combined heat and power plant, providing additional services including power generation).  

A hydrogen gas boiler operates in a similar way to that of a conventional gas boiler. The main design difference is that it uses either natural gas or pure hydrogen to provide heat and hot water.   

Technology Issues 

However, according to boilerguide.co.uk, a few internal components are different, including the flame detector and burner. If the gas network was fully converted to a 100% hydrogen supply, a few key components would need to be replaced by Gas Safe-registered engineers. The requisite technology is already in the early stages of technological development and deployment.  

In practice, it is not yet possible to buy commercial boilers that make 100% use of hydrogen. However, specialist technology providers including Worcester Bosch, Viessmann and Baxi are working to create market-ready products. Enertek has developed warm air and radiant heaters that use hydrogen variants, and these heaters are being certified for commercial use.  

80% Mix  

Last year, Keele University campus was supplied with an 80/20 mix through its natural gas network. The start of a year-long trial in 2021 heralded test of an 80/20 hydrogen mix supply to around 650 households, a church, a primary school, and several businesses in the village of Winlaton, near Gateshead in the northeast of England.   

The HyDeploy North East plan involves local gas distributor Northern Gas Networks assisted by Cadent.   

Tim Harwood of Northern Gas Networks said, “By just taking part in this and not even really noticing a difference, they are actually making a big difference to decarbonization; in the future, they can proudly say that they were the first people to be part of this trial that set us on our way.”   

So far, the trials in the U.K. and Europe indicate that an 80/20 mix of gas and hydrogen make little or no difference to heating in either homes or businesses.  

On-site hydrogen fuel cells could become a viable alternative to power purchased from the electricity grid. For building managers of commercial properties, such as offices, hotels, small businesses and public-sector buildings like hospitals, this alternative could prove a viable on-site solution for cutting power bills and carbon emissions.  

In practice, this technology is still in the early stages of development and deployment, although a few examples are to be found in the U.K. and Europe. Obtaining accurate operational commercial costing has yet to be fully detailed for the building owners and operators so that they might consider all the benefits.  

An exception is the 400-room and suites Radisson Blu hotel in Frankfurt, Germany, which, since 2017, has used a 400-kilowatt fuel cell, supplied by Edinburgh-based Fuel Cell Energy Solutions (FCES) through   

German energy utility E.ON. E.ON supplies 3 gigawatt hours of electricity and 2 gigawatt hours of heat each year while reducing carbon dioxide emissions by about 600 tons a year, which is equal to the emissions from 50,000 cars driving 310 miles (100 km). One estimate puts the resultant energy cost savings, because of the fuel cell installation, at about $991,000 (€750,000 per year).  

Since 2012, Lee Kum Kee Group’s 38-story Walkie Talkie Tower in London, also known as 20 Fenchurch St., has relied on a $5.66 million (£4 million) hydrogen fuel cell to supply underfloor heating, cooling and electricity. Provided by FCES, the fuel cell generates 300 kilowatts of low-carbon electricity and has reduced the building’s carbon dioxide emissions by at least 270 tons per annum.  

Benefits of Hydrogen  

A 20% hydrogen natural gas blend only equates to about 7% decarbonization. Nonetheless, there remain advantages to this approach for building owners and operators. According to Whitney, “there will be a rapid roll out and lower cost and disruption to buildings than heat pump retrofits.”   

One thing is clear, governments across Europe and in the U.K. recognize the potential for decarbonizing household, commercial and industrial heating by diluting the grid supply with hydrogen. A blend of 80/20 gas and hydrogen is attainable, avoids stranding infrastructure assets worth an estimated $42.47 billion (£30 billion) and minimizes disruption and costs for business and industry.   

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