New York Times: A Next Generation Approach to Heating and Cooling Buildings

Tourists strolling along the banks of the River Thames in the heart of London will soon have reason to be grateful for a busy construction site on their path.

As it nears its scheduled completion over the next few years, the Bankside Yards project of shops, offices and 600 apartments will open up new public spaces and make it easier to walk between attractions such as Tate Modern and the Royal Festival Hall.

“It’s going to be a missing link in this cultural sector along the river, turning a huge, impenetrable urban block into part of that cultural sequence of spaces,” said Daniel Moore, an architect and the technical director of the project for PLP Architecture.

But the 5.5-acre development, expected to cost 2.5 billion British pounds (about $3.3 billion), has a greater significance than speeding up a scenic pathway.

Hidden inside the eight-building complex is a pioneering energy system that poses important questions about the pace of decarbonisation in the United Kingdom and elsewhere.

Bankside Yards is using a “fifth-generation” combined heating and cooling network that can balance energy within each building and then between buildings by collecting unwanted heat, say from a refrigerator in a restaurant or a piece of office equipment that needs to be cooled, and carrying that heat to somewhere that needs hot water or domestic heating.

Electric-powered heat pumps on building rooftops and in each apartment or commercial space then adjust the temperature of the water by withdrawing or injecting heat into the pipes to provide the heating, cooling and hot water needed in each place.

“One apartment might be rejecting heat because they’ve got air conditioning on, but someone else is taking a shower and needs hot water,” Mr. Moore said.

Marco Wirtz, a German engineer and expert on fifth-generation systems, said that “by connecting buildings with many different use types, the Bankside Yards project significantly enhances the efficiency of its network, making it one of the largest and most innovative implementations of fifth-generation technology in the world.”

Not only can the energy system at Bankside Yards reduce the amount of energy needed to heat, cool and provide hot water to the complex, it also operates without fossil fuels, providing an important tool in the effort to reach net zero carbon emissions.

The most pressing question, according to Dr. Jan Rosenow, the European program director of the Regulatory Assistance Project, an energy policy nongovernmental organisation, is why similar systems are not being rolled out at speed and scale everywhere, given that heating homes alone produces almost a fifth of all greenhouse gases in the United Kingdom.

Dr. Rosenow said the ability to slash the energy needs of Bankside Yards and fuel them entirely by renewable electricity again shows that we have solutions to reduce emissions but are not applying them at the pace needed.

“It’s no longer a technology problem; I think the social and political aspects, cultural aspects, are actually more important when it comes to how fast you can move,” he said.

Nicholas Gray, the sales and marketing director of the project’s developer Native Land, said one of those factors, social attitudes, might be shifting because cleaner buildings “are what office tenants and residential buyers are increasingly looking for.”

The first building in the complex, a 19-story office tower called Arbor, was completed in 2023 and is already more than 75 percent rented or under offer by tenants, including the environmental consultancy the Carbon Trust.

The fifth-generation network is the latest version of district heating, an approach commercially pioneered in the United States in the 1870s, in which buildings were heated through a shared network of pipes rather than having their own boilers or stoves.

Early versions used a central furnace to distribute steam at up to 390 degrees Fahrenheit, later moving to extremely hot water before successive generations of district heating lowered the temperatures to reduce the amount of heat lost from the pipes.

“Those high temperatures are why the corridors and lobbies of a lot of existing building are always overheating — it is typical to lose 20 percent to 40 percent of the energy that you’re producing,” said Giovanni Festa, a project director for Sweco, a Swedish-based engineering consultancy, who oversaw the design of the energy system at Bankside Yards.

A fifth-generation network is also known as an ambient loop because the water in the pipes is not far above the normal outside temperature — at Bankside Yards the water is below 77 degrees Fahrenheit. The complex’s managers have negotiated supply deals with renewable electricity providers for the apartment heat pumps, which are the size of small refrigerators and are hidden in soundproofed cupboards.

Mr. Festa said the energy requirements of the Arbor building had been slashed by high-quality window glazing and design so that it used 30 percent less energy than current best practice standards.

After Bankside Yards reaches its scheduled completion in 2029, facility managers will review performance data to improve the system’s efficiency, and weather forecasts will be used to fine-tune performance further.

“I think we’re at least two or three years ahead of our competitors because other buildings being completed now are still using gas-fired systems,” Mr. Festa said.

Another large ambient loop system is being built at the 1,600-apartment Silvertown development in East London but there are still relatively few such projects almost a decade after the term fifth generation was first coined by European Union researchers.

A report on district heating systems from Cardiff University’s School of Engineering identified 74 fifth-generation networks in Germany, 16 in Switzerland and smaller numbers elsewhere, including three in China.

One of the largest projects in the United States using an ambient loop system and heat pumps is the Whisper Valley residential complex in Austin, Texas, which eventually plans to have 7,500 homes.

The British government estimates that around 20 percent of the nation’s buildings could be served by district heating, but heating experts said there has been little government effort to promote the latest solutions in privately owned new construction and retrofits, or in government-owned buildings.

Jamie Osborn, a spokesman for the MCS Foundation, a British charity promoting decarbonization, said the obstacles to faster deployment include a lack of planning reform and poor public awareness.

While costs will vary between each project, Mr. Festa said that installing a fifth-generation system might cost slightly more than an older gas-based system but any extra investment would be recouped by energy savings. And the system’s zero carbon emissions mean it would not need to be retrofitted as minimum carbon standards are lowered.

According to the European Heat Pump Association, 60,000 heat pumps were sold in the United Kingdom in 2023, compared to 720,000 in France, which has only a slightly larger population, helping France to cut its heating emissions more than 10 times faster.

The association’s former secretary general, Thomas Nowak, now an executive at Qvantum, a Swedish-based firm promoting ambient loops, said the system “belongs at the center of every city” but it was hampered by a lack of knowledge among policymakers as well as ordinary consumers.

The sense that heating is an individual, rather than collective, task “is not unique to the U.K.,” Nowak said, noting that the German government struggled last year when trying to impose heating reforms.

“It probably goes right back to when you wanted to decide who lights a fire in your cave,” he said. “Maybe you did everything by yourself in the past but now we have the opportunity to share much better solutions in a way that the whole integrated system is more efficient for everybody.”