Heat Vision

Article by Pippa Corbett AMIChemE

Pippa Corbett takes a closer look at the potential of heat networks, recent market transformations, and a sustainable chemical engineering career pathway

Quick read

  • Heat Network Zones Implementation: Starting in 2025, designated heat network zones will facilitate the cost-effective deployment of heat networks in England, promoting greener heating solutions for communities
  • Decarbonisation Role: Heat networks are vital for decarbonising the heating sector, which accounts for nearly a third of the UK’s carbon emissions, and can significantly contribute to achieving net-zero targets
  • Opportunities for Engineers: The growing heat network sector presents substantial career opportunities for chemical engineers, allowing them to engage in sustainable projects, innovative heat recovery solutions, and interdisciplinary collaboration

Why is 2025 an important year for heat networks in England?

In 2025, the implementation of heat network zones will begin, marking a major milestone in the development of heat networks across England. The new heat network zoning framework is set to transform how heat networks are deployed in towns and cities across England by designating geographic areas where heat networks are expected to be the most cost-effective solution for decarbonising heating systems. This will empower local communities to accelerate the rollout of greener, more affordable heat to homes and businesses.

Heat network zoning will likely require certain types of buildings and low-carbon heat sources to connect to the network within a specified timeframe (with some exemptions). By focusing on the largest heat consumers within a zone, a critical mass can be achieved, providing the investment certainty needed to expand these networks. While much of the framework has been outlined by the UK government, some details are still pending final legislation (https://bit.ly/3BL3uSo).

Why should chemical engineers care about heat networks?

The heating sector is a major contributor to the UK’s carbon emissions, which must be addressed if we are to meet national climate targets. This sector accounts for nearly a third of the UK’s annual carbon emissions, including space heating, cooling, hot water, industrial processes, and cooking. The government’s Clean Growth – Transforming Heating report stated that “heating is arguably the most difficult of the major energy consuming sectors of the economy to decarbonise”. Without a revolution in heating, the UK will struggle to meet its climate goals. As natural problem solvers, chemical engineers have a crucial role to play in developing solutions for decarbonising the heating sector, and heat networks represent a viable option to tackle this challenge.

Secondly, the district heating sector presents a sustainable career path for chemical engineers that may not be immediately obvious. Traditionally, many chemical engineers, if they are interested in energy, pursue a career in less sustainable areas. During my job search, I found that most roles in the sustainable energy sector were geared towards electrical engineers, focusing on power generation and renewable technologies. It was then that I discovered the district heating sector. A career as a district heating engineer offered me the opportunity to work on meaningful, sustainable projects while applying the skills and knowledge gained from my chemical engineering education. My day-to-day tasks include everything from sizing heat supply equipment to conducting hydraulic and optimised energy modelling for network pipework, where I actively utilise fundamental chemical engineering principles from thermodynamics to fluid mechanics.

What is a heat network?

Gov.uk

A heat network consists of insulated underground pipes that transport hot water from centralised energy sources to multiple consumers, such as public buildings, shops, offices, hospitals, universities, and homes. These networks can supply entire cities or clusters of buildings. Rather than each building relying on its own heating system, a heat network efficiently distributes heat across multiple locations at once. Typically, most modern heat networks have been powered by commercial gas boilers often in combination with gas-fuelled Combined Heat and Power (CHP) units. However, heat networks are increasingly shifting away from these traditional gas-fired systems to electrically powered solutions, such as heat pumps (water, ground or air) and electric boilers. Additionally, heat networks are increasingly incorporating renewable heat sources, like biomass, and waste heat recovery from processes such as waste incineration, data centres, and other industrial activities.

Four reasons why heat networks are beneficial

  • Utilisation of low-carbon heat: Heat networks can tap into local heat sources that would otherwise go to waste, making them a low-cost and low-carbon option to decarbonise heat.
  • Operational efficiency: Heat networks serve buildings with varying heat demand patterns, eliminating the need for oversized heating systems. They also offer flexibility in adjusting the temperature and volume of heat delivered.
  • Energy security and resilience: In volatile energy markets, heat networks offer stability. By using diverse heat generation sources and offering long-term contracts with price guarantees, they provide a reliable, secure heating solution that is less affected by the fluctuations of fossil fuel prices.
  • Accelerating the route to net zero: Heat networks decarbonise the heating systems of multiple buildings simultaneously, providing significant commercial and technical benefits through economies of scale. This approach not only supports the UK’s climate change target of achieving net zero emissions by 2050 but also enhances the scale and pace of the transition to a more sustainable energy future.

What key engineering challenges are you helping to address?

Insulated heat network pipework

Significant challenges remain in accelerating the deployment of these low-carbon energy networks. In 2023, heat networks supplied approximately 2–3% of the UK’s heating needs. To achieve net zero by 2050, this must increase to at least 18% – countries like Denmark and Sweden are already at 85% and 65%, respectively.

The installation of heat network pipework within congested urban infrastructure requires close collaboration with civil, mechanical, and utility engineers to navigate complexities in utility coordination. This interdisciplinary approach fosters shared expertise across engineering disciplines.

Achieving a balanced heat supply and demand is critical. Reusing waste heat from sources like data centres, sewage treatment plants, and Energy from Waste (EfW) facilities is an exciting development area. For instance, I recently assessed the feasibility of capturing waste heat from High-Voltage Direct Current (HVDC) converter stations. Innovative heat recovery methods not only reduce costs but also significantly cut emissions, aiding the UK in reaching its net-zero target.

Expanding existing networks to incorporate additional consumers requires strategic pipework design that anticipates future growth while minimising thermal losses that occur from the pipes to the surrounding environment. Addressing these engineering challenges is essential for optimising cost efficiency and ensuring scalability in the heat network sector.

What key opportunities exist for chemical engineers in the future?

Pippa chairing a conference discussion on ‘The Decarbonisation Challenge’

Developing heat network zones across the country will require an investment of tens to hundreds of billions of pounds and has the potential to create thousands of jobs, driving a low-carbon heating revolution. This rapidly growing sector presents an exciting opportunity, especially for early-career chemical engineers, as the small size of the district heating industry allows for quick project ownership and greater autonomy. To maximise the potential of zoning regulations in England, it’s crucial to attract passionate individuals with the skills needed to design and implement effective heat networks, addressing the current skills gap in the industry.

Additionally, there are opportunities to engage and gain experience throughout the entire project life cycle, beginning at the feasibility stage, where the technical and economic viability of a district heating network is assessed, then moving on to subsequent phases, including detailed design, commercialisation, and construction. While certain aspects of the process are technically intensive, chemical engineers can also apply their competencies in areas like economic analysis, management of projects, and prioritising health and safety throughout.

With the incoming low-carbon heating revolution, chemical engineers have a pivotal role to play in shaping a sustainable future, driving innovation, and enhancing energy resilience through the implementation of efficient heat networks.

And, as we approach 2025, I am excited to be working on projects exploring capturing waste heat, part of the transformative journey that will accelerate the deployment of heat networks across England. An intriguing engineering challenge – turning what would otherwise be wasted energy into something beneficial – it will play a crucial role in lowering the carbon content and cost of heat for consumers. I am also eager to see how policy evolves and drives the exponential growth of heat networks, allowing them to transform energy systems and help us reach critical milestones in the fight against climate change.

Article by Pippa Corbett AMIChemE

Senior consultant in the sustainability advisory – energy transition team at Arcadis, specialising in the development and decarbonisation of heat networks across the UK

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