What is a heat network?
Heat networks (or district heating networks) distribute heat generated in a centralised location via a network of insulated, water filled pipes to domestic and commercial buildings for space heating and hot water. One advantage of heat networks is that they generate heat centrally, rather than in each building which is much more efficient.
Heat networks can be supplied with heat from a variety of sources, including zero carbon sources and heat from processes that would otherwise be wasted. Heat is transferred into individual buildings of any size via a heat exchanger at which point the heat consumption is metered.
Heat networks are an extremely common technology with a long history, particularly in continental Europe. Vattenfall operates city-scale heat networks in Amsterdam, Rotterdam, Berlin and Uppsala as well as many other smaller cities.
What's so good about district heating?
- Low carbon: heat networks use renewable and low-carbon energy sources, such as heat pumps, biomass, geothermal energy, and waste heat recovery.
- Efficient: heat networks are more efficient than individual heating systems because of their economies of scale. Centralised generation and distribution of heat is more efficient as it reduces the need for as much total heat generation capacity, reduces waste and optimises energy consumption.
- Flexibility: heat networks can use a variety of sources of heat, allowing for flexibility in the choice of fuel or heat generation methods. This flexibility ensures resilience in the face of changing energy markets and allows for the integration of renewable energy sources as they become more cost-effective and available.
- Cost savings: heat networks can provide cost savings to consumers due to their economies of scale and use of low-cost energy sources. By aggregating demand and optimizing heat generation and distribution, the overall cost of heating can be reduced compared to individual heating systems.
- Reliability and resilience: improved reliability compared to decentralised heating systems. By providing redundancy and backup options, such as multiple heat sources and distribution routes, the networks can ensure a stable and continuous supply of heat, even in case of individual component failures or disruptions.
- Simple operation: heat is metered at the connection point which is owned and operated by the network operator. Consumers don’t need to worry about the maintenance of their own heat source, this is taken care of by the heat network operator.
- Improved air quality and public health: Replacing individual fossil fuel-based heating systems with low carbon heat networks reduces the emissions of pollutants, such as particulate matter, nitrogen oxides, and sulfur dioxide. This leads to improved air quality, which has positive impacts on public health, reducing respiratory and cardiovascular diseases.
- Scalability and future-proofing: heat networks are scalable and can be expanded to accommodate increasing heat demand or incorporate new developments. This scalability makes them suitable for urban areas, industrial parks, and large-scale projects, providing a future-proof heating solution that can adapt to changing needs and technology advancements.
- Local economic resilience: a locally run heat network leads to more economic activity in the region and less money leaving it to purchase energy from the international market. It gives cities power to govern and plan energy security and to tackle issues such as fuel poverty and ensure a just transition.
- Local skills: heat networks are large scale, long-term energy infrastructure projects with a complex supply chain and a requirement for a huge range of different skills. Vattenfall’s investment in heat networks in Bristol will create numerous jobs over a multi-decade timeframe and work is already starting to upskill the workforce of the future.
Why do we need heat networks?
Nationally, around 2% of heating demand is supplied by heat networks and the UK Climate Change Committee has stated that this figure will need to rise to 18% in order for the UK to hit net zero by 2050.
There are a variety of reasons that a heat network might be the best solution for a given building, rather than a heat pump. These include spatial constraints, lack of electricity capacity and building heating systems being too high.
District heating networks can have far reaching benefits including infrastucture, social responsibility, supporting governement targets, and keeping energy bills down.