Exploring the Future of Energy: Fifth-Generation District Heating Networks and Ground Source Heat Pumps
As the world grapples with the challenges of climate change and seeks to reduce carbon emissions, innovative solutions in the energy sector have become essential.
Heating buildings is responsible for 40% of EU emissions and 36% of final energy use, according to EU statistics.
One solution gaining traction is Fifth-Generation District Heat Networks (5GDHN). Although the definition of these networks is still a matter of debate amongst the industry, these advanced systems of networked heat pumps are revolutionising the way we produce, distribute, and use heat, offering a path to a more sustainable and energy-efficient future.
As Genius Energy Lab’s Chief Technical Officer, Chris Davidson, explains, GEL has been at the forefront of 5th generation network design for nearly a decade, specifically pushing innovation in this area via advanced modelling and hydraulic simulation.
“Genius Energy Lab’s innovations such as the removal of the need for central pumping and bidirectional header flow are firmly established as part of our expertise. These developments allow broader delivery of networks by reducing cost and allowing a wide variety of business models to be applied.”
Chris Davidson, CTO of Genius Energy Lab
Let’s explore how ground source heat pump technology and district heating networks can work hand in hand.
Understanding District Heating Networks: What and Why?
Before delving into the concept of a fifth-generation heat network, let's first understand the concept of district heating networks.
The fundamental idea is simple: reusing / recycling surplus energy that otherwise would be wasted. Networked district heating involves a method of centrally producing and distributing heat for space heating, hot water, and cooling to multiple buildings within a localised area. It's a more efficient alternative to individual building heating systems, as it centralises heat generation, reducing waste and emissions.
According to a scenario analysis within Heat Roadmap Europe of the future EU heat demand, the greenhouse gas reduction ambitions of 80% by 2050 compared to 1990 levels can be achieved via the large-scale integration of district heating and cooling networks.
Given the challenges of energy security in Europe in recent times, energy operators, and both national and local governments are looking for ways to decarbonise their district heating networks: and large-scale heat pumps are in their sights.
Jan Rosenow, director of European programmes at the Regulatory Assistance Project (RAP), a non-profit group dedicated to accelerating the transition to clean energy pointed to this change:
“In Denmark, Finland, and Sweden, we have seen an increasing number of those being used to supply heat for district heating. So there is a shift happening. And where we’re going next is clearly in favour of renewable electricity and heat pumps.”
Networked heat pumps keep energy costs down, and have lower installation costs than traditional Combined Heat and Power district networks - with communal ambient temperature ground loops with individual heat pumps being the most economic solution of all: Fifth-Generation Heat Networks.
To find out more about networked heat pumps, get in touch.
The Evolution: Fifth-Generation Heat Networks
Fifth-Generation Heat Networks represent a significant leap in the evolution of district heating technology. They go beyond the traditional district heating systems by integrating cutting-edge innovations, including renewable energy sources, smart technology, and enhanced efficiency.
In 4th generation heat networks, the heat from the energy centre is delivered to the customer via a 'Heat Interface Unit' or HIU that contains heat exchanger(s) and metering and billing facilities.
In 5th generation networks the energy centre is often not required and heat is delivered via networked heat pumps located close to the point of use. These could be in plant rooms within individual buildings or distributed further down to an individual dwelling or room in commercial buildings. In 4th generation heating grids, the heat from the grid is delivered to the customer via a ‘substation’ that contains one or more heat exchangers.
The important consequence is that the grid transports thermal energy, but it does not need to deliver the required temperature. Every building gets exactly what it needs, nothing more. Since these heat pumps are bidirectional, the energy stations can deliver both heating and cooling: to do this with conventional technology would require a second cooling network at a significantly increased cost. Further, the pipes in 5th generation heat networks are often uninsulated, allowing further significant installation cost reductions.
The grid and the heat pumps can deliver the service at a very high Seasonal Coefficient of Performance (SCOP), which reduces the electricity consumption to a level where it can ultimately be provided from sustainable sources.
According to the IEA, the integration of renewable energy sources, such as solar, wind and geothermal, can increase the share of renewable energy in district heating to as much as 50% or more.
Europe currently leads renewables integration in district heating, with around 25% of its district heat supplies produced from renewable sources:
In Helsinki, Finland, the city's 5GDHN relies on renewable energy sources for over 90% of its heat production, significantly reducing carbon emissions (Source: Helsinki Energy)
Stockholm, Sweden, has been using ground source heat pumps and biomass in its district heating system, reducing carbon emissions by approximately 50% (Source: Stockholm Exergi)
While the goals are energy efficiency and lower project costs - highly efficient district heating systems can reduce operational costs by up to 40%, increasing cost-effectiveness for both providers and consumers (IEA) - the result is also the decarbonisation of the energy supply.
A fifth-generation heat network alongside GSHP, is therefore compliant with many companies’ and districts’ decarbonisation ambitions - with the resultant systems producing fewer carbon emissions and delivering improved air quality.
Dive into our set of services helping to design innovative GSHP systems for district heat networks.
District Heating Networks: ramping up their use
In 2022 district heat production remained relatively similar to the previous year, meeting around 9% of the global final heating need in buildings and industry, according to the IEA.
Fossil fuels still dominate district network supplies globally: representing about 90% of total heat production. Renewables represented just about 5% of worldwide district heat supplies, although, as stated above, this share can be over ten times higher in some countries.
The IEA States:
“Aligning with the Net Zero Emissions by 2050 (NZE) Scenario requires significantly stronger efforts to rapidly improve the energy efficiency of existing networks and switch them to renewable heat sources (such as bioenergy, solar thermal, large-scale heat pumps and geothermal).”
So, how do we pool our efforts to create a more rapid uptake of renewable energy-powered district heating?
Building momentum for district heating networks powered by renewable sources
While 5GDHNs offer many benefits, they are not without challenges. Upfront costs can be significant, and retrofitting existing systems may be complex. Additionally, integrating various energy sources and technologies requires careful planning and investment.
But there is political will to change - driven by both climate targets and energy security challenges.
In April 2023, the European Union provided EUR 401 million in support for the Czech green district heating scheme.
In the United Kingdom, in March of this year, the Energy Security Bill introduced a heat networks regulation to enable heat zoning. The Climate Change Committee has estimated that around 18% of heat consumption in the United Kingdom could be supplied through heat networks by 2050.
Image Credit: Kensa Group
In partnership with Kensa Contracting, in 2019 the Genius Energy Lab team designed the ground loop and hydraulic arrangements at the largest shared ground source heat pump retrofit scheme in England. Sixteen shared ground loop systems served all eight of the Enfield tower blocks - with an individual Kensa shoebox heat pump installed in each flat to generate heating at point of need. Tenants’ bills, on average, were more than halved and an estimated 773 tonnes of CO2 is saved per year.
Image Credit: Kensa Group
“One of the great strengths of this system type is its flexibility and scalability. Shared ground loop systems can be featured in developments of just two properties (micro-district) whilst this project clearly demonstrates how the concept can be scaled up to much larger systems.”
Dr. Matthew Trewhella, Kensa’s Contracting Director (at time of install)
Waste not, want not: more on how GSHP comes into play in district heating networks
There’s further opportunity for networked heat pumps to be deployed as a district heating solution. A high-potential - and untapped - heat source exists everywhere – particularly in urban areas, where building heat demand is mostly concentrated: wastewater.
A recent study shows that almost 4,000 wastewater treatment plants in Europe are located less than 2 km away from a district heating network. These plants combined could deliver 175 TWh of heat to the networks per year using heat pumps, equal to one-fifth of the current district heating supply in Europe.
Ground source heat pumps’ role is clear - they can harvest waste heat sources such as data centres, metro tunnels, industrial facilities or electrolysers.
Case in point: the city of Vancouver, Canada, which is expanding its district heat network capacity by adding 6.6 MW of sewage heat recovery equipment to capture latent heat from wastewater with heat pumps.
The Katri Vala Heating and Cooling plant in Helsinki, Finland, employs large heat pumps which have a heating capacity of 126 MW using wastewater for space and water heating in residential buildings, as well as a cooling capacity of 80 MW using cool seawater for cooling office spaces.
If you'd like to continue your learning on GSHP - head to our resources area.
The Future Of Energy
Fifth-Generation Heat Networks powered by ground source heat pumps represent an exciting frontier in the quest for sustainable, efficient, and environmentally friendly energy solutions.
By embracing renewable energy, waste heat recovery, and smart technology, district heating networks hold the potential to significantly reduce carbon emissions, enhance energy resilience and create a cleaner and more cost-effective future.
GEL are the experts in assessing the feasibility and design of ground source arrays in district heating networks. We deliver award-winning designs for district heating networks and work alongside large-scale contractors, housing associations and developers throughout the UK and across Europe to deliver greener, smarter and more economical energy.
To learn more about GSHP in district heating networks and fifth-generation heat networks - and how we get to work, reach out to the team: whitecoat@geniusenergylab.com