The Demonstrator Projects


We live in a world where we can just flick a switch or push a button to turn on a light or the heating in our homes; but things are becoming less simple. Supplies of energy from fossil fuels are not sustainable, less secure, have seen rapid price increases and come at a cost to the environment we live in.

We are still very reliant on burning imported fossil fuels like oil, gas, and coal to generate electricity or heat our homes, schools, hospitals, and businesses. Potent greenhouse gases are released when we do this, which can pollute the air that we breathe and are contributing to our planet’s rapid warming.

Animation still showing how underground geothermal can be used to transfer heat to homes and buildings using aquifers at different depths

To achieve the vision for Northern Ireland to have affordable, net zero carbon energy and to help mitigate climate change, we need to move to low carbon, renewable and sustainable energy sources.

Northern Ireland has an overall goal of achieving net zero carbon energy emissions by 2050 as do other countries around the world. The Climate Change Act (Northern Ireland) 2022 is a piece of legislation that aims to legally ensure Northern Ireland contributes to the UK efforts to tackle climate change. In addition to the net zero carbon goals, there are also sectoral plans to support decarbonisation of carbon intensive sectors and a target of 80% of electricity from renewable sources by 2030.

If we achieve this, we will also be more energy self-sufficient and secure in the process. The good news is that Northern Ireland is already a powerhouse in its use of renewable energy, and we are currently harnessing the this through wind generation and via solar energy.


The latest Department for the Economy Energy report shows that 51% of total electricity consumption in Northern Ireland was produced by renewables. Wind energy continues to be the predominant source with 85.3% generated, compared to solar which generated 3.2%.

To secure our net zero energy future we also need to access a more diverse range of other renewable energy sources, including the geothermal heat beneath our feet. That is where the GeoEnergy NI project comes in.

Utilising this potential geothermal energy and helping to develop a geothermal sector will be extremely important in helping to achieve the targets laid out in our climate legislation.

Geothermal energy is a low carbon, natural, and renewable energy source from beneath the Earth’s surface. Unlike other renewable energy sources, it is available 24 hours a day, whatever the weather. It can provide ‘always on’ decarbonised energy to heat and cool our homes and buildings, as well as supporting our industries, and empowering our way of life.

In Northern Ireland, we are lucky to have favourable geological conditions with huge untapped potential for valuable geothermal energy right beneath our feet. In almost every part of Northern Ireland there is potential for some form of geothermal energy to be utilised. The type most applicable will depend on the land available, the quantity and temperature of heating or cooling required and the suitability of the underlying rocks and beneath a site to meet the requirements.

The GeoEnergy NI project will explore that potential through geothermal demonstrator projects in two separate locations in Northern Ireland, tackling shallow and deep geothermal potential. Each area will require a different range of studies to be undertaken.

A group of people all wearing hard hats, looking towards a rockface and listening to a man speaking.
A GSNI field study to Scrabo Tower, Northern Ireland in 2022.

The College of Agriculture, Food and Rural Enterprise (CAFRE) Greenmount Campus near Antrim and Stormont Estate in Belfast have been chosen as they directly overlie what is known to be one of Northern Ireland’s most widespread and productive aquifers. This aquifer is present at shallow depths under the Stormont Estate (being able to support a ground source heat pump system) and it is buried more deeply (and therefore should contain hot water) beneath Greenmount.

This project will ensure we better understand the availability of geothermal energy in Northern Ireland, and better utilise this locally available, cost-effective, renewable, and low-carbon resource for all our benefit.

By unearthing the geothermal resources beneath our feet, GeoEnergy NI will help pave the way for a more sustainable energy future – a future powered by the planet itself.


Geothermal energy has been tapped in the UK since Roman times, via the hot springs at Bath and elsewhere. Since then, the potential of geothermal energy on a commercial basis has been successfully exploited across the UK including in Cornwall, Southampton and Newcastle.

Photo by Paul Cuoco, Unsplash.


The Department for the Economy’s Energy Strategy: The Path to Net Zero, published in December 2021, sets out our path to 2030 as part of the longer-term pathway to achieve net-zero energy related emissions by 2050. It is believed that geothermal energy can play a significant part in helping achieve that target as well as helping secure our own energy supply.

The Climate Change Act (Northern Ireland) 2022 aims to ensure Northern Ireland contributes to the UK’s efforts to tackle climate change. In addition to the net zero carbon goals, there are also sectoral plans to support decarbonisation of carbon intensive sectors and a target of 80% of electricity from renewable sources by 2030.


The Department for the Economy (DfE), with scientific support from the Geological Survey of Northern Ireland (GSNI) are delivering this project with a specialist contractor team.

The key project partners are:

DfE is responsible for Northern Ireland’s wider economic policy, including the region’s energy policy.

In December 2021, The Department for the Economy’s Energy Strategy: The Path to Net Zero was published which recognised the role that geothermal energy has to play in decarbonising how we heat and cool our homes and buildings.

The Department’s 2022 Energy Strategy Action Plan showed the commitment to developing and commencing delivery of a geothermal demonstrator project as part of its pathway to reach net-zero targets by 2050.

In June 2022, the Department for the Economy recognised the importance of ensuring that there is a secure supply of locally available energy, and therefore announced that up to £3 million of funding had been secured for this project. Designed to evaluate the potential and suitability of harnessing geothermal energy, the ultimate aim for GeoEnergy NI is to showcase the untapped potential that geothermal energy has to provide a clean and renewable heating, cooling and electricity solution and to encourage future private sector investment in this technology within Northern Ireland.

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The Geological Survey of Northern Ireland (GSNI) is an office of the Department for the Economy (DfE) in Northern Ireland staffed by scientists of the British Geological Survey (BGS). GSNI provides professional, technical, and scientific research, data services and information management to inform the development of NI’s economy and to help protect its environment.

GSNI also collaborates on geoscience research with the BGS, the Geological Survey of Ireland and over 35 universities globally. GSNI actively engages and works with all parts of civic society, including central and local government, industry, academia, communities, non-governmental organisations (NGOs), schools and the public.

GSNI is the lead science partner on this project; its scientists have helped scope the project’s design, written the technical specifications, are supporting the project’s delivery, and will interpret the results and provide advice into future policy decisions.

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The successful lead contractor is Tetra Tech who will lead a consortium of specialist partners to deliver the two demonstrator projects and associated communications campaign.

Tetra Tech is a global provider of consulting and engineering services. Leading with science they help international, commercial and government clients solve some of the world’s most complex problems, providing innovative, sustainable, and resilient solutions for various challenges in water, environment, sustainable infrastructure, renewable energy, and international development. They have a particular specialism in geosciences including in geothermal technologies.

They will be the main engineering partner in this project and help to drive the sustainability and quality of the overall technology used in the drilling of the boreholes.

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The Department for the Economy’s Energy Strategy: The Path to Net Zero Energy, published in December 2021, sets out our path to 2030 as part of the longer-term pathway to achieve net-zero energy related emissions by 2050. It is believed that geothermal energy can play a significant part in helping achieve that target as well as helping secure our own energy supply.

The Climate Change Act (Northern Ireland) 2022 aims to ensure Northern Ireland contributes to the UK efforts to tackle climate change. In addition to the net zero carbon goals, there are also sectoral plans to support decarbonisation of carbon intensive sectors and a target of 80% of electricity from renewable sources by 2030.

Therefore, realising the potential of geothermal energy and developing a geothermal sector will be extremely important in helping to achieve the targets laid out in the Act and delivering the Energy Strategy vision of net zero carbon and affordable energy for Northern Ireland.



The ability to provide renewable heat, as the heat coming from the Earth’s interior (or at shallow depths from the Sun) is replenished and therefore will continue for billions of years.

Offering a sustainable, low-carbon alternative to fossil fuels.

Local availability as this energy source is available beneath our feet, which will increase the security of our energy supply.

Geothermal energy is reliable, constant and available 24 hours a day, 365 days per year, whatever the weather.

Can be harnessed from depths of just a few metres to several kilometres to heat our homes, workplaces and leisure facilities, and to replace fossil fuels in heat-intensive industrial and agricultural processes.

Has the potential to supply all the renewable, decarbonised heat we need, many times over.

Geothermal energy is multi-functional, it can be used to heat and cool homes or store heat seasonally.

In some circumstances, geothermal can also be used to generate dispatchable, low carbon electricity.

Has minimal visual impact – with the smallest surface footprint of any renewable energy source.

Geothermal systems have long life spans with many systems able to operate for up to 100 years with only routine maintenance required.


The data and learnings from the GeoEnergy NI project will help refine our understanding of the subsurface in Northern Ireland, which will be essential to help us unearth the heat beneath our feet. It will also support the development of a geothermal industry here, which would produce many high value jobs and skills through direct employment and spin-off industries.

Based on a study by the Geothermal Energy Association (US) published in 2014, for every 100 megawatts (MW) of installed geothermal capacity an estimated 170 permanent high-quality jobs are created, as well as an additional 640 full time jobs in annual construction and manufacturing.  The report also pointed to the industry’s contribution to the development of academic and engineering excellence in the regional universities and colleges.

From the information obtained during these studies, we hope to:

1. Demonstrate that a viable geothermal heat resource is accessible at depth that could be used for heat networks or industrial use.

2. Provide confidence to local people when deciding on whether to install a shallow geothermal heating or cooling system.

3. Encourage investment by making more detailed information available on the current regulatory system.

4. De-risk private sector projects by making more detailed information about the subsurface publicly available.

5. Inform the development of a policy and regulatory framework that supports and promotes opportunities to unearth Northern Ireland’s geothermal potential and create a vibrant geothermal sector.


Recent analysis of geological data across Northern Ireland by GSNI has identified areas with greatest potential for geothermal.

Shallow geothermal can be accessed in most locations using a ground source heat pump. Large scale geothermal systems can be effective in shallow rocks that either have good thermal conductivity or are good aquifers. The sandstones present around Belfast rank highly in both these categories. The same rocks are present elsewhere and buried to greater depths in parts of Northern Ireland where the waters within the sandstones will have potential to be a deep geothermal resource. The area around Antrim is one such region with deeply buried sandstones.

The GeoEnergy NI demonstrator project will initially focus on two key locations in Northern Ireland; CAFRE Greenmount Campus near Antrim and Stormont Estate in Belfast. Each location will have its own specific set of studies and exploration techniques.


Photo taken outside Stormont Parliament Buildings in East Belfast.
Parliament Buildings, Stormont Estate, Belfast

This feasibility study, which is subject to planning permission, will be primarily focused on shallow geothermal with the aim to identify the most suitable geothermal solution to potentially provide heating and cooling for several buildings on the Stormont Estate in the future.  Here it will involve the drilling and testing of five boreholes, four of which will be hydrogeology boreholes around 250 metres deep, and one borehole will be cored to 500 metres depth. A series of tests and analyses will be done on the boreholes following the drilling. The boreholes will be predominantly located in private areas of the estate near government buildings west of Stoney Road and the area around Dundonald House and Castle Buildings.

The Stormont site is underlain by a near surface aquifer containing groundwater in the region of 15 °C. Shallow systems generally require Ground Source Heat Pumps (GSHP) to increase the low temperature obtained from the geothermal resource for use in domestic or commercial heating applications.

One of the key objectives of the feasibility study at the Stormont Estate is to understand whether a closed-loop or open-loop GSHP system are most suitable, and to calculate resource and the carbon savings that could be made by using geothermal energy. The data gathered will help optimise the capital expenditure and operation expenditure costs of any future geothermal heating system.

It is hoped the project on the Stormont Estate will result in a future geothermal heat network that will replace the current fossil fuel heating systems at some of the buildings on the Estate. Ultimately this will help Northern Ireland meet the Executive’s carbon reduction targets as well as reducing and stabilising heating costs.


Birds eye view of the College of Agriculture, Food and Rural Enterprise - CAFRE. Showing multiple buildings on site.
Aerial view of The College of Agriculture, Food and Rural Enterprise (CAFRE), Co. Antrim.

A deeper geothermal feasibility study will be based in and around the College of Agriculture, Food and Rural Enterprise (CAFRE) Greenmount Campus near Antrim. This project will include identification of potential target depths for future drilling, suitable heat recovery systems and available uses for deep geothermal energy in Northern Ireland. Included in the project will be ground-based geophysical surveys to provide drilling prognosis, identification of the optimum location for future drilling, risks and mitigation and imaging any geological structures and potential water zones. At this stage, the planned Greenmount works do not involve any exploratory drilling.

The project will however incorporate geophysical methods including seismic reflection, magnetotelluric and gravity surveys. By utilising these methods, it will help to build a picture of the deep rocks below the surface.

The Greenmount Campus location was chosen because it lies above deeply buried porous sandstones that are likely to contain naturally occurring hot water (potentially around 70 °C) at depths of two to three kilometres. These are the same sandstones that also underlie the Stormont Estate, at shallower depth. This deep aquifer is an exciting geothermal energy source and presents an opportunity to explore the future development of a geothermal district heating network or, potentially, to decarbonise horticulture or other agri-food processes.

The project will take place in the grounds of the campus and due to the nature of the site and location as well as the studies being undertaken it is not accessible to the public. The non-invasive nature of the exploratory techniques at the site means that no planning permission is required at this stage. Any future drilling will require planning permission as well as environmental assessments and permits.


An area the size of Belfast in the Netherlands is covered by greenhouse farms using geothermal energy to heat their greenhouses and produce food and tulips. With their high light transmittance and higher insulation value, the greenhouses require far less heating energy than that required by conventional structures.

Photo by Who’s Denilo?, on Unsplash


By unearthing the geothermal resources beneath our feet, GeoEnergy NI will help pave the way for a more sustainable energy future – a future powered by the planet itself. A mobile GeoEnergy Discovery Centre will be used as a resource to inform the public, stakeholders and schools about the exciting potential of geothermal energy.

As well as the GeoEnergy Discovery Centre roadshow activity in February, you can visit the centre on the Stormont Estate in April.

We have different visiting options available, you can either book a group visit to our mobile centre or you can visit on one of our selected drop-in sessions.

Mo Mowlam Playpark, Stormont Estate, April 2024 opening times will be displayed here when they have been confirmed. 

Date Opening Times Visit Type


What to expect at our GeoEnergy Discovery Centre:

Virtual Reality and Augmented Reality headsets designed to show you the journey of geothermal energy and how it can be utilised in creating a "flexible, resilient and integrated energy system” (Department for the Economy, The Path to Net Zero, December 2021).

Information on the uses of geothermal energy and how you could potentially benefit from this renewable, sustainable energy source.

A chance to handle and see first-hand, the different types of rock found at different depths.

Information on the future potential of geothermal energy in Northern Ireland and a chance to ask our specialists questions about geothermal energy.

A chance to see a borehole – what it looks like, how it was created and the small surface footprint associated with it.

Drilling of the borehole (this will be project dependent and if there is drilling on-going at the time).


The two feasibility studies will utilise a range of different technologies for drilling and inspecting the boreholes, for mapping data gathered and also for assessing the thermal properties of the boreholes.

As the works are exploratory in nature, a wide range of borehole tests are planned to help evaluate the potential for use of ground source energy.

The planned tests include:

  • Downhole CCTV or camera surveys.
  • Downhole geophysical surveys to help understand changes in the ground properties with depth.
  • Pumping tests, where water is pumped from the boreholes at differing depths and volumes to better understand how water flows through the aquifer. Water pumped from the boreholes will also undergo analysis to determine the water quality.
  • Thermal Response Tests (TRT) to evaluate the ease at which heat moves through the ground.
  • Gravity survey
  • Seismic reflection
  • Magnetotelluric survey
A blue and white lorry carrying a mounted drilling rig which can be utilised for drilling holes in to the ground.
Geothermal drilling rig from Geo Drilling


View of the drilling rig to show the drill bit and the mechanics of the rig.


At this stage of the project, drilling will only take place on the Stormont Estate (subject to approval from the relevant planning authorities). Due to the relatively shallow depths that will be drilled to, a mobile drilling rig mounted on a truck will be utilised. These drilling rigs use the same technique as conventional water well drilling and are routinely deployed in Northern Ireland. The rigs will be temporary structures with an overall height of around 12 metres.

Most boreholes are drilled using a motorised drilling rig.

Rotary drilling is the most common method for water borehole drilling and can be; air flush, sometimes with down-the-hole hammer; mud flush; or reverse circulation. Find out more in the Africa Groundwater Atlas. 2019. Borehole Drilling. British Geological Survey.

As the drilling rigs at both sites are temporary, once the drilling is complete, the rig will leave the site so that the testing of the borehole can be carried out.



A borehole CCTV camera survey will allow the team to look down the borehole to see the casing, and underlying geology in real-time. This will enable geologists or engineers to identify any issues and locate where water is entering through fractures and fissures into the borehole.



Downhole geophysical surveys, including groundwater temperature, single-point resistance, electromagnetic induction, gamma, and fluid resistivity will be recorded and analysed to assess the physical properties and conditions within the borehole. Logging this information is critical as it helps to give a better understanding of subsurface conditions and is needed for any future geothermal infrastructure to be installed.

The results of these surveys will be vital in determining any future geothermal plans for Northern Ireland.


A thermal response unit stationary on flat ground with a background of mountains and water.

Photo provided with permission of  © Carbon Zero Consulting Ltd


As the thermal properties of a borewell cannot be measured directly, thermal response tests are used to determine the thermal properties of the ground.  A Thermal Response Test (TRT) is vital for designing geothermal heating systems that use ground source heat pumps. A TRT is an easy and convenient method to determine thermal properties in the ground.  The test involves circulating a heated fluid and continuous logging of temperatures of the fluid at the inlet and outlet.


A man wearing high visibility jacket checking a piece of equipment used in geophysical surveys, whilst crouched down on grass.


Gravity surveys use a small device called a gravimeter that provide measurements of tiny variations in the Earth’s gravitational field between different locations. These variations result from changes in the different densities of different rock types below.


Drone image of a vibroseis truck that is being used for surveys in CAFRE Greemount campus near Antrim. This truck belongs to GeoPartner.


A seismic reflection survey involves low-frequency acoustic waves generated by a Vibroseis truck which are then recorded by a series of sensitive receivers. These waves travel at different speeds through different rocks and they are received at different times by the recording instruments, which allows us to build up a picture of the rock layers underneath the surface.


A male and female laying cable in to the ground. Both people are wearing high visibility jackets and hard hats.


Magnetotelluric surveys involve the burial of some magnetic coils and electrodes that are left overnight to measure small variations in the Earth’s electromagnetic field. These are picked up by the equipment which can measure tiny changes in electrical current and give us the properties of the rocks buried below this site.




In terms of utilising geothermal energy in Northern Ireland, based on the most accessible resources there are several well-established technologies that could be used. Shallow geothermal is mostly accessed by systems that involve heat pumps and installation of some underground infrastructure. Deep geothermal can provide greater amounts of heat for industrial processes, large amounts of houses or electricity and normally requires deep drilling and the building of a geothermal plant and/or installation of a heat network. Shallow geothermal has the widest potential use across Northern Ireland and is considered below. The Stormont Estate part of this project will assess and showcase the potential for shallow geothermal.


You almost certainly already have a heat pump in your home – your fridge or freezer.  A heat pump is a device takes natural background heat from ground or air and upgrades the heat to temperatures suitable for heating houses, offices, and many other types of buildings. Other end uses could include heating swimming pools. Heat pumps can also be operated in reverse to provide cooling when required.

Low temperature heat energy delivered to the heat pump is upgraded, through interaction with a compressor and condenser, to achieve an elevated temperature which can be transferred to a building’s heating system. Heat energy from a heat pump is typically delivered to a building through traditional radiators, underfloor heating and air heating systems. The heat pump can also be designed to work in reverse and extract heat from the building space, to provide cooling.

Heat pumps are a very efficient way of providing heating for buildings. They represent a low carbon replacement option for existing combustion fossil fuel systems such as oil and gas boilers. There are no emissions from heat pumps which helps to improve air quality. Heat pumps are powered by electricity but typically for every one kilowatt of power used, three to four kilowatts of renewable energy is generated.



Pipes being laid for geothermal purposes at Girdwood Community Centre.
Laying the geothermal foundations at Girdwood Community Hub, Belfast

Ground source heat pumps (GSHP) can be used for all building types from single houses to large offices. Schemes have been implemented in apartment blocks, with small heat pumps installed in individual flats or apartments, connected to a buried borehole array adjacent to the building.

Many homeowners across the world are making the switch to the renewable energy source due to the outstanding benefits geothermal can offer. These include reductions in carbon emissions, energy and cost savings and the flexibility to be able to heat and cool homes even in adverse weather conditions.

For more information on ground source heat pumps, visit NI Direct.

Associated organisations


Ground Source Side

  1. Closed-loop outlet brine temperature
  2. Inlet brine temperature
  3. Brine flow rate
  4. Consumption of brine circulation pumps
  5. Ground temperature (single, multi-point sensors, and or fibre optic DTS, etc.)
  6. Inflow groundwater temperature
  7. Outflow groundwater temperature
  8. Groundwater flow rate
  9. Injection well water level
  10. Production well water level
  11. Monitoring well water level
  12. Electricity consumed by submersive pump

Building and Heat Pump Plant Room Side

  1. Electrical consumption of GSHP
  2. Thermal energy meter
  3. Electrical consumption of circulation pumps
  4. Electrical consumption of terminal units
  5. Inner room temperature & humidity
  6. Ambient or outside air temperature and humidity
  7. Data logger and remote data transfer unit
  8. DHW storage tank temperature
  9. Buffer and decoupling storage tank temperature

GSHP  Ground Source Heat Pump
BHE     Borehole Heat Exchanger
GWL    Ground Water Level
DTS      Distributed Temperature Sensing
Hex      Plate Heat Exchanger (with filter)
DHW   Domestic Hot Water

Graphic showing the different types of ground source heat pumps, along with numbers that match up to what each is representative of.

Figure 1 depicts the types and locations of sensors for monitoring ground source heat pump (GSHP) systems based on experiences shared within the MUSE project consortium (2018-21). 


An open-loop system comprises boreholes drilled into the porous underlying rock, sands or gravels (aquifers) and utilises groundwater for the heat exchange process in connection with a ground source heat pump. The system will use clean groundwater, transferring the heat via the pump, and then returning the water back to the aquifer through a second borehole far enough away from the extraction borehole so that the returned water has time to re-heat and the cycle of waters is not short-circuited.

Fresh water is a must for an open loop system to work effectively but the systems do come with some drawbacks. For example, there is an increased risk of debris (sand grains) or mineral precipitates blocking the system. Therefore, the lifecycle of an open-looped GSHP requires a greater understanding of the aquifer, water chemistry and usually requires a higher level of maintenance than closed-loop systems.

However, despite the drawbacks, if a suitable aquifer is present, a system can be designed to provide greater amounts of heat or cooling with less drilling (i.e., upfront cost) than for closed-loop.


Sealed pipes buried beneath the ground recirculate fluids in a sealed system providing cooling and heating to your home through a connected indoor heat pump.

A closed-loop system will continually circulate this fluid within the pipes and therefore only requires a small volume of fluid. The same fluid is recycled and used repeatedly, in a “closed-loop”. Closed-loop GSHP systems can either be installed horizontally by excavating trenches a few metres deep, or vertically by drilling a borehole around 100 metres deep for a domestic property.

The major benefits of a closed-looped system are the longevity of the ground collector pipe and the minimal maintenance to the system which in turn ensures that cost over time can be lower than that of an open loop system although for large heat requirements multiple boreholes will be required to be drilled, which can increase the initial cost compared to an open-loop system.


The UK’s largest, most celebrated art deco sea water lido (the Jubilee Pool, Cornwall) is geothermally heated. This lido is a naturally heated sea pool that reaches temperatures of up to 35 degrees.

Photo by Benjamin Elliott on Unsplash.


Download all our information including brochures and reports and watch videos in relation to the GeoEnergy NI project.

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