Project Description
To achieve the Low Carbon Energy Transition and the challenge of meeting Net Zero it is necessary to identify and develop economically-viable, low carbon energy sources that have limited environmental impact. Geothermal energy provides such an opportunity. Despite the considerable potential of geothermal energy, to date there has been little commercial success in the UK. Historically, big capital projects have focussed on power generation in high enthalpy fractured Cornish granites; progress has been steady but slow. Feasibility studies have also addressed deep sedimentary aquifer potential across the UK, but most projects have significant geological risk and high well cost. In contrast, low enthalpy geothermal energy obtained from shallow (<200 m) groundwater sources is relatively low cost and utilises well-established technology. The Closed and Open loop Ground Source Heat Pump (GSHP) industry in the UK is growing, however it is the often the case that development of open loop resources is prevented through poor subsurface understanding.
We aim to establish the low enthalpy geothermal potential of northern Scotland (north of the Central Belt) and Northern Ireland by: a) auditing the shallow geothermal resource across Northern Ireland and northern Scotland, b) grading areas based on their economic heat source potential and, if possible, 3) progressing preferred options to a high-level business case.
To audit the low enthalpy geothermal resource an initial desktop study of the distribution of potential shallow geothermal aquifers will be undertaken. Work will focus on shallow gravel aquifers of Plio-Pleistocene and Quaternary age. The student will utilise base maps and expertise provided by the Geological Survey of Northern Ireland (GSNI) and the British Geological Survey (BGS). Once identified, focus areas will be subject to more detailed study including the use of shallow geophysical techniques to constrain depth to bedrock, gravel aquifer internal properties and fluid content.
Geological field mapping to determine aquifer characteristics will be undertaken. Establishing the depositional environment will be key to assessing characteristics such as porosity and permeability distribution, for example ice contact deltas, glacial outwash sheets and tunnel valleys all have significantly different heterogeneity distribution which will impact volume and aquifer flow rate. A set of screening criteria for shallow aquifer prospects will be developed which as well as geological characteristics will also include environmental (e.g. water disposal mechanisms, salinity and metal content) and economic (e.g. evidence of demand, plus possible water cooling requirements of some industries) aspects. Following these studies, two or more sites will be selected for further feasibility work including simulation to establish economic potential, with at least one site located in Northern Ireland and one in northern Scotland.
Project rationale:
To achieve the Low Carbon Energy Transition and the challenge of meeting Net Zero it is necessary to identify and develop economically-viable, low carbon energy sources that have limited environmental impact. Geothermal energy provides such an opportunity. Despite the considerable potential of geothermal energy, to date there has been little commercial success in the UK. Historically, big capital projects have focussed on power generation in high enthalpy fractured Cornish granites; progress has been steady but slow. Feasibility studies have also addressed deep sedimentary aquifer potential across the UK, but most projects have significant geological risk and high well cost. In contrast, low enthalpy geothermal energy obtained from shallow (<200 m) groundwater sources is relatively low cost and utilises well-established technology. The Closed and Open loop Ground Source Heat Pump (GSHP) industry in the UK is growing, however it is the often the case that development of open loop resources is prevented through poor subsurface understanding.
Aims & Objectives:
The aim of this project is to establish the low enthalpy geothermal potential of northern Scotland (north of the Central Belt) and Northern Ireland, both areas which have received more limited consideration of their geothermal potential. The research has potential to encourage successful projects by de-risking the resource and could assist with providing cheap, green and reliable sources of heating or cooling, in rural “off-grid” settings, that are less connected to existing gas networks. The project has 3 main aims to: a) audit the shallow geothermal resource across Northern Ireland and northern Scotland, b) to grade areas based on their economic heat source potential and, if possible, 3) to progress preferred options to a high-level business case.
Approach:
To audit the low enthalpy geothermal resource the student will perform an initial desktop study of the distribution of potential shallow geothermal aquifers in Northern Ireland and Scotland. The general geological history of the two areas has strong similarities and regional scale approaches to mapping will be applicable to both regions. In the initial phase, the study will focus primarily on shallow gravel aquifers of Plio-Pleistocene and Quaternary age and, where applicable, may be supplemented by work on underlying bedrock aquifers. The student will utilise base maps and expertise provided by the Geological Survey of Northern Ireland (GSNI) and the British Geological Survey (BGS) as a starting point. Once identified, focus areas will be subject to more detailed study including the use of a suite of shallow geophysical techniques to constrain depth to bedrock, gravel aquifer internal properties and fluid content. The combination of shallow seismic reflection and refraction (P-wave velocity/density), passive seismic surface wave (S-wave velocity/density), resistivity tomography (conductivity) and ground penetrating radar (GPR, dielectric permittivity/velocity) will provide detailed site-specific subsurface models.
Detailed geological field mapping to determine aquifer characteristics will be undertaken. Establishing the depositional environment will be key to assessing characteristics such as porosity and permeability distribution, for example ice contact deltas, glacial outwash sheets and tunnel valleys all have significantly different heterogeneity distribution which will impact volume and aquifer flow rate. A set of screening criteria for shallow aquifer prospects will be developed which as well as geological characteristics will also include environmental (e.g. water disposal mechanisms, salinity and metal content) and economic (e.g. evidence of demand, plus possible water cooling requirements of some industries) aspects.
Following these studies, two or more sites will be selected for further feasibility work including simulation to establish economic potential, with at least one site located in Northern Ireland and one in northern Scotland at a minimum.
The student will be trained in a range of applicable techniques including geological mapping, 3-D visualisation of subsurface data, groundwater flow modelling, geophysical data acquisition and processing and borehole analysis, thus providing a range transferrable skill sets that can be utilised in subsurface facing industries. The student will also be exposed to broader analysis of environmental and economic aspects. The project will benefit from quarterly meetings with TownRock Energy, a geothermal energy company who have agreed to provide advice throughout the project, Tim Kearsey (BGS groundwater specialist, Scotland) and Rob Raine (GSNI energy geologist, Northern Ireland).
Essential & desirable candidate skills
Essential: Geoscience or related degree
Desirable: Masters level geoscience or related degree
Photo credit: The advert image has kindly been provided by The British Geological Survey (BGS)
Supervisors
Adrian HartleyPrimary Supervisor: | Profile: Adrian Hartley Email: a.hartley@abdn.ac.uk Institution: University of Aberdeen Department/School: School of Geosciences |
Ulrich OfterdingerSecondary Supervisor: | Profile: Ulrich Ofterdinger Email: U.Ofterdinger@qub.ac.uk Institution: Queen's University, Belfast Department/School: School of Natural and Built Environment |
Clare BondPrimary Supervisor: | Profile: Clare Bond Email: clare.bond@abdn.ac.uk Institution: University of Aberdeen Department/School: School of Geosciences |
Additional Supervisor: | Dr. Rob Raine – Geological Survey of Northern Ireland has considerable experience in the assessment and understanding of geothermal systems (both deep and shallow) and will provide valuable access to data for mapping and assessment of resource. Dr. David Cornwell – University of Aberdeen has considerable experience of the application of shallow geophysical techniques to define parameters that will be important in assessing groundwater potential (e.g. resistivity, passive seismic, gravity, magnetics) which will help to determine depth to bedrock and heterogeneity within potential aquifers. |
Research Methods
Use of GIS techniques to map potential aquifer sites using BGS datasets. Geophysical techniques such as seismic reflection and refraction, passive seismic surface wave, resistivity tomography (conductivity) and ground penetrating radar to define aquifer area. Geological techniques: field mapping, interpretation of borehole and flow data, reservoir model builds to determine resource potential.
Expected Training Provision
The student will be trained in a range of applicable techniques and will also be exposed to broader analysis of environmental and economic aspects. The project will benefit from quarterly meetings with TownRock Energy, a geothermal energy company, and the expertise of the BGS and GSNI).
Training in GIS, sedimentology, field mapping and geophysical techniques will be provided by Aberdeen and Belfast supervisors, and, where applicable supplemented by suitable training courses provided by software companies (e.g. Petrel and Eclipse in reservoir modelling). TownRock have agreed to provide mentoring regarding site selection, suitability and feasibility criteria.
Impact
This research aims to reduce fuel poverty in rural communities in Northern Ireland and northern Scotland through the provision of a low cost, environmentally-friendly geothermal heat source solution. If successful, the approach could have significant application elsewhere in the UK and beyond.
Through the audit process the aim is to map areas that have significant shallow geothermal potential and which may be appropriate for use of open source heat loop technology. These maps will be made publicly available and will provide a baseline for the shallow geothermal potential of Northern Ireland and Scotland. This is an important resource that could be utilised subsequently by a range of stakeholders, particularly with future technological developments.
The geothermal potential of the UK is untapped and has been largely ignored with focus to date on fractured, deep bedrock aquifers that have unpredictable flow rates and high drilling costs (e.g. Cornish granites). The aquifers targeted in this proposal mitigate against these problems with the glacial gravels having high flow rates and predictable geometry and internal heterogeneity and are restricted to a few tens of metres below the surface. The approach utilises a proven technology in a setting where the geological context is known but has not been mapped in detail.
This multidisciplinary study combines a wide range of skill sets in the geosciences but also has important implications for environmental planning and future energy use scenarios. It brings together key stakeholders in the two regions and will impact, local communities as well as regional and national policy makers.
Proposed Supervision
Hartley, Ofterdinger, Bond, Raine, Cornwell & Kearsey
Proposed Timetable
Year 1: Auditing the shallow geothermal groundwater resource of the study areas. Establishing a GIS project with all existing mapped data, reviewing and collating published data and combining this with pre-existing mapping by BGS in Scotland and GSNI. Literature review of shallow groundwater aquifers and establishment of key geological, economic and environmental criteria for future screening. Publication of map of shallow geothermal potential in the study areas.
Year 2: Establishing a shortlist for areas that have the potential for further study following screening ultimately aiming for one focus site in northern Scotland and one in Northern Ireland. Once identified, sites will be subject to detailed field investigation, geological mapping initially. Economic and environmental considerations will also be documented. Publication of field results. Presentation at national/international conference.
Year 3: Detailed field investigations in the two selected study sites. Once the sites are defined geophysical techniques can be utilised to determine subsurface characteristics. Publication of geophysical results. Presentation at international conference.
Year 4: Write up and publication of final results. Results to be presented at international conference.
Partners
The project will receive contributions from:
Dr. Rob Raine – Geological Survey of Northern Ireland
The project will benefit from quarterly meetings with TownRock Energy, a geothermal energy company, and the expertise of the BGS and GSNI.
TownRock Energy have agreed to provide mentoring regarding site selection, suitability and feasibility criteria.
