Data centres in Scotland: a guide to our regulatory role
Overview
Data centres may be subject to multiple environmental regulation regimes, depending on their design and operation. While SEPA do not regulate data centres as standalone facilities, we do have a role in associated activities.
This guide is designed as an overview of our remit in these areas, along with information on related UK schemes. It is written in the context of:
- the Environmental Authorisation (Scotland) Regulations 2018 (EASR)
- the Scottish Government’s Green Datacentres and Digital Connectivity Vision and Action Plan
- the UK Government’s AI Growth Zones (AIGZ) initiative
The planning process
Our Development Management Consultation Thresholds and Standing Advice guidance sets out the circumstances in which planning authorities should consult us on applications. Consultation triggers for data centres may include flood risk or development on peat/carbon rich soil. Proposals that fall below our consultation thresholds are covered by the standing advice.
National Planning Framework 4 policy 22 (flooding) includes limited support for development proposals at risk of flooding or in a flood risk area, including for essential infrastructure, where the location is required for operational reasons. Essential infrastructure includes digital communications infrastructure. SEPA's Flood Risk Standing Advice for Planning Authorities covers essential infrastructure developments where there is no land raising or loss of floodplain capacity.
The Scottish Government’s Energy Consents Unit (ECU) administers energy infrastructure applications that are made to Scottish Ministers under Section 36 and Section 37 of The Electricity Act (1989) if the application exceeds 50MW electricity generating capacity. Applications below the 50MW threshold are made to the relevant planning authority. It is for the relevant competent authority to make an Environmental Impact Assessment (EIA) screening determination.
Hazardous substances consent regulates the presence of hazardous substances to ensure risks to people and environment are properly addressed in land use planning. It is required from the planning authority (in consultation with both HSE and SEPA) for substances under Schedule 1 of The Town and Country Planning (Hazardous Substances) (Scotland) Regulations 2015, which includes certain fuels and chemicals such as diesel, cleaning fluids, and oils that might be present on the quantities specified at data centres.
On-site combustion plant
Data centres may require a large number of back-up generators which provide contingency to maintain operations in the event that grid supply is lost. They could also include further on-site energy generation 'embedded generation', such as baseload, mid-merit or peaking plant, to cover for insufficient grid capacity for the centre to operate during normal and peak demand periods.
The operation of combustion plant for back-up and embedded generation at data centres are activities regulated by SEPA under EASR. The level of authorisation will depend on the rated thermal input. Links for further information are available on Combustion of fuels authorisations.
Combustion of fuels in installations with a total input of 50MW or more need to be operated utilising Best Available Techniques (BAT). Permit application will need to demonstrate that BAT will be utilised to operate the combustion plant.
For back-up power generation, new plant should utilise the lowest emission unabated engine available (e.g. equivalent to 2g Luft standard or US EPA II). Embedded generation installations will need to demonstrate that they can meet the more stringent emission limits. Energy efficiency and waste heat recovery requirements could also apply (i.e. the requirement for a cost-benefit assessment to meet the Energy Efficiency Directive). Embedded generation applicants are advised to contact SEPA at the earliest opportunity.
Air emissions
Emissions Trading Scheme (ETS)
The UK Emissions Trading Scheme (UK ETS) is a key policy introduced by the UK to reduce greenhouse gas (GHG) emissions. UK ETS will also contribute to delivering Scotland's goal of a 75% CO2 reduction by 2030 and net zero emissions by 2045.
Data centres with embedded and back-up power generation are typically covered under the UK ETS due to their combustion activities. The combustion threshold for inclusion in the UK ETS is met for installations where the total rated thermal input from all stationary combustion units (of above 3MWth individually) exceeds 20MWth. Where an installation is in scope of the UK ETS, they will need to apply for a GHG Emissions Permit before the commencement of regulated activities.
We would encourage any new or prospective installations to email emission.trading@sepa.org.uk at the earliest opportunity.
Air quality
The main source of air emissions from data centres that could affect air quality is on-site combustion from back-up and embedded generation systems. It is likely that developers will need to carry out an air emissions impact assessment.
Data centres should utilise the lowest emission, most energy efficient, generating technology. The use of Hydrotreated Vegetable Oil (HVO) in combustion plant, as an alternative to traditional fossil fuels such as diesel, is considered to have a lower carbon footprint than fossil fuel diesel. However, HVO can still give rise to air quality impacts (including NOx emissions). It is vital that any HVO used is secured from a sustainable supply.
Energy use and storage
Data centres are energy intensive primarily because of the cooling demand required to maintain their functionality.
The Energy Saving Opportunities Scheme (ESOS) is a mandatory energy assessment scheme for organisations in the United Kingdom that are regarded as a ‘large undertaking’. They are defined based on the number of employees, annual turnover and being part of a corporate group where the parent company is defined as a ‘large undertaking’.
Battery energy storage systems
Energy intensive sites such as data centres, may incorporate Battery Energy Storage Systems (BESS) and should minimise the operation of peaking combustion plant.
Water abstraction and discharge
Water abstraction
Under EASR the abstraction of water outside the public water supply is an authorised activity regulated by SEPA. The level of authorisation will depend on the volume of water abstracted.
Abstractions from the public water supply require agreement from Scottish Water.
Data centres may need a significant amount of water to run their cooling systems. Pre-application discussions are recommended to ensure sufficient water is available throughout the year, including periods of water scarcity. The selection of an appropriate cooling system and water supply in the early stage of a project is critical. Any proposal to use abstracted inland surface water should be aware that the authorisation will have a hands-off flow condition applied, which will restrict access to water abstraction to protect river flows during low flows. This means there may be occasions where the authorised abstraction would have to stop.
Hierarchy of water supply:
- Treated effluent
- Seawater
- Ground/surface water
- Treated public supply should be the last option
Minimisation and reuse within the process should be considered and highlighted in all cases. The developer should be aware of any seasonal disruptions in water supply. The impacts of climate change are likely to result in increased periods of water scarcity as well as flooding. Storage of water on site should also be considered.
Obtaining an appropriate water supply may require works that are remote from the main development site. Where possible, this should be presented and consulted upon, considering all infrastructure including water supply. Selection of supply should also take account of potential prohibition of raw water transfer between catchments to prevent spread of invasive non-native species.
Water discharge
Typical constituents of cooling water discharges can include solids, pH, treatment components such as chemical dosing for dealing with fouling, corrosion etc as well as anything present in the cooling feedwater. Heat is also a potential pollutant, depending on the temperature of the effluent.
These discharges would be considered a trade effluent, and, under EASR, authorisation may be required for water discharges, managing potential contamination from cooling systems, discharge water temperature, and ensuring proper treatment of wastewater before release.
Discharge to sewer would be managed by Scottish Water and where required SEPA would regulate such flows at the Scottish Water works discharge.
Please email waterpermitting@sepa.org.uk for more advice on water abstraction and discharge.
Cooling gases (F-Gas)
Data centres might use F-gases in cooling systems, i.e. chiller plant and/or air conditioning units. If this is the case the site needs to comply with the Fluorinated Greenhouse Gas Regulations 2015.
Operators of equipment containing F-gases must comply with several obligations that include keeping an F-gas register, conducting leak checks by F-gas certified personnel, and keeping the required records.
Gases which can be used as alternatives to F-gases include natural refrigerants and certain unsaturated F-gases with a low global warming potential (GWP). The main alternatives include:
- Natural refrigerants – these are non-fluorinated, very low GWP substances which include carbon dioxide, ammonia, and hydrocarbons such as propane and butane.
- Low GWP synthetic gases – these are typically unsaturated fluorinated gases known hydrofluoroolefins (HFOs) and HFO/HFC blends, which break down faster in the atmosphere.
The specific choice depends on the application, such as industrial cooling, commercial refrigeration, or air conditioning, due to difference in flammability, toxicity and operating pressure.
Electrical equipment
Electrical equipment such as IT equipment used in data centres is in scope of the Waste Electrical and Electronic Equipment (WEEE) Regulations.
Under the WEEE Regulations producers of electrical equipment (generally manufacturers or importers) must register as such and have some obligations to take back their electrical equipment when it becomes waste.
The high-end electrical equipment used by data centres may be leased. Supply contracts may include upgrade or replacement equipment as necessary, including the management of any equipment which becomes waste.
Electrical equipment used in data centres may be repurposed elsewhere once it is no longer suitable for use in a data centre, or it may be recycled. The recycling industry for electrical equipment is well developed and regulated in the UK and has evolved to manage hazardous substances and Persistent Organic Pollutants (POPs).
Fuel and chemical storage
Fuels and chemicals likely to be stored at data centres may fall under the Control of Major Accident Hazards (COMAH) Regulations 2015 if the quantities stored exceed the thresholds identified in the regulations. A full list of dangerous substances and relevant threshold quantities can be found in Schedule 1 of the COMAH Regulations 2015, which is separated into Part 1 (generic categories) and Part 2 (named dangerous substances).
Where the COMAH qualifying quantity threshold for dangerous substances will be exceeded by the proposed development, the establishment will need to be regulated under the COMAH regime. Changes to quantities of substances stored on existing sites may result in a change of tier.
In either of these circumstances the operator is required to notify the Competent Authority, within a reasonable period of time (normally between 3 and 6 months) and prior to increasing the inventory stored at the establishment. Notification should be made to the competent authorities: the Health and Safety Executive and SEPA. Following notification, SEPA will expect the operator to submit an assessment of the environmental risks, demonstrating that All Measures Necessary have been undertaken in relation to the potential for major accidents to the environment.
To inform the assessment, it is recommended that sensitive environmental receptors within a 10km radius of the development are identified. Sensitive environmental receptors include statutory and local environmental designations, as well as local agricultural uses including livestock rearing.
See Scotland’s Environment Website COMAH search tool for guidance.
Please contact SEPA’s COMAH team at wasteandindustry@sepa.org.uk if the qualifying quantity threshold for dangerous substances are likely to be exceeded by the proposed development or if changes to stored substances on an existing site alters the site’s COMAH tier.