2.6% of the sites, 12.3% of the energy: data centres in the UK’s Climate Change Agreements scheme Published dataset: cca-data-centres-energy-share-2026.csv Study page: https://www.servnetuk.com/research/cca-data-centres-energy-share-2026 WHAT THIS IS One row per facility certified under the Climate Change Agreements scheme for certification period 7, as published by the Environment Agency in its Reduced Rate Certificates register. n = 8,285. This is a census of the published register, not a sample. Each row carries the figures needed to recompute every headline on the study page: the facility share, the energy share, the intensity ratio and both rankings. Every figure comes from one of two Environment Agency files under the Open Government Licence v3.0. Nothing was measured, inspected, surveyed or estimated by us, and no one was contacted. No individual is named anywhere in this file and no facility address is carried for any sector. THE ONE THING TO GET RIGHT 214 is a count of facilities certified under one voluntary tax-discount scheme. It is not a count of data centres in the UK, and it cannot be combined with any other data centre count. The scheme is voluntary, entry runs through a sector association, the eligible activity is the leasing or licensing of a data facility used as a data centre, and the scheme was closed to new entrant facilities from 1 November 2018 until a window that closed on 30 September 2025 — though it is open again, with an application window running from 1 January to 31 August in each of 2026 to 2029 under the February 2026 statutory guidance. Certification is not a pass mark either: an operator that misses its target may pay a buy-out fee and stay certified, and 54.5 per cent of target units missed their target period 6 target. DATA AS AT Computed 2026-09-25 from two Environment Agency workbooks downloaded 2026-09-25T09:06Z and mirrored with their hashes. Facility counts are the certification period 7 register (published under a landing page dated 18 September 2026; the file itself was generated 31 August 2026). Energy is target period 6, the calendar year 2024. No network access at analysis time. HEADLINE FIGURES, WITH THEIR DENOMINATORS - Data centres as a share of certified facilities: 2.58% 214 facilities. 214 is a count of facilities carrying the sector name 'Data Centres' in the Environment Agency's Reduced Rate Certificates register for certification period 7. It is a count of members of one voluntary tax-discount scheme. It is not a count of data centres in the UK, and it cannot be combined with any other data centre count. Denominator: the 8,285 facilities on the CP7 Reduced Rate Certificates register, published 18 September 2026 - Data centres as a share of the energy the scheme reported: 12.29% 12,327.58 GWh of 100,323.47 GWh, for target period 6, which ran for the calendar year 2024. Nine of the 55 sector rows carry no energy figure, so this is a share of reported energy, not of the scheme's whole energy. Denominator: the 100,323.47 GWh of target-period energy reported across the 46 TP6 sectors that carry a figure - Energy share against facility share: 4.76 times 12.29 per cent of reported energy against 2.58 per cent of facilities. On the same measure data centres rank 9th of 45 sectors, so this is a large sector with high intensity, not the scheme's most disproportionate one. Denominator: the facility share, 2.583 per cent - Rank by reported TP6 energy: 2nd of 46 Behind Food and Drink at 20,426.67 GWh and ahead of Chemicals at 10,141.42 GWh. Denominator: the 46 TP6 sectors that carry a target-period energy figure - Rank by facility count: 8th of 49 Behind Supermarkets (2,032), Bakers (1,796), Food and Drink (751), Poultry Meat Rearing (549), Plastics (447), Cold Storage (414) and Printing (285). Denominator: the 49 sectors on the CP7 register - Reported energy per certified data centre: 57.6 GWh Against a scheme mean of 12.1 GWh per certified facility. TP6 is a 12-month period, so these are annual figures. 0.80 GWh per craft bakery and 0.25 GWh per supermarket food-processing facility. Denominator: 214 certified data centre facilities against 8,285 certified facilities - Distinct operators behind the 214 facilities: between 60 and 87 87, 82, 82, 78 and 60 under five normalisation rules published side by side; top-ten concentration moves from 44.4 to 60.3 per cent across the same five. The register files some operators one company per data hall and carries several operator names under more than one spelling, one of them under three, so no single count is defensible. Denominator: the 214 certified data centre facilities COLUMNS facility_id: The facility identifier exactly as published. Prefixed with the sector association code. Unique within this certification period only; not a stable key across periods. sector_register: Sector name exactly as it appears on the register's Data sheet. 49 distinct values. sector_code: Sector association code, derived from the facility identifier prefix. Not a column in the source file. sector_association: Sector association as listed on the register's Details sheet. The Details sheet spells two sectors the way the performance workbook does rather than the way the register's own Data sheet does, so the crosswalk's rename map is applied to this lookup. Empty only for Silica Sand (8 rows), which the Details sheet does not list at all. performance_sector_rows: The sector row or rows in the TP6 performance workbook that this register sector maps to, through the published crosswalk. Sawmills maps to two. crosswalk_relationship: exact match, renamed, or sub-sector split. is_data_centre: true for the 214 rows in the Data Centres sector. operator_as_published: Operator name exactly as published, but only where the string carries a registered-company or public-body token. Otherwise empty. See operator_withheld_reason. operator_withheld_reason: Why an operator name is empty. The register publishes a name on every row; in the farming sectors it can be an individual's, so we withhold anything that does not clearly name a body corporate. operator_L2_case_whitespace: Normalisation rule 2: case-folded, whitespace collapsed. operator_L3_punctuation: Rule 3: rule 2 plus punctuation removed and the ampersand written out. operator_L4_legal_suffix: Rule 4: rule 3 with trailing legal and structural suffixes stripped. operator_L5_leading_token: Rule 5: rule 4 reduced to its first word. Knowingly over-merges; an upper bound on concentration, not an estimate. facility_address_published: false where the Environment Agency withholds the address. No address is carried in this file for any sector. address_withholding_reason: The publisher's stated reason, where an address is withheld. sector_facilities_cp7: Number of certified facilities in this sector. A sector attribute, repeated on every row of the sector. sector_facility_share_pct: That count as a percentage of all 8,285 certified facilities. sector_small_n: true where the sector has fewer than ten certified facilities. Percentages on those sectors are not reliable and no claim in the study rests on one. sector_tp6_energy_gwh: Target-period-6 energy reported for this sector, in GWh, at full stored precision. Empty for the four sectors whose energy the Environment Agency withholds. A sector attribute, not a facility attribute: summing it down this column will give the wrong total. sector_energy_reported: false for Cement, Egg Processing, Kaolin and Ball Clay and Tyres. sector_energy_share_of_reported_pct: Sector energy as a percentage of the 100,323.471 GWh reported for TP6. In this file that total sits on 45 register sectors; it is 46 rows in the TP6 workbook before the crosswalk, because the workbook's two Sawmills rows are one sector on the register. The GWh are the same either way. Not a percentage of the scheme's whole energy. sector_gwh_per_facility: Sector energy divided by the sector's certified facility count. Annual, because TP6 is a twelve-month period. sector_intensity_ratio: GWh per facility divided by the scheme mean of 12.109 GWh per certified facility. Equivalently, energy share divided by facility share. sector_energy_rank_of_45_by_intensity: Rank on that ratio among the 45 register sectors that carry TP6 energy. Data Centres is 9th. METHOD Two Environment Agency files were mirrored with their hashes and joined. Facility counts come from the Reduced Rate Certificates register for certification period 7, published under regulations 9(1) and 9(2) of the Climate Change Agreements (Administration) Regulations 2012. Reported energy comes from the Sector Performance Data workbook for target period 6. The publisher does not join these two files. Both are censuses of what is published, not samples. 1. Mirror both workbooks. Check byte count, md5 and sha256 against the values recorded before download. A mismatch stops the run. 2. Parse both workbooks with a reader that matches element names on their local name only, because the two files declare different SpreadsheetML namespaces. 3. Assert the register shape: 8,285 facility rows, 0 duplicate identifiers, 49 sectors, 214 of them data centres. 4. Assert the performance shape: 55 TP6 sector rows, 46 carrying energy, totalling 100,323.471 GWh. 5. Apply the pre-registered sector crosswalk, which is the only hand-authored content in the analysis. Assert that no register sector is unmatched and no GWh is lost to the join. 6. Compute facility share against the 8,285 register rows and energy share against the 100,323.471 GWh of reported TP6 energy, carrying full precision and rounding once at presentation. 7. Compute the intensity ratio, both rankings, energy per facility, and the Bakers and Supermarkets comparison. 8. Compute distinct operators for the 214 data centre facilities under five normalisation rules and publish all five. 9. Screen every operator string for personal data and withhold any that carries no corporate or public-body token. 10. Write the published dataset, the page JSON and the README. Nothing is fetched at this stage. LIMITS - 214 is a count of facilities certified under one voluntary scheme, not a count of data centres in the UK. It must not be multiplied by, netted against, or compared with any external data centre count. - The two halves of the headline pair are measured at different dates. The facility share is over the 8,285 facilities certified for certification period 7, in a register file generated on 31 August 2026 and published under a landing page dated 18 September 2026. The energy share is over target period 6, which ran from 1 January 2024 to 31 December 2024, when the Environment Agency's biennial report records 3,332 target units covering 8,685 facilities in the scheme. Each share is internally consistent within its own file. They are not two cuts of one population, and this is the weakest joint in the metric. - 100,323.47 GWh is the energy the scheme reported, not the scheme's whole energy. Nine of the 55 TP6 sector rows carry no energy figure. Five of those nine are blank throughout and have no CP7 register counterpart. The other four — Cement, Egg Processing, Kaolin and Ball Clay and Tyres, 20 certified facilities between them — report emissions but not energy. The Environment Agency does not say why those four in particular are blank; it states a general rule, that it “deliberately excluded energy consumption data for sectors with fewer than 3 distinct operators to avoid disclosure of commercially sensitive information”, and the attribution of the four blanks to that rule is ours, not the publisher's. Note that five further sector rows are blank for energy and are not attributed to it. Those four sectors are 1.30 per cent of reported TP6 emissions, so the effect on the data centre share is small, and it runs downwards: the true all-scheme share would be slightly below 12.29 per cent. - Those 20 facilities count in the facility denominator but contribute nothing to the energy denominator, so the two denominators are not perfectly coextensive. They are 0.24 per cent of the register. - The energy figures cover only energy subject to a Climate Change Agreement. In the Environment Agency's words, the report “only covers the energy use that is subject to a CCA, which may not be all the energy used in facilities (for example, fuels used by those regulated by the UK Emission Trading Scheme, UK ETS, are excluded)”. These are not site totals. - Target period 6 is a twelve-month period covering calendar 2024, so 100,323.47 GWh and 12,327.58 GWh are annual figures, and 57.6 GWh per certified data centre is an annual figure. - Data centres rank 9th of 45 on energy per certified facility. The 4.76 ratio is a real and large gap, but the sector is not the most disproportionate in the scheme and the study should not be read as saying so. - The two workbooks name their sectors differently, so the join runs through a hand-built crosswalk published with this study: 42 exact matches, 8 renamed or split, 5 performance sectors with no CP7 counterpart. Data Centres, Bakers and Supermarkets each match one-to-one on an exact string, so no headline figure depends on a crosswalk judgement. - The scheme's Bakers sector is craft baking, defined against ‘industrial’ baking, and its Supermarkets sector is food processing inside supermarket stores, not a supermarket's electricity. The bakery comparison is meaningless without those definitions and they are carried with it wherever it appears. - Distinct-operator counts for the 214 facilities range from 60 to 87 across five rules and top-ten concentration from 44.4 to 60.3 per cent. The range is the finding. No single operator count is published, and no operator figure appears in the headline. - The register publishes an operator name for every facility. In the farming sectors that name can be an individual's. The published dataset carries an operator name only where the string contains a registered-company or public-body token; 236 of 8,285 rows are withheld by that screen, and all 214 data centre rows pass it. The screen is ours, is deliberately strict, and is reproducible from the published dataset: the rows it withholds are the rows where operator_as_published is empty. - Facility addresses are withheld by the publisher for six sectors — Data Centres, Eggs and Poultry Meat, Meat, Pigs, Poultry Meat Processing and Poultry Meat Rearing — for reasons of national security and site security. That is 1,148 facilities, including all 214 data centres. No address of any kind is carried into the published dataset, for any sector. - Both source files are overwritten at the same URL every month with no archive and no version history. From the next Environment Agency refresh, the live URLs will not reproduce these figures. The byte counts, md5 and sha256 of the exact files used are published in the source list; the exact files themselves are republished with this study under the Open Government Licence v3.0, so the whole analysis stays checkable after the sources have moved on; and the analysis script refuses to run against different bytes. - The register's own internal timestamp decodes to 31 August 2026, while the data.gov.uk landing page says the dataset was updated on 18 September 2026. The latest certification start date anywhere in the file is 26 August 2026, which is consistent with a file generated on 31 August. Both dates are real and mean different things; the file used here was generated on 31 August 2026 and published on the landing page dated 18 September 2026. - Four official sources give four different sector counts for the same scheme: 49 sector names on the register's Data sheet, 48 sector associations on its Details sheet, 55 sector rows on the TP6 sheet and 53 claimed on the sector performance landing page. Each figure here names which of those it uses. - The sector performance landing page is stale against its own data: it still describes a scheme running to 31 March 2025 and “four biennial target periods between 2013 and 2020”. It is not used for sector counts or scheme dates. - Percentages on fewer than ten facilities are marked in the published dataset. Thirteen of the 49 register sectors have fewer than ten certified facilities, one of them a single facility. No claim here rests on any of them. - The workbook states that energy and emissions were “rounded down to 2 decimal places for presentation purposes”, but the stored cells carry full precision and are used as stored. Every figure is rounded once, at presentation. - The data centre sector is recorded as meeting its target period 6 target while reporting more absolute energy than in its base year, because the target is an efficiency measure adjusted for membership change while the energy columns are not. The two figures are not comparable, neither is set against the other anywhere in this study, and no growth in data centre energy use is measured or claimed here. - Two prior-art sources could not be checked. The House of Commons Library briefing on data centres and the Environmental Audit Committee's written evidence both sit behind a challenge that returned an error to our identifying user agent; we stopped rather than working around it. The Commons Library is the most likely place a competing UK figure would appear, so the prior-art sweep has a known hole there. The finding is worded as what we found, not as what exists. - Certification is not a pass mark. An operator that misses its target may pay a buy-out fee — £25 for each tonne of CO2e above target emissions in target period 6 — and stay certified: the Environment Agency records 1,766 target units, 54.5 per cent, failing their TP6 target. The 8,285 facilities counted here are facilities certified for the discount, not facilities that met an efficiency target. - The scheme covers the whole of the UK, not Great Britain: the Environment Agency administers it UK-wide on behalf of the Department for Energy Security and Net Zero, and 177 of the 8,285 certified facilities carry Northern Ireland postcodes. None of the 177 is a data centre facility, for a mechanical reason rather than a geographic one: data centre rows carry a placeholder in place of an address, so they cannot appear in a postcode-derived count at all. The register does not say where the 214 are. WHERE SOURCES DISAGREE - When certification period 7 ends data.gov.uk, Reduced Rate Certificates landing page: 1 July 2025 to 30 June 2027 Environment Agency, biennial progress report for 2023 and 2024, section 3.1: introduced on 1 July 2025 and running until 31 March 2027 Department for Energy Security and Net Zero, Climate Change Agreements: statutory guidance 2026, updated 24 February 2026: “Certification Period 7, which has been extended to 30 June 2027” What we do: We report all three. The 2026 statutory guidance is the latest of them and is consistent with the landing page, so the population is described as certification period 7, 1 July 2025 to 30 June 2027, with the biennial report's earlier end date recorded. No figure in this study depends on the end date. - When the register was published data.gov.uk landing page: Updated 18 September 2026 The workbook's own Details sheet, cell B2, Excel serial 46265.895: 31 August 2026, 21:28 UTC data.gov.uk landing page, dataset reference date (revision): 31 August 2026 What we do: Both are recorded. The file was generated on 31 August 2026 and appears under a landing page dated 18 September 2026. Nothing here is dated to 18 September alone. - How many sectors the scheme has RRC register, Data sheet: 49 distinct sector names RRC register, Details sheet: 48 sector associations, with two sectors spelled differently from the Data sheet and one, Silica Sand, absent Sector Performance Data workbook, TP6 sheet: 55 sector rows, 46 of them carrying energy data.gov.uk sector performance landing page: 53 industrial sectors Environment Agency biennial report: 50 active sectors and sub-sectors What we do: Every count in this study names the file it comes from. The crosswalk between the register's 49 and the workbook's 55 is published in full so the join can be checked line by line. - How many data centre sites are in the scheme techUK, Climate Change Agreements for data centres page, dated 14 November 2023, live 25 September 2026: “Over 170 data centre sites currently participate in the scheme.” This study, from the CP7 register: 214 certified facilities carrying the sector name Data Centres What we do: These are not in conflict, and neither can be checked against the other. techUK counts “sites” that “participate” on a page dated 14 November 2023, without defining a site or giving an as-at date for the figure; we count rows on the certification register at a stated date. The two are not the same quantity, and neither corrects the other. - How many facilities are in the scheme RRC register, certification period 7: 8,285 certified facilities Environment Agency biennial report, at the end of TP6: 3,332 target units covering 8,685 facilities Environment Agency biennial report, section 4.3: 6,656 facilities certified at the start of the certification period What we do: These are different bases at different dates — certified against in-scheme, and a register that is revised monthly against a snapshot. They are reported side by side and never subtracted from one another. The biennial report also names the period in that third figure as CP6, which conflicts with its own section 3.1; we flag it and do not rely on it. SOURCES - Climate Change Agreements: Reduced Rate Certificates (RRC), certification period 7 Publisher: Environment Agency File: https://environment.data.gov.uk/api/file/download?fileDataSetId=671c16da-9129-4a65-a99c-85acd58350f1&fileName=Climate_Change_Agreements_-_Reduced_Rate_Certificates_(RRC).xlsx Landing page: https://www.data.gov.uk/dataset/791f5d8b-ac3b-4669-9e7b-e269ae634f94/climate-change-agreements-reduced-rate-certificates-rrc 549952 bytes, md5 3d6832c081de879062e2fb482d618106 sha256 5fc40640e262c234ac18b222ee0b88c04c0eb3854a3efeedc205edfa756e9bcb Retrieved: 2026-09-25T09:06:12Z Licence: Open Government Licence v3.0 Note: Overwritten at the same URL on the last working day of each month. No archive, no version history. - Climate Change Agreements: Sector Performance Data (TP1 to TP6) Publisher: Environment Agency File: https://environment.data.gov.uk/api/file/download?fileDataSetId=a7ba7185-f9ea-46ac-a661-fb27cfa8f5dc&fileName=Climate_Change_Agreements_-_Sector_Performance_Data.xlsx Landing page: https://www.data.gov.uk/dataset/f98a442f-32c8-4c0a-8c1e-e0576b283b89/climate-change-agreements-sector-performance-data 65086 bytes, md5 3a66e1102eb8ac67faad2df3032dfa6a sha256 5d2f6639e7aa1c611e360afd3ceb9b88eb083092fb9007714c42369ae7af40d0 Retrieved: 2026-09-25T09:06:19Z Licence: Open Government Licence v3.0 Note: Overwritten at the same URL monthly. No archive. - Climate Change Agreements biennial progress report for 2023 and 2024 Publisher: Environment Agency Landing page: https://www.gov.uk/government/publications/climate-change-agreements-cca-biennial-report/climate-change-agreements-biennial-progress-report-for-2023-and-2024 Retrieved: 2026-09-25T09:11Z Licence: Open Government Licence v3.0 - Climate Change Agreements Operations Manual, February 2022 (LIT7911), Appendix A: Eligible processes Publisher: Environment Agency File: https://assets.publishing.service.gov.uk/media/6216220cd3bf7f4f0399d084/Climate-Change-Agreements-Operations-Manual.pdf Landing page: https://www.gov.uk/government/publications/climate-change-agreements-operations-manual--2 Retrieved: 2026-09-25 Licence: Open Government Licence v3.0 - Climate Change Levy rates (guidance) Publisher: HM Revenue and Customs Landing page: https://www.gov.uk/guidance/climate-change-levy-rates Retrieved: 2026-09-25T09:10Z Licence: Open Government Licence v3.0 - The Climate Change Agreements (Administration) Regulations 2012 (SI 2012/1976), regulation 9 Publisher: The National Archives / legislation.gov.uk Landing page: https://www.legislation.gov.uk/uksi/2012/1976/regulation/9/made Retrieved: 2026-09-25 Licence: Open Government Licence v3.0 - Climate Change Agreements: statutory guidance 2026 (accessible webpage) Publisher: Department for Energy Security and Net Zero Landing page: https://www.gov.uk/government/publications/climate-change-agreements-statutory-guidance/climate-change-agreements-statutory-guidance-2026-accessible-webpage 120988 bytes, md5 1f8c1a404e72f9054dab077354aa847d sha256 329607b21c96665d495b218d68b35b44ed779a104079ad7c85b379284220d5ca Retrieved: 2026-09-25T10:42Z Licence: Open Government Licence v3.0 - Climate Change Agreements (CCA) for data centres Publisher: techUK Landing page: https://www.techuk.org/resource/climate-change-agreements-cca-for-data-centres.html Retrieved: 2026-09-25T09:11Z Licence: techUK copyright. Not open-licensed. Mirrored for verification only; one short sentence quoted with attribution as prior work. No data from this page is republished. LICENCE AND ATTRIBUTION Source data: Open Government Licence v3.0. Contains public sector information licensed under the Open Government Licence v3.0. (c) Environment Agency copyright and/or database right. The register states 2016 and the sector performance workbook states 2017; both are reproduced as published. This derived dataset: Creative Commons Attribution 4.0 International (CC BY 4.0), https://creativecommons.org/licenses/by/4.0/. Please attribute as: Servnet, "2.6% of the sites, 12.3% of the energy: data centres in the UK’s Climate Change Agreements scheme", https://www.servnetuk.com/research/cca-data-centres-energy-share-2026. One source cited in the study, techUK's Climate Change Agreements page, is not open-licensed. It is cited as prior work with a single short quotation and none of its content is reproduced in this dataset. THE SOURCE FILES THEMSELVES Both Environment Agency workbooks are overwritten at the same URL every month with no archive, so the exact bytes this study was computed from are republished beside it under the Open Government Licence v3.0. Re-running the analysis against these copies reproduces every figure after the live URLs have moved on. - /research/cca-data-centres-energy-share-2026-source-rrc-cp7.xlsx Climate Change Agreements: Reduced Rate Certificates (RRC), certification period 7, exactly as downloaded on 25 September 2026 549952 bytes, md5 3d6832c081de879062e2fb482d618106 sha256 5fc40640e262c234ac18b222ee0b88c04c0eb3854a3efeedc205edfa756e9bcb Licence: Open Government Licence v3.0. © Environment Agency copyright and/or database right 2016. All rights reserved. - /research/cca-data-centres-energy-share-2026-source-sector-performance-tp1-tp6.xlsx Climate Change Agreements: Sector Performance Data (TP1 to TP6), exactly as downloaded on 25 September 2026 65086 bytes, md5 3a66e1102eb8ac67faad2df3032dfa6a sha256 5d2f6639e7aa1c611e360afd3ceb9b88eb083092fb9007714c42369ae7af40d0 Licence: Open Government Licence v3.0. © Environment Agency copyright and/or database right 2017. All rights reserved. REPRODUCING THIS FILE Everything is recomputable from the two mirrored workbooks alone. Re-download both from the source URLs and check the byte counts and hashes in the source list first: the Environment Agency overwrites both files monthly at the same URL with no archive, so a later copy will not reproduce these figures and a hash mismatch is expected after the next refresh. Every figure below can then be recomputed from the published CSV alone, with the recipe given against it; the two rankings and the crosswalk can be rebuilt from the mirrored workbooks the same way. The analysis script is not published with this dataset, and nothing here depends on it. Every headline figure carries a recompute recipe in the study JSON at /research/cca-data-centres-energy-share-2026/data.json, and each recipe runs on this CSV or on the two mirrored workbooks with no code of ours.