Under construction

Kao Data KLON-03

Harlow, United Kingdom

Reviewed 27 Sept 202613 sources

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Project brief

Third Harlow building with hybrid air/direct-to-chip cooling. JCA is linked to the phase; permit issue and the Q4 2026 target are recorded separately from unconfirmed operational handover.

Read overview

Current evidenceUnder construction

13 cited sources · 8 utility and planning categories reviewed.

Review evidence and gaps

Next check

Verify the demand agreement, campus import limit, KLON-03 allocation, network counterparty and energisation milestones independently of generator and IT ratings.

Open the full check

Overview

Third Harlow building with hybrid air/direct-to-chip cooling. JCA is linked to the phase; permit issue and the Q4 2026 target are recorded separately from unconfirmed operational handover.

Developer / applicant: Kao Data
Owner: Not verified
Operator: Kao Data

Planning and delivery status

Operator reported active construction on 18 August 2025; current Harlow page still labels KLON-03 under development. A 2026 ready-for-service target is not treated as confirmation of opening. HDR's March 2025 permit submission targeted Q4 2026 handover; the environmental variation issued 3 June 2026 does not confirm operational handover.

Stage source: 18 Aug 2025

Project intelligence. This record does not establish that the land or facility is available to acquire.

POWER STUDY

Power

What the power evidence establishes

The site-specific connection scope has not been established for this record.

Power classDNo qualifying rung

No same-scope, dated import-MVA rung has document-seen or better verification. Nearby infrastructure, IT MW and marketing claims cannot upgrade the class.

The class describes published documentary evidence at its stated date. It does not prove current contractual rights, transferability or an energisation date.

Class describes evidence maturity. Public records do not prove current contractual rights, transferable capacity or an energisation date. This record has not received a complete power study review.

Read the rules and verification levels

Capacity ladder and evidence

Each rung is a separate MVA claim for its stated site or phase. A missing rung is unknown.

Applied

Unknown

Not established from the public records reviewed.

What applied mva is evidenced for the assessed site scope?

Event date

Unknown

Not established from the public records reviewed.

What is the effective date of the applied connection evidence?

Capacity boundary

Unknown

Not established from the public records reviewed.

Which buildings or phases does the applied connection evidence cover?

Verification

Unknown

Offered

Unknown

Not established from the public records reviewed.

What offered mva is evidenced for the assessed site scope?

Event date

Unknown

Not established from the public records reviewed.

What is the effective date of the offered connection evidence?

Capacity boundary

Unknown

Not established from the public records reviewed.

Which buildings or phases does the offered connection evidence cover?

Verification

Unknown

Accepted / contracted

Unknown

Not established from the public records reviewed.

What accepted or contracted mva is evidenced for the assessed site scope?

Event date

Unknown

Not established from the public records reviewed.

What is the effective date of the accepted connection evidence?

Capacity boundary

Unknown

Not established from the public records reviewed.

Which buildings or phases does the accepted connection evidence cover?

Verification

Unknown

Energised

Unknown

Not established from the public records reviewed.

What energised mva is evidenced for the assessed site scope?

Event date

Unknown

Not established from the public records reviewed.

What is the effective date of the energised connection evidence?

Capacity boundary

Unknown

Not established from the public records reviewed.

Which buildings or phases does the energised connection evidence cover?

Verification

Unknown

Connection point and load boundaries

Network operator: Unknown
Not established from the public records reviewed.
Which TSO or DSO is responsible for this demand connection?
Connection point: Unknown
Not established from the public records reviewed.
What is the operator-confirmed connection substation or circuit?
Voltage: Unknown
Not established from the public records reviewed.
What voltage level is specified for the demand connection?
Straight-line distance: Unknown
Not established from the public records reviewed.
What are the evidenced site and connection-point coordinates, and their calculated straight-line distance?
Published route length: Unknown
Not established from the public records reviewed.
What grid route length is published, and for which circuit?

IT load

Unknown

Not established from the public records reviewed.

What is the published IT load in MW?

Basis

Unknown

Not established from the public records reviewed.

On what electrical basis is the IT load in MW stated?

Site / phase boundary

Unknown

Not established from the public records reviewed.

Which phase or campus does the IT load in MW cover?

Facility load

Unknown

Not established from the public records reviewed.

What is the published facility load in MW?

Basis

Unknown

Not established from the public records reviewed.

On what electrical basis is the facility load in MW stated?

Site / phase boundary

Unknown

Not established from the public records reviewed.

Which phase or campus does the facility load in MW cover?

Import capacity

Unknown

Not established from the public records reviewed.

What is the published import capacity in MVA?

Basis

Unknown

Not established from the public records reviewed.

On what electrical basis is the import capacity in MVA stated?

Site / phase boundary

Unknown

Not established from the public records reviewed.

Which phase or campus does the import capacity in MVA cover?

These are different electrical quantities. No power factor, PUE or available import is assumed from an IT-load statement.

Connection agreement and conditions

Agreement type: Unknown
Not established from the public records reviewed.
What connection agreement type and current status are documented?
Phased capacity: Unknown
Not established from the public records reviewed.
Does the agreement impose phased import-capacity limits?
Flexibility obligations: Unknown
Not established from the public records reviewed.
What flexibility or curtailment obligations apply?
On-site generation obligations: Unknown
Not established from the public records reviewed.
What on-site generation obligations apply?
Securities posted: Unknown
Not established from the public records reviewed.
What securities are required, posted and still valid?
Longstop dates: Unknown
Not established from the public records reviewed.
What connection longstop or milestone dates apply?

Conflicts and scope comparisons

No conflicting pair is recorded. This does not establish that all public statements have been reconciled.

United Kingdom grid context

Network publications frame the claim. They do not allocate capacity to this site.

No country context entries have been linked to this site. Applicable policy, capacity information and reinforcement dependencies need review.

Country coverage: prepared sources; site-level research not extended. View all country sources and refresh schedules.

Derived energisation window

Earliest plausible yearUnknown

Latest plausible yearUnknown

The observed inputs do not establish a bounded delivery range. Open bounds stay unknown.

Rule

Use only a same-scope, dated, document-verified capacity rung and an applicable duration to energisation published by the observed site operator. The named process operator and a named source publisher must match that operator. Earliest year is the maximum of stage date plus minimum duration and each evidenced readiness constraint. Latest year is the maximum of stage date plus maximum duration and each published upper constraint only when every required input is bounded. An offer-processing duration is excluded. A missing required input leaves the affected bound unknown; no padding or contractual delivery promise is inferred.

No observed inputs establish this result.

Dependencies driving the range

Connection-dependent reinforcement scope and completion dates: unknown.
Grid-works planning status and programme: unknown.
Applicable connection-policy conditions and programme: unknown.

What the earliest case requires

Connection-dependent reinforcement scope and completion dates introduces no later constraint than the earliest case; this remains unverified.
Grid-works planning status and programme introduces no later constraint than the earliest case; this remains unverified.
Applicable connection-policy conditions and programme introduces no later constraint than the earliest case; this remains unverified.

Missing inputs leave the range open

A dated, document-verified import-MVA rung for the assessed scope.
An applicable duration from the evidenced stage to energisation, published by and matched to the observed site operator, rather than an offer-processing target.
Connection-dependent reinforcement scope and completion dates
Grid-works planning status and programme
Applicable connection-policy conditions and programme

Indicative HV and connection capex

Unknown

Rule and scope

Sum each published complete scope quantity multiplied by the matching published benchmark minimum and maximum. Configuration, voltage, route type, unit, country applicability, currency and explicit price base year must match. No assumed route length, transformer count, exchange rate, inflation, fee uplift or partial index is inserted. The result is an indicative benchmark band, not an operator quotation or contractual connection charge.

No observed inputs establish this result.

Published connection works scope

Unknown

Not established from the public records reviewed.

What complete connection scope is published: bays, stations, voltage, circuits, route lengths and underground or overhead configuration?

Scope completeness

Unknown

Not established from the public records reviewed.

Is the published connection scope complete enough to match every component to a sourced benchmark?

Scope questions

Obtain a published complete connection scope with voltage, configuration and measured quantities.
Establish that every necessary connection-work component is included in the published scope.
Identify network and customer works, upstream reinforcement, land and wayleaves, taxes, fees, securities, contingency and the price base.

Country reference bands and sources

No eligible published capex reference has been recorded. Country bands remain unknown.

Alternatives and policy exposure

Behind-the-meter generation

Unknown

Not established from the public records reviewed.

What behind-the-meter generation is evidenced, and at what scope?

Planning / policy requirement

Unknown

Not established from the public records reviewed.

Does the applicable planning or connection policy require behind-the-meter generation?

Battery storage

Unknown

Not established from the public records reviewed.

What battery storage is evidenced, and at what scope?

Planning / policy requirement

Unknown

Not established from the public records reviewed.

Does the applicable planning or connection policy require battery storage?

Private wire

Unknown

Not established from the public records reviewed.

What a private wire is evidenced, and at what scope?

Planning / policy requirement

Unknown

Not established from the public records reviewed.

Does the applicable planning or connection policy require a private wire?

Gas

Unknown

Not established from the public records reviewed.

What gas supply or generation is evidenced, and at what scope?

Planning / policy requirement

Unknown

Not established from the public records reviewed.

Does the applicable planning or connection policy require gas supply or generation?

Connection claim against current policy

Unknown

Not established from the public records reviewed.

Does the published connection claim meet the policy applicable to its application date, location and agreement status?

Open questions for a Reality Check

Generated from unknown fields, missing derivation inputs and unresolved evidence. The questions identify the documents or specialist checks needed next.

60 questions to resolve

Which TSO or DSO is responsible for this demand connection?
Not established from the public records reviewed.
What is the operator-confirmed connection substation or circuit?
Not established from the public records reviewed.
What voltage level is specified for the demand connection?
Not established from the public records reviewed.
What are the evidenced site and connection-point coordinates, and their calculated straight-line distance?
Not established from the public records reviewed.
What grid route length is published, and for which circuit?
Not established from the public records reviewed.
What applied mva is evidenced for the assessed site scope?
Not established from the public records reviewed.
What is the effective date of the applied connection evidence?
Not established from the public records reviewed.
Which buildings or phases does the applied connection evidence cover?
Not established from the public records reviewed.
What evidence level can be supported for capacityLadder.applied?
Verification has not been established.
What offered mva is evidenced for the assessed site scope?
Not established from the public records reviewed.
What is the effective date of the offered connection evidence?
Not established from the public records reviewed.
Which buildings or phases does the offered connection evidence cover?
Not established from the public records reviewed.
What evidence level can be supported for capacityLadder.offered?
Verification has not been established.
What accepted or contracted mva is evidenced for the assessed site scope?
Not established from the public records reviewed.
What is the effective date of the accepted connection evidence?
Not established from the public records reviewed.
Which buildings or phases does the accepted connection evidence cover?
Not established from the public records reviewed.
What evidence level can be supported for capacityLadder.accepted?
Verification has not been established.
What energised mva is evidenced for the assessed site scope?
Not established from the public records reviewed.
What is the effective date of the energised connection evidence?
Not established from the public records reviewed.
Which buildings or phases does the energised connection evidence cover?
Not established from the public records reviewed.
What evidence level can be supported for capacityLadder.energised?
Verification has not been established.
What connection agreement type and current status are documented?
Not established from the public records reviewed.
Does the agreement impose phased import-capacity limits?
Not established from the public records reviewed.
What flexibility or curtailment obligations apply?
Not established from the public records reviewed.
What on-site generation obligations apply?
Not established from the public records reviewed.
What securities are required, posted and still valid?
Not established from the public records reviewed.
What connection longstop or milestone dates apply?
Not established from the public records reviewed.
What is the published IT load in MW?
Not established from the public records reviewed.
On what electrical basis is the IT load in MW stated?
Not established from the public records reviewed.
Which phase or campus does the IT load in MW cover?
Not established from the public records reviewed.
What is the published facility load in MW?
Not established from the public records reviewed.
On what electrical basis is the facility load in MW stated?
Not established from the public records reviewed.
Which phase or campus does the facility load in MW cover?
Not established from the public records reviewed.
What is the published import capacity in MVA?
Not established from the public records reviewed.
On what electrical basis is the import capacity in MVA stated?
Not established from the public records reviewed.
Which phase or campus does the import capacity in MVA cover?
Not established from the public records reviewed.
What operator-published connection-to-energisation duration applies to this site and connection stage?
An application-to-offer processing target is not an energisation duration.
Which reinforcements does the connection depend on, and what dates are published?
Not established from the public records reviewed.
Which grid works require planning, and what is their current consent status and dated programme?
Not established from the public records reviewed.
Which connection-policy conditions apply, and when could they be satisfied?
Not established from the public records reviewed.
What complete connection scope is published: bays, stations, voltage, circuits, route lengths and underground or overhead configuration?
Not established from the public records reviewed.
Is the published connection scope complete enough to match every component to a sourced benchmark?
Not established from the public records reviewed.
What behind-the-meter generation is evidenced, and at what scope?
Not established from the public records reviewed.
Does the applicable planning or connection policy require behind-the-meter generation?
Not established from the public records reviewed.
What battery storage is evidenced, and at what scope?
Not established from the public records reviewed.
Does the applicable planning or connection policy require battery storage?
Not established from the public records reviewed.
What a private wire is evidenced, and at what scope?
Not established from the public records reviewed.
Does the applicable planning or connection policy require a private wire?
Not established from the public records reviewed.
What gas supply or generation is evidenced, and at what scope?
Not established from the public records reviewed.
Does the applicable planning or connection policy require gas supply or generation?
Not established from the public records reviewed.
Does the published connection claim meet the policy applicable to its application date, location and agreement status?
Not established from the public records reviewed.
Which checked country-grid sources and location-specific constraints apply to this connection?
No country-context relationship has been established for this record.
Identify network and customer works, upstream reinforcement, land and wayleaves, taxes, fees, securities, contingency and the price base.
Connection-cost scope question.
Resolve the energisation input: A dated, document-verified import-MVA rung for the assessed scope.
This missing input leaves an energisation bound unknown.
Resolve the energisation input: An applicable duration from the evidenced stage to energisation, published by and matched to the observed site operator, rather than an offer-processing target.
This missing input leaves an energisation bound unknown.
Resolve the energisation input: Connection-dependent reinforcement scope and completion dates
This missing input leaves an energisation bound unknown.
Resolve the energisation input: Grid-works planning status and programme
This missing input leaves an energisation bound unknown.
Resolve the energisation input: Applicable connection-policy conditions and programme
This missing input leaves an energisation bound unknown.
Obtain a published complete connection scope with voltage, configuration and measured quantities.
This scope or reference gap prevents a complete indicative connection capex band.
Establish that every necessary connection-work component is included in the published scope.
This scope or reference gap prevents a complete indicative connection capex band.

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Earlier capacity notes and source context

17.6 MW ITProject capacity

KLON-03 planned hybrid-cooled IT capacity. Not secured utility MVA.

Published claimProject source record

Import rights and connection evidence

The March 2025 HDR permit submission identifies the campus London Road customer substation and three 33 kV A/B/C feeds from Harlow West; redundant A/B full-load capability must not be summed. KLON-03's 17.6 MW is a planned IT rating. Neither the permit nor operator announcement establishes a separate building import entitlement, spare campus allocation or connection transferability.

IT load, facility demand, import capacity and equipment ratings retain their stated scope. A published figure does not establish spare or transferable supply.

Planning & utilities

8 of 10 categories contain evidence. Each status applies to its specific claim.

Grid & import rights

Partial evidence

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Verify the demand agreement, campus import limit, KLON-03 allocation, network counterparty and energisation milestones independently of generator and IT ratings.

HDR: Harlow permit variation non-technical summary submitted to the Environment AgencySource: 31 Mar 2025
Kao Data: KLON-03 hybrid liquid cooling design and programmeSource: 12 Mar 2025

Fibre & dark fibre

Partial evidence

Zayo's 2023 lit/dark-fibre arrangement and euNetworks' Cambridge research link identify real campus carriers. Zayo located its two announced points of presence at KLON-01; neither release confirms KLON-03 entry ducts, physically separate routes or current service delivery at the new building.

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Obtain KLON-03 carrier and entrance schedules, route-diversity drawings and current dark-fibre availability; verify commissioning rather than carrying the campus announcement to the building.

Zayo: Harlow lit and dark-fibre agreement and KLON-01 points of presenceSource: 26 Jun 2023
euNetworks: Cambridge research network and direct fibre to Harlow campusSource: 11 Jan 2021

Ownership & development control

Partial evidence

The issued June 2026 environmental variation names Harlow Operations Limited and incorporates KLON-03 regulated standby-generation activities. It confirms a regulatory operating entity, not land title, the lease route or a third party's ability to control development. No property owner is inferred from Kao's operating brand.

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Reconcile the permitted area with registered titles, development agreements and rights to shared campus access, fibre and electrical infrastructure.

Environment Agency: EPR/WE4588AB/V002 variation and consolidated permitSource: 3 Jun 2026

Land, footprint & access

Partial evidence

The current operator page places KLON-03 in the existing 15-acre Harlow campus and identifies it as a 17.6 MW building under development. Whole-campus area is not the KLON-03 plot area, available expansion land or a separately marketable parcel.

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Inspect the approved KLON-03 red line and layout for footprint, service yards, construction logistics, fire access and easements; establish which areas remain available after later phases.

Kao Data: current Harlow building capacities and campus specificationSource: Publication date unstated

Flood, ground & environment

Partial evidence

The June 2026 permit variation adds 11 KLON-03 standby generators with SCR and associated surface-water/oil-interceptor controls. HDR's March 2025 site-condition submission reports sampled contaminants below its generic assessment criteria, negative asbestos results and no groundwater exceedances requiring further investigation. The regulator separately accepted incomplete historic baseline information with implications at surrender; the sampling report is not an unrestricted clean-site certificate.

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Verify implementation and acceptance of air-quality improvement requirements, generator commissioning tests, drainage controls and remaining ground/flood conditions; retain the distinction between sampled results and the regulator's baseline caveat.

Environment Agency: EPR/WE4588AB/V002 variation and consolidated permitSource: 3 Jun 2026
HDR: Harlow site condition report submitted to the Environment AgencySource: 31 Mar 2025
Environment Agency: EPR/WE4588AB/V002 decision documentSource: 3 Jun 2026

Water, cooling & heat

Partial evidence

Kao's March 2025 design describes hybrid air and direct-to-chip liquid cooling within the same technology suite, supporting rack densities up to 130 kW. This is a planned KLON-03 capability, not proof of every rack configuration, installed liquid-cooling coverage, measured water performance or a contracted heat reuse scheme.

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Verify installed CDU/loop scope, water and discharge rights, peak demand, actual rack envelopes, commissioning and any heat-offtake agreement.

Kao Data: KLON-03 hybrid liquid cooling design and programmeSource: 12 Mar 2025

Demand & location fit

Partial evidence

Kao positions KLON-03 for AI training/inference close to London exchange and cloud connectivity. The announcement also discusses Ori on the Harlow campus; it does not establish a named KLON-03 tenancy, occupied MW or a specific customer commitment to this phase.

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Seek a phase-specific customer or lease announcement and commissioned occupied capacity; do not move campus-level AI customers automatically into KLON-03.

Kao Data: KLON-03 hybrid liquid cooling design and programmeSource: 12 Mar 2025

Programme & delivery

Partial evidence

Maple Facades names JCA Engineering as KLON-03 contractor and Marchini Curran as architect. HDR's March 2025 submission targeted Q4 2026 handover; the current Harlow page still says under development. The generator variation issued 3 June 2026 is a regulatory milestone, not operational handover. Existing dated evidence of construction is retained.

Sources & next check

Evidence reviewed 27 Sept 2026

Next check

Obtain a dated construction/handover update, commissioning status, actual energisation and phase availability; confirm JCA's full contracted scope and any change to the Q4 2026 target.

Maple Facades: KLON-03 architect and contractorSource: Publication date unstated
HDR: Harlow permit variation non-technical summary submitted to the Environment AgencySource: 31 Mar 2025
Kao Data: current Harlow building capacities and campus specificationSource: Publication date unstated
Environment Agency: Harlow permit variation issuedSource: 3 Jun 2026

Not assessed

Planning & decisionsLand-use zoning

Evidence still needed

Planning & decisions
A current planning decision, conditions and any appeal or court proceedings still need to be checked.
Land-use zoning
The site boundary has not been matched to the current adopted zoning map and data-centre use policy.

Project team

Appointments are limited to the project, phase and scope supported by each source.

Main contractor

JCA EngineeringOther projects

KLON-03 contractor named in Maple Facades' building-specific case study.

Appointment source

Architect

Marchini Curran AssociatesOther projects

KLON-03 architecture and wider campus masterplan; architect reports construction started January 2024.

Appointment source

Engineering consultant

MEIT ConsultantsOther projects

Published campus MEP design scope includes planned KLON-03 and KLON-04; specific later construction-stage scope not established.

Appointment source

HDROther projects

2025 Harlow environmental-permit variation submission including KLON-03 standby generation; not evidence of a general MEP delivery appointment.

Appointment source

Unlisted roles have no project-specific appointment recorded.

Sources

Publication dates are shown where known. Review dates do not establish approval or commissioning.

Original documents and maps retain their rights. Public access does not grant commercial redistribution rights.