OSS topsides, jackets and auxiliaries
Completions software for the platform that every turbine in the array depends on.
An offshore substation is a small process platform with switchgear instead of separators: transformers, GIS, protection, auxiliary power, HVAC, fire and gas and marine systems. It is commissioned like a topsides scope and it gates the entire wind farm.
- Scope
- Topsides plus jacket
- Core systems
- HV, LV, auxiliaries, safety
- Evidence
- FAT, SAT, protection tests
- Gate
- Back-energisation from shore
Choose your project type
The problem
The platform is on the critical path, and half its evidence arrives from vendors.
Nothing in the array can be energised until the substation is. Yet a large share of the gating documentation — transformer FAT, GIS routine tests, protection relay configuration, fire and gas certification — is produced by suppliers in their own formats.
Those documents typically land as PDFs in a transmittal folder with no link to the equipment they qualify, so proving that a specific bay is fully evidenced becomes a document control exercise.
Deskely files third-party documents under the tag they belong to, and treats them as prerequisites the certificate above cannot ignore.
Setting up the register
A substation is a set of subsystems, not one large asset.
HV bays, transformer, earthing, LV distribution, UPS, diesel generator, HVAC, fire and gas, navigation aids and marine systems each behave as their own subsystem with their own completion path.
Single line diagrams and cable schedules are parsed into the register so every bay, panel and cable carries its drawing reference.
That breakdown is what makes partial energisation possible: auxiliaries can be live and proven while the HV scope is still being tested.
Energisation gating
Back-energisation is a gate, and the gate is the records.
Before the export cable brings power out to the platform, the grid operator and the owner both expect a demonstrable set: protection settings verified, interlocks proven, earthing tested, safety systems functional and no Category A punch open on the affected subsystems.
Deskely blocks the energisation certificate while any of those prerequisites are unsigned, and shows exactly what is outstanding rather than a percentage.
Once issued, the certificate lists what permitted it, which is the form the transmission owner's audit takes.
Handover and audit
The transmission owner inherits the platform, and inherits the evidence with it.
In many markets the substation transfers to a transmission owner or an OFTO after commissioning, and the transfer is priced on how complete and retrievable the documentation is.
Because certificates are issued from records rather than alongside them, the dossier exists continuously. Pick any bay, see the FAT, the SAT, the protection test, the punch position and who signed each.
That is the difference between a due diligence exercise that takes weeks and one that takes an afternoon.
High voltage safety documentation
Energising an offshore substation is a safety act, so the switching, permit and earthing records matter as much as the test results.
Before the first backfeed, a substation needs an approved switching schedule, authorised persons nominated in writing, permits to work raised and cancelled in sequence, earths applied and removed against a register, and locks and keys accounted for on a board that somebody signs.
This is documentation the transmission owner and the operator's HV authority will both audit, and it is generated during exactly the period when the platform is busiest and least connected.
Keeping the switching schedule, permit register and earthing records against the same tags as the test evidence means the authorised person can see, at the point of switching, that the equipment in front of them is proven, unpunched and safe to make live.
How it runs
From vendor FAT to a platform ready to back-energise.
Substation scopes are documentation-heavy and vendor-dependent. The system has to hold third-party evidence as first-class records, not attachments nobody can find.
- 01
Break the platform into subsystems
HV bays, transformer, earthing, LV, UPS, HVAC, F&G, marine and navigation aids as separate completion paths.
- 02
Draft the register from SLDs
Single line diagrams, panel schedules and cable lists parsed into tags with their drawing reference retained.
- 03
Attach vendor FAT to the tag
Factory test certificates filed under the equipment they qualify, as prerequisites rather than transmittals.
- 04
Run SAT and protection testing
Site acceptance, relay configuration and interlock proving signed against the bay in the field.
- 05
Gate back-energisation
The energisation certificate stays blocked until earthing, protection, interlocks and safety systems are proven.
- 06
Export for the transmission owner
Per-subsystem dossiers with certificates, records and punch status ready for OFTO or TSO transfer.
FAQ
Questions about Offshore substations scopes.
Keep reading
Offshore wind commissioning
The full sector view: fleet-wide record sets, offline execution at sea, energisation gates and takeover.
Read moreCertificates
Mechanical completion, energisation and takeover certificates issued from signed records, per asset.
Read morePunch lists
Defects raised at the asset with photos, categorised by whether they block energisation or takeover.
Read moreOther wind project types: Fixed-bottom wind farms, Floating offshore wind, Array and export cables, HVDC converter stations, Onshore substations and grid connection, Turbine installation and pre-assembly campaigns, Takeover, warranty and major component replacement, Onshore wind farms.
