Commissioning

This page answers one question: who is permitted to commission your system without affecting your warranty?

Note the word. Not capable — permitted. A competent high-voltage team can commission a battery system from the manuals. Whether they are contractually allowed to is a different question, decided by documents most owners do not read until something has already gone wrong. Only the second question costs money.

1. This is a warranty question, not a service preference

Two independent public sources make the position plain.

Manufacturer warranty terms. Sungrow’s manufacturer warranty provides that installation, commissioning and removal shall only be carried out by certified personnel authorised by Sungrow or its approved service partners. Independent guidance on the same terms records that unauthorised repair, adjustment or modification voids cover.

Independent industry guidance. Published guidance on battery storage warranties notes that manufacturer cover may be conditional on signing a long-term service agreement, on a remote monitoring plan, or on the use of an approved O&M provider — and that failing those conditions can invalidate the warranty.

Read together, the position is this: on much Chinese-manufactured equipment, the identity and authorisation status of whoever touches the system is a term of the warranty, not a matter of preference.

Two consequences follow, and they are asymmetric:

• If your commissioning party is authorised, nothing happens. This is the invisible good outcome.
• If they are not, you may have a system that works perfectly and a warranty that does not — and you will discover it at the first significant failure, years later, when the evidence is cold.

Because the asset sits on your balance sheet, the exposure is yours, not the contractor’s. A contractor who commissions your system without authorisation has not breached anything; you have.

What to check, and where

If you take one thing from this page: check those three documents before the O&M scope is fixed, not after.

2. What site acceptance catches that factory acceptance misses

Factory acceptance testing is not optional theatre. Published findings from FAT programmes on utility-scale battery systems record the defect rate at the point of shipment:

• 28% of systems showed fire detection or suppression issues
• 19% had auxiliary board faults
• 15% had thermal management defects
• 6% failed capacity testing outright

Roughly one system in four leaves the factory with a fire-related defect.

But FAT tests a system in a factory, not a system in a field. Site acceptance testing exists because a container that passed in Suzhou has since been lifted, shipped, stored, craned into position, and connected to a grid it has never seen. The categories SAT covers that FAT structurally cannot:

• Transport and handling damage — connections loosened, enclosures deformed, cables chafed
• Interconnection — everything between the container and the point of connection, which did not exist in the factory
• Grid interaction — protection settings, ride-through behaviour, response to the actual network impedance at this specific point
• Site conditions — ambient temperature range, ventilation as installed, fire suppression as installed and commissioned
• System-level integration — PCS, DC block and EMS from three vendors behaving as one system, often for the first time

There is a further point, less often stated. The feedback loop from field to factory is largely broken. Once a system is installed and running, the parties who tested it in the factory rarely learn what happened to it afterwards. Problems that emerge in month three, month twelve or year three do not reach them. A commissioning record that is properly documented and retained is one of the few mechanisms that closes that loop — and it is worth doing for that reason alone.

3. Grid compliance, and the certification trap

Grid connection of a storage system in Europe runs through the EN 50549 series — EN 50549-1 for low voltage, EN 50549-2 for medium voltage, and EN 50549-10 covering the test procedures — sitting under the European Network Code on Requirements for Generators, which each member state implements through national grid codes.

The trap is this. A certificate under EN 50549-2 is issued against a specific equipment model, a specific firmware version, and a specific grid configuration. It is not a general statement about a product family.

Which means a supplier statement of the form “compliant with EN 50549” is not evidence of anything actionable. The questions that matter are:

1. Which model number is the certificate issued against, and does it match what is on site?
2. Which firmware version was certified, and does it match what is installed?
3. Which grid configuration was tested, and does it match this point of connection?
4. Who issued it, and is that body accepted by your network operator?

A firmware update after certification can, depending on scope, put the installed configuration outside the certificate. That is a real risk on equipment that receives regular updates, and it is worth establishing a version-control discipline at commissioning rather than discovering the gap during a compliance review.

4. Punch-list closure and handover training

Two deliverables that are routinely treated as administrative and are not.

Punch-list closure. Every open item recorded at commissioning is either closed with evidence, formally accepted as a deviation, or carried into the O&M scope as a known condition. An item that is none of those three is a dispute waiting for a trigger. The list should be signed off by name, with dates.

Handover training. Whoever operates the site afterwards needs the alarm taxonomy, the escalation path, the isolation procedure, the fire and emergency response arrangements, and the location of the documentation. Where the manufacturer’s own engineers are on site for commissioning, that period is the single best opportunity to obtain that training — the people who built the equipment are physically present, and they will not be again.

Illustrative scenario

A Flemish owner takes delivery of two 25 MWh sites with a Chinese PCS and DC blocks from a second Chinese manufacturer, integrated with a European EMS. The manufacturers send their own engineers for a one-week commissioning window.

Before the window, the owner’s team reads the two supply contracts against three questions: who may commission, who may maintain, and what conditions attach to warranty cover. One of the two contracts contains an authorised-partner requirement extending to maintenance. That single finding changes the O&M tender, because it narrows the field to parties who can hold that authorisation.

During the window, the owner arranges for their future O&M provider to attend for training alongside the manufacturers’ engineers. It costs the commissioning schedule nothing. It means the people who will operate the site for the next ten years were trained on these specific containers by the people who built them.

Illustrative scenario based on typical Benelux configurations — not a client reference.

How we work

We hold manufacturer service partner status where it is available, and we tell you plainly where it is not. We read your supply contracts and warranty terms before quoting an O&M scope, because quoting a scope that voids your warranty is not a service. Field work is performed by certified contractors under contract to BessRe; we hold the client relationship, the manufacturer authorisations and the commercial interface.

Response: 4/8-hour on-site response target across the Benelux, northern France, western Germany, London and Zurich; next-day on-site response across main European markets. Per contracted SLA.

Frequently asked questions

Can a competent electrical contractor commission our system? Technically, in most cases yes. Contractually, it depends on your supply contract and warranty terms, and on much Chinese equipment the answer is no without manufacturer authorisation. Those are two different questions and only the second one costs you money.

What should I look for in a grid compliance certificate? The model number, the firmware version, the grid configuration tested, and the issuing body. A general statement of conformity to EN 50549 without those four is not evidence.

We already had factory acceptance testing. Do we need site acceptance too? FAT verifies a system in a factory. SAT verifies the system you actually received, after transport, installation and connection to your specific grid point. Published FAT findings show roughly one system in four ships with a fire-related defect — which is an argument for doing both, not for skipping either.

Who should hold the commissioning documentation? You should. It is the evidence base for every warranty claim over the asset’s life, and it is the only record that survives a change of service provider.

What if we have already commissioned without checking authorisation? Then the position is worth establishing now rather than at the first failure. In some cases the manufacturer will accept retrospective regularisation. That conversation is considerably easier before a claim than during one.

Talk to our team before your commissioning scope is fixed — info@bess.re.

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