By AGILE Consulting Engineers, Solar PV and Battery Energy Storage Systems (BESS) specialists.
Most solar and Battery Energy Storage System (BESS) projects that run into serious trouble were not undone by one dramatic failure. They were undone by a handful of ordinary, foreseeable risks that nobody was independently checking for until they had already compounded. An Owner’s Engineer (OE) does not eliminate project risk, no adviser can promise that, but a structured, independent review does materially improve the odds of catching these risks while they are still cheap to fix.
Table of Contents
- Design Risk
- Equipment Quality Risk
- Construction Quality Risk
- Schedule Risk
- Underperformance Risk
- Compliance and Connection Risk
- Why These Risks Compound
- What to Do Next
- FAQ
Design Risk
Design risk covers the possibility that the plant, as designed, does not actually suit the site or does not meet the owner’s technical or commercial objectives. This can be as fundamental as a geotechnical assumption that does not match actual ground conditions once piling begins, or as specific as an electrical protection scheme that has not been properly coordinated across the plant’s voltage levels. Design risk is highest early in a project and cheapest to correct early, which is exactly why independent design review typically front-loads an OE’s engagement rather than treating it as a late-stage check.
A related but distinct version of design risk is scope and interface risk, where individual design packages, for example civil, electrical and the grid connection asset, are each internally consistent but do not properly interface with each other. These gaps are notoriously hard for a single-discipline design team to catch in its own work, which is one of the more concrete reasons an independent, cross-disciplinary review adds value beyond what the EPC’s internal process already provides.
Equipment Quality Risk
Equipment quality risk relates to whether the modules, inverters or power conversion system (PCS), battery cells, transformers and balance-of-plant equipment specified for the project will perform reliably over the project’s intended life. This is not simply a matter of choosing a well-known brand, since even established manufacturers vary in quality across different product lines, factories and manufacturing batches, and since long-term reliability data for newer battery chemistries and inverter platforms is still relatively thin compared with equipment that has been in the field for a decade or more.
Independent equipment review typically involves checking manufacturer test certification, reviewing Factory Acceptance Testing (FAT) protocols and results, and assessing warranty terms for gaps that would leave the owner exposed if a particular failure mode is excluded. This kind of review is one of the areas where independence matters most, because an EPC with an existing supply relationship has less incentive to interrogate a preferred vendor’s claims as rigorously as an adviser with no stake in that relationship.
Construction Quality Risk
Construction quality risk is the gap between what was designed and what actually gets built on site. Torque specifications not met on tracker mounting, cable terminations completed without proper crimping procedure, or earthing and bonding work that does not match the approved design are all common examples that are individually minor but can, in aggregate or in the wrong location, create real safety and reliability exposure. Because a solar farm or BESS site can extend across large areas with many crews working in parallel, consistent quality across the whole build is genuinely difficult to achieve through the EPC’s own supervision alone.
Independent construction oversight generally relies on a sampling and audit approach rather than inspecting every connection point, focusing attention on higher-risk work such as high-voltage terminations, structural connections and battery enclosure installation, while tracking whether defect rates found in sampled work suggest a broader systemic issue that warrants wider investigation.
Schedule Risk
Schedule risk in solar and BESS projects tends to concentrate around equipment lead times, grid connection approval timeframes, and the sequencing dependencies between civil, electrical and commissioning works. A schedule that looks achievable in a Gantt chart can hide unrealistic assumptions about how quickly commissioning issues will be resolved or how long connection compliance testing will actually take once problems are found. Independent schedule review does not try to replace the EPC’s own project controls function, but it does provide the owner with a second opinion on whether milestone dates are realistic, which matters directly for financing covenants and any revenue assumptions tied to a commercial operation date.
Underperformance Risk
Underperformance risk is the possibility that a completed, commissioned plant does not deliver the energy yield or capacity that its financial model assumed. This risk traces back to several of the categories above, since it can stem from an overly optimistic yield assessment at the design stage, equipment that underperforms its nameplate specification, or construction defects that reduce output without necessarily causing an outright fault. Because underperformance is often invisible until enough operating data has accumulated, catching the contributing assumptions and defects earlier, during design review, FAT and commissioning testing, is considerably more effective than trying to diagnose the cause after a year or two of disappointing generation data.
Compliance and Connection Risk
Compliance and connection risk covers the possibility that a project does not meet the Generator Performance Standards (GPS) agreed with the network service provider and AEMO (Australian Energy Market Operator), or does not satisfy other regulatory obligations tied to registration in the National Electricity Market (NEM). This risk is particularly costly when discovered late, since a plant that cannot demonstrate compliance during commissioning testing may need equipment changes, control system reparameterisation or protracted retesting before it can commence commercial operation. AEMO’s own reporting has shown grid connection application volumes rising sharply, with average processing time still measured in months rather than weeks, which puts a premium on getting the technical studies and performance standard negotiations right the first time rather than relying on rework cycles with AEMO or the network service provider to catch errors.
Why These Risks Compound
These six risk categories rarely stay isolated. A design risk that goes uncaught can flow into equipment selection, which can flow into construction quality issues, which then surfaces as underperformance or compliance failure well after the point where it would have been cheap to fix. The value of an OE is less about spotting any single risk in isolation and more about maintaining a consistent, independent line of sight across the whole chain, from design assumption through to as-built performance, so that a problem introduced early does not silently propagate through to commissioning.
What to Do Next
Most of the risks outlined here are not unusual or exotic, they are the ordinary failure modes documented across the solar and BESS industry, and most are genuinely easier to manage with an independent set of eyes involved from early in the project. This is the point where an independent technical review early in a project can save months of rework later. We’ve helped project teams work through exactly this before committing to contracts.
FAQ
Which of these project risks is the most common in practice?
Underperformance risk tends to get the most attention because it directly affects revenue, but it is usually a downstream symptom of design, equipment or construction quality risk rather than a standalone category, which is why addressing the earlier risks tends to be the more effective intervention.
Can an Owner’s Engineer guarantee a project will avoid these risks entirely?
No responsible adviser can offer that guarantee, and any claim to the contrary should be treated with scepticism. Independent review reduces the probability and cost of these risks materialising; it does not eliminate risk from a construction project.
At what point does construction quality risk become hardest to fix?
Once civil and electrical works are covered over, buried or enclosed, for example cabling covered by trenching backfill, verifying quality retroactively becomes far more disruptive and costly, which is why independent construction oversight is generally scheduled to inspect at key stages before that work is closed in.
How does compliance and connection risk differ from other risk categories?
Compliance and connection risk is unique in that it involves an external regulatory party, AEMO and the network service provider, whose approval is required before the plant can operate commercially, meaning it carries a hard go or no-go consequence that some of the other risk categories do not.
Does schedule risk matter as much for equity-funded projects as for debt-financed ones?
It matters for both, though debt-financed projects usually have contractual milestones and covenants tied directly to schedule, which raises the financial consequence of delay, while equity-funded projects still face commercial and opportunity cost from schedule slippage even without formal covenants.
What is the earliest point an Owner’s Engineer can start reducing these risks?
Ideally during feasibility and design development, before an EPC contract is signed, since design risk and equipment selection decisions made at that stage set the ceiling for how much later risk can realistically be avoided.
