A commercial solar system does not have to stop working completely to be under-performing.

At Candelori’s, a restaurant in Western Sydney, approximately 90 solar panels had been generating electricity for more than a decade. The approximately 29 kW system had reportedly paid for itself in just four and a half years, demonstrating the value the original solar investment had already delivered.

However, the business was now facing monthly electricity costs of approximately $8,000 to $10,000, and the owner was unsure whether the existing solar system was still performing as expected.

An inspection by Solar Service Guys, an Omnidian company, revealed why ongoing solar asset management matters.

The challenge: a system can be operating and under-performing at the same time

One of the difficulties with commercial solar is that performance problems are not always obvious.

A complete system failure is relatively easy to identify. Partial underperformance can be considerably harder to detect because other parts of the system may continue generating electricity.

That was the situation at Candelori’s.

The original system incorporated 290-watt LG solar panels and SMA inverters and had been operating for more than a decade. Much of the installation remained in very good condition, but the system had not been comprehensively inspected on the roof for approximately ten years.

Over that period, both the solar equipment and the building around it had changed.

The approach: monitor, maintain and manage

Commercial solar should be treated as a long-term energy asset whose performance is monitored, maintained and managed throughout its operating life.

Monitoring provides visibility into whether an asset is generating as expected. Maintenance and inspection help identify physical or electrical issues that may not be apparent from performance data alone. Active management allows businesses to determine when an issue should be repaired and when changing technology, energy consumption or site conditions justify a larger investment.

The Candelori’s inspection demonstrates why all three elements matter.

The physical inspection identified backsheet deterioration, lichen growth and cabling that had become unsecured after plastic cable ties deteriorated through UV exposure.

One panel had suffered a suspected hot spot severe enough to shatter the panel glass and leave visible evidence of burning.

The site itself had also changed. Air-conditioning equipment installed after the original solar system was creating shading across several panels, demonstrating how modifications to a commercial building can alter solar performance years after installation.

The proof: two strings were not operating as expected

Electrical testing provided clearer evidence of the performance problem.

One affected string was producing approximately four volts DC, compared with around 610 volts from a correctly operating string. A second string was also producing very low voltage.

Further testing identified two blown fuses associated with the two strings that were not working. Loose electrical connections were also identified at an inverter, which ultimately needed to be isolated.

At the time of the inspection, the restaurant was effectively losing the benefit of approximately 15 kW of its installed solar capacity.

Importantly, this was happening while other parts of the system continued to generate electricity.

For a commercial asset owner, that distinction matters. Simply knowing that a solar system is generating does not necessarily tell you whether the entire asset is performing as expected.

Why this matters beyond one restaurant

The issues identified at Candelori’s are specific to that site, but the underlying asset-management challenge applies much more broadly.

Commercial buildings evolve over time. HVAC equipment is replaced, roof infrastructure changes, businesses expand and electricity consumption patterns shift. Organisations may introduce EV charging, batteries, additional refrigeration or new machinery long after the original solar system was designed.

Solar technology is also evolving.

The Candelori’s system uses approximately 290-watt panels, while modern commercial modules can exceed 500 watts. For this site, the proposed next stage could increase solar capacity from approximately 29 kW to around 50 kW within the available roof area, together with battery storage to support significant evening electricity consumption.

However, newer technology does not mean every older solar system should automatically be replaced. The appropriate decision depends on the condition, performance and economics of the existing asset.

That requires evidence.

What should commercial solar owners do differently?

Businesses should move away from treating solar as an infrastructure project that ends at installation and instead manage it as an operating asset.

For a single commercial site, that means maintaining visibility over generation, investigating unexpected changes in performance and periodically assessing the physical and electrical condition of the system.

For organisations operating solar across multiple sites, the same principle becomes a portfolio-management challenge. Businesses need to understand which assets are performing as expected, which require attention and where maintenance, repair or capital investment should be prioritised.

A practical approach is to monitor performance, maintain the asset and manage its lifecycle.

That provides a stronger basis for deciding whether an ageing system should continue operating, be repaired, repowered, expanded or eventually replaced.

From solar ownership to solar performance

The Candelori’s system demonstrates that commercial solar can deliver value for many years. It also demonstrates why past performance cannot simply be assumed to continue indefinitely.

More than a decade after installation, the system was still generating electricity, but testing found two failed strings, two blown fuses, a damaged panel, inverter issues and approximately 15 kW of solar capacity that was not delivering its expected benefit.

For commercial solar owners, the question therefore should not simply be whether the organisation has solar installed.

The more useful question is whether you know how well those assets are performing today.

Omnidian helps businesses monitor, maintain and manage commercial solar assets throughout their operating life, providing greater visibility into performance and helping organisations identify issues that require attention.

Talk to Omnidian about the performance of your commercial solar assets.

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