Hidden Failure Detection Prevents 197 MWh of Energy Loss in PV Inverter

In many solar PV plants, SCADA alarms only react to communication errors or critical trips, so hidden performance losses can run for months without any alert. This “invisible” SCADA failure is an electrical or operational issue that reduces production but does not trigger traditional alarm thresholds.

Delfos solves this industry problem by continuously comparing the specific production (kWh/kWp) of each inverter and string against similar assets. In this case, the platform highlighted one inverter with much lower specific production than inverters of the same nominal power, flagging a hidden failure that SCADA alone could not see.

The plant was unknowingly losing energy because one inverter was operating with significantly reduced specific production over several months. Without advanced analytics, this kind of loss is typically only discovered after a physical inspection or a revenue gap.

Delfos used its predictive analytics platform to detect the anomaly early and quantify the lost energy. By pinpointing the faulty inverter and the affected strings, the O&M team corrected the issue and avoided an estimated 197.42 MWh of additional lost production over a six-month period, directly protecting revenue.

Traditional SCADA systems are not designed to capture every type of performance degradation. In this case, the CC2 breaker was disconnected and had a communication failure, so the associated strings were not producing energy but no SCADA alarm was generated. From a control-room perspective, everything appeared normal.

Delfos bridges this monitoring blind spot by using performance-based alerts instead of relying only on SCADA tags. The platform detected that the inverter’s specific production had dropped by more than 40% (from about 22 kWh/kWp to ~12.9 kWh/kWp) and highlighted the issue to the O&M team, even though SCADA reported zero alarms.

In large PV plants, O&M teams struggle to see which strings are driving losses across thousands of data points. Manually checking each string in SCADA is time-consuming and often reactive.

Delfos solved this by combining two key tools in its platform:

1. Lost Energy Ranking

This feature ranked the non-generated energy by string, showing exactly where the largest losses were concentrated inside the inverter.

2. Deviation Analysis

The deviation tool compared the normalized DC power of each string against expected behavior, clearly exposing eight inoperative strings. Together, these analyses led the Engineering team directly to the disconnected CC2 breaker as the root cause.

When hidden failures persist, solar plants suffer from lower yield, underestimated performance risk, and unnecessary site inspections. Fixing problems late often means permanent revenue loss.

After Delfos reported the anomaly in the regular Engineering & Performance meeting, the O&M team acted quickly and corrected the breaker and string issue. The inverter returned to the expected specific production pattern, again aligned with equivalent inverters. As a result:

• An estimated 197.42 MWh of future energy losses were avoided over six months.
• Eight disconnected strings were restored to normal operation.
• No preliminary field inspection was needed before taking the corrective action.

O&M teams often lack a clear, data-driven view of where to act first, especially when SCADA dashboards show “no alarm” but production is underperforming. This leads to low-priority tickets, reactive work, and missed revenue.

Delfos turns plant data into actionable insights by ranking lost energy by asset, comparing inverter and string behavior, and highlighting deviations that matter for revenue. In this case, Delfos translated abstract SCADA and field data into a concrete, high-impact maintenance action, enabling precise and fast intervention instead of broad, exploratory inspections.

Many plants track only basic KPIs, which can mask serious underlying issues. Without deeper analytics, metrics like “availability” and “alarms count” are often misleading for revenue protection.

Delfos focused on KPIs directly linked to value in this case:

• Energy recovered: 197.42 MWh of energy losses avoided (six-month estimate).
• Root cause: eight disconnected strings due to the CC2 breaker issue and communication failure.
• SCADA behavior: 0 alarms registered during the entire failure period.
• Performance deviation: more than 40% drop in specific production, from ~22 kWh/kWp to ~12.9 kWh/kWp.

By tracking these KPIs, Delfos directly links technical anomalies to financial impact, helping asset owners and O&M teams prioritize what truly moves the P&L.

Relying only on SCADA for fault detection exposes solar portfolios to invisible losses and delayed interventions. SCADA is essential for control and safety, but it is not designed to quantify lost energy or benchmark asset performance.

Delfos complements SCADA with AI-driven performance analytics and clear lost-energy insights, as highlighted below:

Solar operators often notice underperformance late, either in monthly reports or when contractual KPIs are already at risk. Waiting for manual analysis or generic reports to reveal issues can lock in permanent revenue loss.

Delfos is most valuable when you want continuous, proactive surveillance of inverter and string behavior. The platform automatically monitors specific production, lost energy, and deviations across the fleet, and then surfaces anomalies in regular Engineering & Performance reviews. This gives O&M teams the time and clarity they need to correct failures before they escalate into major financial losses.

AI and analytics only create value when they change operational decisions and protect cash flow. Many tools stop at dashboards, leaving O&M teams unsure how to act on the information.

Delfos connects predictive insights with concrete O&M actions. In this case, the platform not only detected the anomaly but also indicated the affected inverter, strings, and likely electrical cause. This enabled a precise, low-cost corrective action that avoided 197.42 MWh of future energy losses, increased operational reliability, and generated direct financial returns for the asset owner.