Inverter failures are one of the most frequent types of failures on a solar PV farm, accounting for 17% of total incidents in our dataset. It can also lead to significant associated costs. Physical damage from inverter incidents costs an average of $42,483.
Understanding where the risks are coming from and how to properly mitigate them is critical to decreasing the associated risks and costs.
What causes inverter failures?
Inverter electrical failures are the most common component failure at a PV farm. Although the majority of inverter’s electrical faults are not catastrophic due to the presence of an adequate protection design, these failures can lead to significant business interruption risk and property damage. This can lead to high associated costs from lost revenue on the farm.
The most common causes of failures are design and manufacturing defects, installation errors, overheating. Design failures are related to the premature aging of critical electronic components. Since components are designed for certain conditions, anything outside of those conditions can put inverters at risk for failure. Installation errors are also common with inverters and it’s extremely important to test at handover and commissioning.
Where a solar farm is located can influence inverter failures, as well. Hot and wet environments—categorized as environments with a mean temperature above 14°C and 55% humidity—provide the worst conditions, as it leads to overheating, moisture ingress and condensation within the inverter, easily resulting in electrical failures. Cold, dry weather—under 14°C and 55% humidity—provides the ideal environment for inverters with the probability of failures low.
Catastrophic inverter failures are mainly due to two reasons:
- Insulation breakdown as a result of a short circuit between various parts of the circuit board.
- The malfunction of any of the internal components, such as insulated-gate bipolar transistors (IGBTs), communication board or capacitors.
Costs associated with inverter failures
Inverters represent the some of the highest costs related to failures. This is due to the high costs related to business interruption and downtime, as well as the high costs related to the components. According to Clir’s database, critical or major inverter claims have an average downtime duration of 80 days. This is likely due to repair complexity and the availability of spare parts. Business interruption can cost upwards of $49,392 due to lengthy repair times.
Inverters can involved more intricate repairs due to the technical nature of the components. This also depends on the complexity of the damages related to inverter failures. Inverter components also have long lead times for replacement. Most manufacturers don’t have a contractual obligations with the inverters, which means that the O&M team typically has to source repair parts, resulting in long delay times.
Mitigating inverter risks
Since many PV modules are connected to the inverter, failures can result in large portions of the farm being offline. Mitigating or minimizing the risks is critical for minimizing losses.
Since inverter downtime is a key contributor for revenue and production losses, mitigation strategies typically involve sourcing and storing spare parts. This can reduce wait times related to sourcing parts, although clients will still experience delays due to repairs.
Many risks — and the related necessary mitigations — are dependant on site conditions, such as the region and remoteness of the PV farm. Clir’s operational and claims data provides insight into how the industry is managing risks, which client’s can leverage to develop site-specific mitigation plans. This can reduce losses, increase revenue and help communicate risks for insurers.
