The PV Health Scan



A diagnostic health and performance check of PV plant operation

The PV Health Scan is a software-driven service for PV plant owners, operators and asset managers. It ensures the early detection of faults and performance degradation and gives you actionable recommendations on the root causes. This allows you to improve your performance return by more than 10%. We are able to do this by mining your PV monitoring data on our SynaptiQ platform.

Professionally designed and maintained PV plants often perform well above business plan. At the same time, the spread in performance ratio (PR) is still very high, often even within a portfolio of plants. A review of monitoring data from 197 plants monitored by SynaptiQ from summer 2015 (Figure 1) shows that:

  • The best 25% of plants perform more than 3% above expectations
  • The worst 25% perform more than 8% below expectations

Figure 1: Performance ratio (PR) from monitoring versus expected PR based on plant specification and real weather data for 197 PV plants in Europe; the dot size represents the size of the PV plant

The big causes of unavailability like inverter failures and plant outages are usually identified and repaired easily. However, many of these plants are affected by smaller, hidden faults, like bypass diode failures, disconnected sub-arrays, and creeping degradation, e.g., due to optical or potential induced degradation (PID). The root causes for these faults can mostly not easily be inferred from a quick review of the high-level monitoring data. If not followed up, these effects tend to add up and worsen over time.

For plants monitored by SynaptiQ, 3E is now offering a PV Health Scan. We mine the monitoring data and identify the root causes of bad plant performance. Clients can opt for a one-time diagnostic check of the past operation, e.g., when a plant is to be retrofit or sold. And they can receive monthly or quarterly updates to support the work of their asset managers.

Figure 2 shows the different loss types on string level for a plant with 600 strings and four inverters. The worst performing strings are sorted to the left hand side and will be listed for a detailed check.

Figure 2: Performance losses on string level over one month; split per loss type and sorted in descending order; for a plant with 600 strings distributed over four central inverters

The PV Health Scan covers:

  • a performance breakdown over the energy conversion chain
  • a performance breakdown for the different components (inverter, array, string);
  • An identification of underperforming PV inverters, arrays, strings over time;
  • The rate of annual degradation per PV array.

It includes conclusions on the most probable root causes and recommendations on how to solve them.