Solar String Analysis

Solar String Analysis

Are You on Track to Meet Pro Forma Energy?

Affinity Energy’s Solar String Analysis is a temporary solution of data collection, analysis, and reporting that provides the data to determine if a utility-scale solar site is underperforming. Ultimately, it improves PV system and O&M activities by enhancing the data needed by owners and operators to make critical decisions about maintenance.

Solar String Analysis

The Solar String Analysis system works on any age site or size, independent of typical solar SCADA or other solar monitoring solutions. It goes beyond typical site commissioning or zone monitoring to analyze combiner box data inputs to calculate the energy lost from underperforming strings. Because the data collection simply involves clamp-on CTs, re-termination or site shutdown isn’t necessary.

Affinity Energy engineers with 30+ years and 2,000 MW of utility-scale solar plant controls, instrumentation, and data acquisition expertise then analyze the data in an apples to apples comparison of string current to determine likely causes of underperformance.


Solar String Analysis pinpoints causes of underperformance such as:

  • Loose or broken MC4 connectors
  • Soiling/dirt accumulation
  • Module shading from various sources (trees, transmission lines, row to row, etc.)
  • Blown fuses
  • Cracked cells
  • Effects due to terrain


Solar String Analysis helps solar site owners and operators:

  1. Know where to direct O&M efforts
  2. Determine if the plant is on track to meet its pro forma energy and financial goals
  3. Identify energy loss and potential impacts to energy production
  4. Provide proof for service or hardware warranty claims
  5. Go beyond commissioning in a deep dive analysis of underperformance

According to data collected and analyzed in the Solar String Analysis process, the average site has about 1-2 problems per MW.


Affinity Energy’s Solar String Analysis has a 5-step process:

  1. Set up temporary hardware next to the combiner box (non-contact engineering).
  2. Collect data in five-minute intervals for at least one clear-sky day.
  3. Collect data from each combiner box.
  4. Normalize and analyze data to calculate the impact to energy.
  5. Provide a report outlining underperforming components with likely causes.

According to the PV Reliability Operations and Maintenance Database Initiative (2014), “assuring long-term plant reliability, through initial design and lifecycle O&M choices, is an increasingly important driver of…overarching financial fitness and future market development prospects.”

In a nutshell, Solar String Analysis better informs owners and operators on where to allocate O&M financial resources in order to help them achieve optimal financial fitness.

Ready to find out more?

Contact us today to discuss your project.