what if solar string monitoring was an affordable, temporary solution?
TRANSCRIPT
What If String Monitoring Was An Affordable, Temporary Solution?
Historical Problem of String Monitoring• It’s too expensive• Day to day monitoring not
particularly valuable…but periodic checkups make sense
• The real cost are the underperforming strings you don’t know about…
To compensate for lack of detailed string monitoring, owners look to:
– Zone monitoring at inverter inputs
• Problem: Lacks detail– Commissioning reports
• Problem: Just 1 point in time
Temporary string monitoring analyzes site data a few times
a year, at a fraction of the cost.
The goal?
Find issues behind underperformance.
Common Output Issues Found by String Monitoring
• Loose/broken/melted MC4 connectors
• Soiling/dirt accumulation• Module shading• Blown fuses• Cracked cells• Terrain effects
Cost of ONE Problem Per String
• $330/month per MW• Over 20-year lifecycle:
$80,000/MW
HOW SOLAR STRING ANALYSIS WORKS
Engineers set up temporary hardware next to combiner box
(non contact).
Split core current transformers (CT) measure current of each string, and are
installed without taking the site
offline.
Data collected in five minute intervals for at least one
clear sky day.
CTs moved to collect data from each plant combiner
box.
Combiner box data inputs
normalized and analyzed to
calculate impact to energy.
Report provided to owner outlining
underperformance components with
likely causes.
GOALS OF SOLAR STRING ANALYSIS
Calculate deep dive analysis on energy lost from underperforming strings
Provide proof for warranty claims
– Module hardware– EPC labor and
service
Outline specific location data and likely causes
Analyze and provide recommendations on DC health
SOLAR STRING ANALYSISCASE STUDY
Affinity Energy’s Rooftop• 30kw• 3 inverters• 4 strings per inverter• Net-metering
building electrical usage
What String Analysis Told Us• 1 string not operational
– Found melted MC4 connector
– Cost us $60/mo for 18 months
• 3 inverters affected by shading
• Repairs helped increase energy yield by 8%
We want to help owners make critical decisions about maintenance to achieve optimal financial fitness and ensure long
term plant viability.
Ultimately…
