Every solar system in operation has an expected production value that is calculated based on system size, equipment type, and location. The best way to make sure your system is performing at peak capacity is by monitoring it through a DAS (Data Acquisition System). Making sure your DAS monitoring is operating, accurate, and functional is essential to hitting production values. Furthermore, the number one way to avoid underproduction is to make sure someone is monitoring the DAS on a regular (daily)basis and being proactive in responding to alarms and alerts and underproduction trends.
A key indicator that there is a production issue is to monitor the irradiance graph, weighted against the production values. As irradiance increases (longer/sunny days), you should normally see production increase. If that is not the case, there is most likely an issue with soiled panels, or another issue that needs to be addressed in the field.
Attention to detail is important, along with a willingness and the resources to respond to any issues that may arise. Having a team that can address underperformance issues in the field efficiently and timely, is essential to the success of a PV system.
If the DAS system has alerted of a performance issue, a technician will need to do a site visit to perform an assessment and remediate the problems. The most common culprits of underperformance are:
Module Soiling
Dirty Panels cannot perform at peak efficiency. If you are not in a climate that rains often, make sure module cleaning is part of your maintenance routine. A contractor that performs module cleaning, should also make sure to clean the irradiance (pyranometer) sensors so that the DAS is accurate and not providing false date because of soiling.
Shading, including seasonal shading.
If the array is being shaded by vegetation, buildings, equipment, etc. production will be affected. Keep in mind that the angle of the sun may cause shading on the array in certain seasons, but not others.
Defective or underperforming solar panels.
If a panel is broken or damaged performance will obviously be affected. Find a contractor that can detect and replace defective modules when this issue arises.
Weather
It’s no secret that solar relies on the power of the sun, but the weather and climate of a region may affect production more than you realize. Season, hours of sunlight, angle of the sun, and temperature will all affect production numbers. For example, temperature and heat can negatively affect production, as solar panels perform best in weather that is sunny, but not extremely hot. Hot climates take a toll on equipment, so a region that is ALWAYS hot and sunny may not perform as well as expected. It’s important to look at irradiance trends for a specific location to determine if production values are normal. Weather can be monitored but it cannot always be predicted, but it is important to ask, “Is this weather pattern normal and expected?”
Lack of Maintenance
Preventative and corrective maintenance is key to hitting production numbers year after year. A site that is monitored effectively, has a preventative maintenance plan in place, and receives timely and effective corrective maintenance can often perform well past many other solar assets that do not receive the same care and attention to detail.
Every owner must ask themselves two questions if they hope to have their systems performing at peak capacity year after year:
1. What monitoring is in place to ensure underperformance is not overlooked?
2. How do I maintain the expected production through an effective maintenance plan?
If both are addressed, systems can perform at expected production values and targets are achived.
If you are looking for a trusted contractor to perform PV maintenance and repairs on your solar system, contact Day Electric today.
About Day Electric
Day Electric is a full-service solar O&M service provider with complete project design, procurement, commissioning, repowering, and construction management capabilities. The company also provides professional operations and maintenance services for solar power plants as well as small businesses and residences. With completed projects spanning government, education, commercial, and municipal customers. The Day Electric portfolio of projects makes the company one of the top solar PV service firms. For more information about professional O&M services for your PV system, contact Day Electric by phone at (434) 333-0355 or online at www.dayelectricusa.com