Solar Generation: Axis Tracking/Soiling Loss Calculation
Challenge
In solar energy generation, it is known that the soiling of panels and axis tracking faults (for panels with axis tracking capability) will reduce the total output of a solar plant. Generally, some flat number based on weather and assumptions, as well as total net output, is applied to determine when it becomes worthwhile to clean solar panels or fix/tune axis tracking controllers to maximize output. Developing models of the plant to account for these kinds of power losses is difficult or requires expensive and specific software that does not allow for much tuning or any ad hoc analysis of plant performance.
Solution
In Seeq, periods that exemplify optimal performance can be identified: The panels are clean and there are minimal tracking deviations from setpoint. These periods can be combined to create a training window. A model of plant performance based on the identified training window and plant meteorology instruments can then be developed to monitor the impact of axis tracking faults and soiling losses.
Results
The developed plant model allows for continuous monitoring of soiling and axis tracking losses, while also enabling a dollar quantification report to determine when the monetary cost of maintenance is justified by the losses associated with that maintenance.
Data Sources
- Wonderware
Data Cleansing
Capsules were developed to identify when each tracker string in a block was deviating by more than a given threshold from its setpoint. Formula was then used to combine all of these capsules and remove them from periods when the sun was shining.
Calculations and Conditions
- Value search, formula, composite condition, prediction, scorecard metric
Reporting and Collaboration
Results were documented in a set of scorecard metrics within a larger monitoring dashboard worksheet that was used by plant engineers to make data-based decisions and account for inefficiencies in the generating system.