The economics of solar farm cleaning has very little transparency. Many question if it makes economic sense to clean solar installations. PVworx recently cleaned a 53 MW installation in Florida and the general economics of the project are available in this article to help bring clarity on the subject. The value of solar maintenance can be measured and in this example, the net profit from investing in solar farm cleaning was estimated to be $46,751 + Asset Life.
The Value of Solar Panel Cleaning
According to a solar farm cleaning course offered by the North American Board of Certified Energy Practitioners® (NABCEP®) and Soilar Technologies a leading PV soiling engineering firm, solar farm cleaning increases performance, energy reliability, asset life, and warranty compliance.
4 Main Drivers for Solar Panel Cleaning
Measurable Value of Solar Panel Cleaning
Performance is the leading indicator of solar panel cleaning value and this can be measured in multiple ways including inverter data and PV soiling data. In this project, 3.99% of annual revenue was lost due to PV soiling if no action was taken. Solar panel cleaning or better yet “PV soiling mitigation” will not reduce soiling levels to cero permanently hence our preference for using the term “PV soiling mitigation”. The reduction of PV soiling levels will improve performance and hence revenue. In this project, the net gain is $46,751 dollars + Asset life with one cleaning.
High soiling levels will compromise the energy quantity agreed to in a PPA agreement (Power purchase agreement). As the world transitions to solar energy as a main energy source, creating reliable power will be part of many PPA agreements.
The warranty guidelines across PV module manufacturers are contradictory and are being updated constantly as the science of PV soiling mitigation evolves. First Solar offers these guidelines for cleaning solar panels. As you can see below, the guidelines are vague and inadequate for solar farms and more applicable to residential solar panel cleaning. The mention of ARC (Antireflective coatings) is a valid statement if the brush is highly abrasive and has not been tested. PVworx uses the tractor brush system by Sunbrush which has had its bristles tested by laboratories in Europe for abrasion levels and has past the test.
Asset Life Extension
PV soiling is the leading cause of Hotspots
Asset life prolongation due to regular maintenance has not been measured to date but the effects of not cleaning have been measured. According to NREL, the 3 main drivers for solar panel hotspot development include.
- PV Soiling / Shading
- Mechanical Damage
- Internal Module Failures
Hot spots cause the heating of adjacent cells and cause a significant decrease in output power.
Solar panels are sold with an expected lifespan of 25 years if they are maintained regularly. If they are not cleaned, and soiling is constant then hotspots will be constant and they will not make it to 25 years. Hotspots will ruin a solar panel and cleaning helps to avoid the development of hotspots.
Solar Farm Specifications
212900 250w First Solar Thin Modules
Estimated Site Revenue at full production = $ 6,383,850.00
15-20% production increase when checking several areas of the farm