How does hail affect solar panels?
Modern Tier one quality solar panels that are correctly installed and tilted are built to withstand hailstones of a certain size and velocity. Manufacturers test their panels for durability and impact resistance, and they usually provide information about the specific hail rating for their products. This rating indicates the size and speed of hailstones that the panels can withstand without significant damage.
If the glass cover over the panel's cracks, the underlying soil could be contaminated with lead (however, lead-free panels are now available but may not be economically viable yet). These small amounts of contaminants tend not to leach. Instead, they bind to soil and runoff when sediment is eroded. However, there is a moderately low risk of sediment loss to waterways if the solar farm is managed well. As the solar panels are wired in series of up to XX panels, a broken panel would cause the whole XX panels to stop production and trigger an alarm.
In addition to the above, any cracked solar panels are quickly rectified as most Solar farms have stringent Operations and Maintenance contracts, including onsite and remote monitoring (part of the lending requirements to fund solar farm construction). In addition, spare panels are kept on site for such events and will be swapped out within a few days of breakage. Also, when a panel breaks, the glass sits on the vinyl back sheet of the panel, and very little falls onto the ground. Therefore, the risk of glass or panel components being washed away with stormwater and into drains is highly unlikely.
For additional information:
A comprehensive set of guidelines available from an independent organization has been put together by the International Energy Agency:https://iea-pvps.org/publications
The “Human health risk assessment methods for PV Part 2: Breakage Risks”
Hail Resistance
Solar farms built in hail-prone areas should be procuring PV solar panels that are designed and tested in accordance with the IEC performance standards. These go above and beyond the requirements covered by AS/NZS standards:
- IEC 61730-1: Photovoltaic (PV) module safety qualification - Part 1: Requirements for construction https://webstore.iec.ch/publication/25674
- IEC 61215-1: Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 1: Test requirements https://webstore.iec.ch/publication/61345
More useful links related to extreme weather management for solar panel installations:
https://eif-wiki.feit.uts.edu.au/_media/solar_panel_iec_standards_testing.pdf
https://www.nrel.gov/docs/fy22osti/81968.pdf
