http://www.sunnyday.it/ENG/(ENG)Chi_Siamo.htm
reliability
Installations of panels that have been exposed to all kinds of
weather for 15 years show that Sunnyday is practically indestructible.
This reliability is a feature of the particular polypropylene compound,
which is not damaged by ultraviolet radiations, maintains its elasticity
at �20�C, is insensible to mechanical shocks, hail, and shakes caused by
high winds. Moreover Sunnyday is insensible to saltiness and acids.
AND
http://www.quantumenergy.com.au/general/thinking.htm
As the Quantum Compact does not use any panels it cannot be
damaged by heavy hail, as the glass panels of a conventional Flat Plate
solar often can be. Solar Boosted models do not have any glass in their
panels to be damaged by hail. Although some denting of the panel may
occur, under normal circumstances the operation of the unit should not be
affected. Extreme hail conditions may damage the panel.
