Friday, July 13, 2007

A really good exsample of why solar panels must be designed for servicing

These panels are of unknown make and are from 10-15 yrs old. It has heavily corroded copper surfaces and you can see the leaking hot water from the pipe in the 3rd photo, leaking several liters of hot water per hour (Bottom right of picture) and probably for more than a few years. You will also note the absence of any lagging on the pipes.

Points: - Fortunately, this is of a thick copper design. It can presumably be stripped, cleaned and restored to as good as new.
- Where different metals meet (Such as galvanised steel fittings on copper pipe), corrosion is inevitable.

- No air vents to allow moisture to escape, so this needs to be recitfied and the glazing seals replaced.

These panels show that it may be misleading to give the impression that any solar panels can be "set and forget" other than needing the occasional wash. Few structures can be expected to last 20 years exposed on a rooftop for 20 years without requiring a decent service now and then. Design should be such that panels can be conveniently dismantled and serviced as required.

What is also shown here is the corrosion that is likely to occur when different metals are in contact, setting up galvanic corrosion. This includes metal on metal contact with a metal roof as well as differing plumbing fittings. Once started, the only practical remedy is full replacement of the corroding parts.

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