danger with disconnected solar panels?

[petersolar]

Hello,

When we purchased our home eight years ago, it had a 17 year old solar hot water system that included a 120 gallon tank and three solar panels. We've used it successfully in conjunction with an auxiliary gas powered water heater ever since. But now, the system is 25 years old, the tank is in bad shape, and the pump, expansion tank, sensors, valves, etc are rusty, crusty creatures. The cost of replacing everything is too high for us to justify with our current budget, so we have had the tank drained, the glycol drained, and the tank and associated equipment removed. Only the solar panels and insulated piping for the glycol remain on the roof.

Questions:

Is there any possibility that the solar panels will generate heat to the glycol piping (that has been drained) and insulation that would cause a dangerous situation, similar to a tea kettle without any water in it sitting on a heated stove burner? What would be the best way to avoid such a problem?

How could I determine what value if any the solar panels might have? They are vintage 1985 but still in good shape.

Thanks.

Peter

[Mike90250]

Really, you will save more, by replacing the "rusty crusty" gear, and allowing the sun to do most of your water heating. If you had a properly working system, and now you don't, you should see higher fuel bills. (increase of THERMS used, not just rates going up).

So, if you think the remaining gear on the roof is good, why not use it?

There is no way I can read an email, and give a guess as to $$ .

As to overheating, just slap a sheet of thin plywood over the collectors, and attach it in a non-damageing way. That will keep the terrible radiation from the remote fission reactor from overheating anything.

[ed2kayak]

I agree w/Mike have a local solar thermal person check it out. It may only need fresh glycol and a tuneup.

[peakbagger]

If the panels are good (not leaking) its worth bringing them back into operation as its hard to beat low cost hot water.

If its just not in the cards, the panels shouldnt be a safety issue up on the roof as long as the piping isnt sealed off. If they are down on the ground and are of proper construction and will hold pressure, the going rate for used panels seems to be around $300 each. In order for them to be worth anything, they should have all copper piping, glass glazing and aluminum frames and most importantly no leaks.

If they are up on the roof, if you are lucky, someone may take them down for free. I would be real careful with that option as the damage they can do taking them down and the potential liability is very high.

[Totti-Micoe solar heater]

May I know your location? If the sunshine is good in most of days, I suggest you to use some plastic cloth to cover the pannel to prevent it absorb heating for the sun.

You can check the panels, if they are still good, you could buy new tank and pump and other accessories to use them.