Fred do you remember the last time this question was asked on here or was it Portugal someone had done just this.

The solar voltaic panel was just enough to run the pump and was linked through a control panel to an alternative mains supply. The idea was that the pool pump was run for a period at night on low tariff mains supply and again during the day from the solar panel. This struck me as very sensible (no expensive batteries for storage) for dull days.

However the cost if my memory is correct was of the order of €3000 and that made the payback almost indefinite. Of course cost in real terms will have fallen since then but with inflation I would guess about the same.

Its what is known in sophisticated language as a Ground Source Heat Pump (google is our friend) but you are spot on chlorinated warm water would eat through the panel in quick sticks.

I have a little experience, I was a plumber/heating engineer for about 45 years.

It was rhetorical question you already knew.

You might be interested in our experience.

We got a solar panel put on the roof 6 years ago, with a 50% grant, and this has provided all our hot water needs except for 2-3 months in the winter.

We wondered why these are not seen commonly all over Andalucia (as they are, for example, in the Greece). Why does everybody pay for hot water?

Perhaps now we know the answer. The high mineral content of the water has taken its toll on the system, and some of the connections have now failed at the supply tank. We're told that we need to replace the tank - and the cost of so doing is the same as the original installation.

There are many stories like this at the moment, people saying that it's just not cost effective. Surely a small panel just to power the pool pump would be though?????

It will take more than a small panel to power a pool pump which may well use 1.5kw depending on the size of the pool.

If you want to save money just cut down on the time it runs - ours is never run for more than 2 hours even in the height of summer. Most of the time it is only on for 90 minutes and it's off most of the winter.

Running it for 8 or more hours a day only applies to a heavily used pool.

hi, been offline. just spotted this. will see if he can help on my water deposito thermal store. just cemented the roof bit so nearly ready for tubes. thanks

sorry but obvious to me that having already discovered the hard water, that a] solar panel systems use treated water b] that fernox is used is its a closed system. do not the installers suggest/advise this?
we planned while ago to have softner system because told of the iffy water.
can i ask size of your panel astrying to work out sizing for my thermal store (for the winter heating)

I don't have a panel I'm just considering it at the moment

Perhaps our problem was that the system wasn't closed - there being no separate indirect cylinder. The water we were using was the water that circulated through the panels.

There are 2 panels, by the way, approx 1m wide x 2m high. These were sufficient for 6 people most of the time (maybe not 6 teenagers!)

Solar hot water panels would be a bonus certainly in the warmer month, your not going to generate enough electrical power to directly heat the water unless you spend €€€€€ on panels.

The hot water panes are cheap to run, basically all you are doing is pumping water and not using power to directly heat the water, the panel does that for you.

I used similar when living on Cyprus for domestic hot water and it worked very well indeed. A swimming pool will hold masses of latent heat so you want to look at a good cover for the pool too so as to trap heat when the pool is not used. A good cover will keep a pool warmer for days.

As you were a plumber for 45 years I'll leave it to you to apply your vast knowledge to the problem of closed loop heating and using a properly treated water in the closed loop to prevent rustiing!

Expanding on that a bit; You would probably need about 10 sq metres of panel to generate that much power together with a fairly meaty inverter. Also remember that solar panels only generate their rated power when pointing directly at the sun so they would need to be automatically orientating - probably quite expensive. You could reduce the amount of panel by using a bank of batteries. I'm no expert on this at all but in my limited experience (of solar panel generation on my boat) it quickly gets very expensive and complicated.

Closed loop is no problem apart from the cost of the extras you missed listing, the main problem is the tin cans under the ground.