Solar To Heat Water Spain

firefox1956

This is what I want to do.........
I have a 50 litre hot water tank that has a 1kw electric heating element.
The tank electrics are just on a standard plug.
What I want to do is heat the water in the tank using a solar panel/s.
How do I do it easily myself ??
I don't want to involve any surplus generation going on grid.
The installation will be located in Spain.
Any ideas, links etc would be gratefully received.
TIA

EricMears

If you only want to heat water, thermal solar would probably be better than PV.

firefox1956

EricMears wrote: »

If you only want to heat water, thermal solar would probably be better than PV.

Not an option for me as the huge ugly units are way, way too big for my needs.

EricMears

firefox1956 wrote: »

Not an option for me as the huge ugly units are way, way too big for my needs.

I don't have thermal solar myself but understand that modern units fit neatly on a roof taking up far less room than PV panels would need. As for 'ugly', it's an argument that is often directed towards PV; I don't agree with that and have often pointed out that it's not usually possible to see your own roof so does it really matter if you consider them ugly.

unforeseen

Being Spain, the roof tends to be accessible and used for various things

zeupater

Hi

I take it that you're looking at a stand-alone system, if so then the size of the panels would be limited by ...

Energy to heat 50litres (from cold to ~70C = ~3kWh)
Daily water consumption
Heatloss (?insulated?)
The maximum power you can absorb (currently 1kW)

... and, of course, orientation location etc .... then there's plumbing it in and what else you'll need to heat the DHW when it's been cloudy for longer than your solar heating store can provide for ...

Probably the place to start is to assess how much hot water you'll need and work back from there, but 50litres isn't much ...

HTH
Z

zeupater

firefox1956 wrote: »

Not an option for me as the huge ugly units are way, way too big for my needs.

Hi

Are you talking about the integrated thermal systems where there's either panels or tubes with a water store at the top? ... you see plenty of these, particularly around the Med ... they make quite a decent stand-alone solution for providing hot water!

HTH
Z

firefox1956

zeupater wrote: »

Hi

Are you talking about the integrated thermal systems where there's either panels or tubes with a water store at the top? ... you see plenty of these, particularly around the Med ... they make quite a decent stand-alone solution for providing how water!

HTH
Z

Yes, & they are huge horrible looking things !!

zeupater

firefox1956 wrote: »

Yes, & they are huge horrible looking things !!

Hi

Okay, so what do you think about standard PV panels? ... to heat water you'll need more square meters of PV than you would solar thermal, whether plate or vacuum tube ...

Have you thought about the amount of water you'll want to heat on a daily basis yet? ... everything depends on you working that out as no-one can provide any really useful guidance/insight until we've got a clue as to how much energy you'll need!

HTH
Z

silverwhistle

Your set up up may well be like the flat I rented in Italy where hot water was supplied from a tank above the bath heated by an immersion. A small heater given that the total load for the flat maxed out at 3kW (actual 3.3), and would trip the smart meter if you went above that. No English electric kettle!

It's a shame you couldn't use a 12 volt immersion (they are available) and direct from a couple of PV panels with no inverter or similar costs and no complicated plumbing changes. I imagine you'd want to use mains to top up with during certain seasons. If you had a UK type tank with two inputs it might be possible.

Those more technical than myself might see other objections.

EricMears

silverwhistle wrote: »

....
It's a shame you couldn't use a 12 volt immersion (they are available) and direct from a couple of PV panels with no inverter or similar costs and no complicated plumbing changes. . .

Those more technical than myself might see other objections.

One quick 'objection'. The DC feeds to my inverters are from 8 panels in series and tend to be around the 240v area. A single panel is therefore likely to be around 30V which would make rather a mess of a 12V element.