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Our house only has electricity for heating/hot water. There's no option of mains gas. In theory i could have an oil system/ other heating system fitted, but it would cause so much disruption and i'm not sure if I would ever get my money back in saved costs.
So i have been thinking about solar for domestic hot water only. I think I would need a new tank, but after that the installation looks fairly simple and not too disruptive. BUT it has to make economic sense, and provide sufficient hot water, albeit I know there will need to be an electric back up.
I've looked into solar for electricity generation, but the payback is currently 15 years! And that is based on them not going wrong! So unfortunately that is too long for me.
So if anybody has solar for hot water only and is willing to share the good and the bad that would be appreciated!
I have it in a rented property. Got 2 panels on the roof. Im guessing a bit under 4m2 total area.
Only got electric so no central heating. Got a big tank about 1.5m tall with 2 immersions. In the winter solar does very little unless its very sunny. But in the summer it is brilliant. Im pretty sure the immersions hardly kick in. The panels will heat the full tank to 60 degress by midday.
The issue... Our system either has no safety cut off or its broken. It will, on the right day, almost boil the water. Ive seen readings of 95 degrees in the tank before.
But in summer even on cloudy days it will bring the whole tank up to about 35-40 degrees. Which gives the immersion less to do. Our electric bill for a 3 bed detached with no gas or oil in the summer is about 20 a month. Its about 80 in the winter with 3 electric heaters on a few hours a day whilst mostly using log burners for heat.
So yes it seems good though i didnt pay to install it. I would potentially look at putting a heat leak radiator into the coldest room in your house or in the garage as a drying room or something. Just so all the excess isnt wasted.
, but it would cause so much disruption and i’m not sure if I would ever get my money back in saved costs.
LPG instant gas water heater is I assume the cheapest and easiest solution - about £2-300 for the heater and less disruption than putting panels on your roof
I know its not what you asked for but not sure if you are aware of them - used on boats can provide some links if you want,
I've been thinking of something similar. We have a 250l hot water tank fed by the gas boiler with an immersion backup, but I've seen 1kw immersion heaters specially designed to work with PV panels. My thinking is I won't need a huge solar "array", 2kw max, and a fairly easy install. But......how easy is it to install another coil into a hot water tank? Is it even possible?
You can probably just link into the one you have but i suspect the controls will mean its just easier to get a new twin coil tank
We have best of both worlds. Solar electricity feeds the existing immersion heater and warms the water cylinder but only if we are not using the electricity elsewhere and we still get paid a generation fee.
the clever box of tricks is called an Immersun.
not as cheap as a painted radiator and some hose pipe but we will be turning the boiler off till October very shortly( 8kws system for family of 3)
The good news is that you are replacing the most expensive form of energy so the financials will be as good as they get. I've got it (flat plate) installed and during the summer/late spring/early autumn I can get a whole day of hot water for free. late autumn through to early spring it contributes a bit depending on the sunshine.
The solar will deliver about half your hot water requirements across the year so a 210 Litre cylinder raised from 10-65 degrees C requires (210 x 55)/858 = 13.5 kWh.
You'll get 365/2 * 13.5 = 2500kWh/annum from the system.
if you pay 15p/kWh for your electricity, you'll save £375/year. check your tariff and amend calcs as required.
You need to get quotes and see how that ties in with your payback expectations.
It's relatively maintenance free - check the solar system is pressured up every 6 months or so, top up as required. mines easily checked as the loft is floored and system accessible. it works - you can set your immersion heater timer to come on and hour before you need the water in the evening to 'top up' if required so you don't worry if the day has been dull.
We have a solar system, it has the central heating looped through it as well.
For a while it was the only supply of hot water we had, downsides are 5 in the house and the 3 females all love a bath. So it wasn't really cutting it on that front.
We now have the bathroom upstairs fed from the gas boiler and downstairs is from the solar.
It works for us.
I've had a solar water heater for nearly ten years. It thermosyphons so there are no pumps or anything to go wrong. It provides all our domestic hot water for 5-6 months and when not hot enough for a shower pre-heats water going into a second tank with a heating element. Over the year it provides at least 2/3 of our hot water, perhaps more now junior has left home.
Would I do it again? Not sure because you can now get heat-pump hot water tanks which save about the same but crucially save more in December and January when there's peak electricity demand and the solar panel only raises the temperature a few degrees (or not at all when there's snow on the panels).
Financially I originally calculated it would pay for itself in 11 years but given the increase in electricity prices it's a bit less.
Edukator where are you in France?
Potentially going to buy a place in Italy. Small place, but with all basic amenities.
A thinking of having a few cabins and using so<span style="font-size: 0.8rem;">lar for the hot water and showers. </span>
Pau, Alpin.
Lots of houses here in WA have a solar hot water system. Either a gas or electric back up with at least a 300l tank.