Solar heating – worth it??

Not long moved into a house and it needs a bit of work.

Hot water only supplied by an immersion heater and the tank needs moved, boiler only heats the central heating.

So i could do the easy thing and slap in a combi and hoof out the hot water tank, but I was thinking the boiler is in not bad nick so why not consider solar heating for the hot water topped up by an immersion when required.

Living in the south of scotland solar heating does not spring to mind as an option but I see quite a few houses with it. My mate in London swears by it.

Discuss.

Worth it? No. Next question…

Worth it ? Yes if you’re in for the long haul. We’ve had it in for over 20 years. Free hot water 4-5 months of the year, works ok bright spring/autumn days, no use on days like this !

Really depends on the size of your house and what your gonna use it for…really expensive to have decent solar installed BUT decent solar will work with little sunlight and can heat your whole house.

Thought about geothermic? Again expensive to install BUT repays within 4 years.

Depends if your trying to cut bils or be greener… i’ve managed to cut my leccy to less than £20 a month for a 3 bed semi just by greener options and insulation….. Heating your house however is the money burner… good curtains are better and give better returns than double glazing

Get on the interweb loads of free info from your local council.

From what I have read a solar hot water system just about repays its cost over its life time (at current energy costs), so don’t do it for cost saving.

To lessen the use of an immersion heater, with a kit like this one it would seem churlish not too.

Should pay for itself before too long (few years, less than 10 I would guess)

My parents had a couple of solar panels – in summer they required no extra water heating unless 2 baths were taken in a day. Even in winter (in Scotland) they got about 8 degrees C rise in the water at a minimum- so less energy to get a bathfull of hot water. Capital outlay was repaid in about 10 yrs

No. We spent quite a lot of money on ours and it’s a fairly complex computer controlled system. It only put heat into the tank on a sunny day in summer, and even that wasn’t huge.

DO NOT believe claims that they work on cloudy days or in winter. Just checked the temperature in our panels and it’s showing 8 degrees. It’s 4C outside, and I doubt the water temperature is much lower than 8-10C anyway.

It may have some value in acting as a pre-heater for cold water coming into the house, but besides that don’t bother. I can only recall seeing the computer showing the pump running once this winter.

Flaperon – our incoming water is about 2-3 degrees at this time of year.

My parents got a useful preheat out of theirs in a scpttish winter – no question.

Just an opinion but it will pay it’s way over it’s lifetime at current prices. Things could get worse on the energy market and an alternate source of energy may be a benefit. It wasn’t that long ago when oil and gas preices were silly that people were buying wood stoves to provide cheap/free heating.

I am a building service design consulatant and i design all this type of stuff for a living. Photovoltaic, solar heating, wind turbines, biomass boilers etc etc.

I would install any of it on my own house. you wont get pay back. I dont know what the other person means by payback of 4 years? thats rubbish. The install caost would be about 3-5k depending on the house size. Your gas bill is prob about 600 for a 3k installation or 1200 for a 5k installation. Only about 1/4 to a 1/3 of that gas used would be for hot water. Therefore the payback is far longer. then you have to consider the additonal maitenance these systems need. When you add it up not worth it.

Wind turbines and Photovoltaics are far worse than that.

Dont get me wrong it is sustainable and does help the environment but from a purley cost point of view not worth it.

the construction of solar panels is about as far from being green as you can get. incredibly harsh chemicals such as flourine are used to clean the panels, these are then caught in a chamber and buried under the ground.
but please buy solar panels and flat screens so my employers get more orders and i keep my job. ta.

MrKrabbs – I take it you mean photovoltaic? Water heating solar panels are just plumbing

Second what bradders said:
Last summer pinned down our friend who’s a plumber, very good and open minded and one of my most respected friends. He’d always dissed it so we asked why.
His back-of-envelope calculations worked out that a *massive* overcalculation would put our heating oil use for hot water at £250/year. We’d have to spend several thousands getting the cells put in plus heat expansion tank AND regular servicing of units ( don’t they use antifreeze in them somewhere?) and in his experience they can get frost damaged very easily so only last a few years. He concluded simply not worth it by a mile.
Q

For hot water there is a lot of advice and economical kit about from China these days. The Chinese are the worlds biggest solar thetmal installers, and they manufacture the big magority of evacuated tubes. Companies like Navitron in the UK import this stuff and sell mostly to DIY’ers. You can put a couple of square meters of evacuated tubes on your roof for a few hundred quid if you do it yourself.

Saying this I haven’t taken the complete plunge myself yet, but I did install a 300 Litre solar thermal tank when I replaced my normal hot water tank eighteen months ago. That’s part of the job, ready and waiting for the rest, I just need to get it sorted.

As far as financial payback is concerned. Thats’ something of an academic question for many. Why expect a financial payback at all? (but you should get one if you DIY). That “payback” policy is what’s put us in the mess we are in, because fossil fuel is many times too cheap. (Our children will recieve the payback though..). “Payback” from your installation is your own satisfaction knowing you are doing a bit to help..

As I said ^^, we’ve had it for 20+ years, installed cost was £2000 in 1987. Maintenance – what’s that ? I’ve had an engineer out once in all that time, and that was planned work for a house extension. I’m now looking at a wood pellet burner to supplement/replace the oil boiler. I’m no tree hugger – this stuff just seems obvious to me.

If you go for the more efficient type of panels (evacuated tube rather than flat panels)and they’re well placed, then 70% of your hot water should be a reasonable expectation. only on heavily cloudy days (& of course foggy ones)should it be inactive,although if you put enough panels on your roof even a day like those would do it,but then the problem is what to do with all that heat when the sun comes out (i’ve seen 167 degrees C on the panels in the summer

A friend made a solar panel by painting a radiator matt black, putting it i na wooden frame with glass on top.

Works a treat, he either gets hot water or uses less gass in winter.

He saves approx a 3rd on his gas bill.

His house is super insulated with wood burners etc.. etc..

at the end of the day UK house design is not fit for function in our climate.

As mentioned by mountaincarrot, Navitron is the place to go. The evacuated tubes are far more efficient than the traditional flat panel design and a system doesn’t cost as much as you think. Here are some of their DIY systems and a link to their excellent forums where you will get far better advice than here.