Solar water heating, how much??

mumof3girls

Was wondering where and what sort of prices you would be looking at on solar water heating??

Cardew

If you do a search on this forum(for solar hot water) you will find lots of posts on Solar HW.

To get a decent system it seems that £2,000 to £3,000 is the range you are looking at. Lots of cowboy firms will try for much more.

Estimates of savings per year are between £25 to £75. Don't believe anyone who claims much more than that - £50 -£60 is good.

So it makes no sense in 'money saving terms' but hey if you want to save the world!

woollyjumper

I did a 2 day DIY course through the local council and it cost me £1500 for the training and all the parts, and I now maintain the system myself.
It has been installed for 12 months and I think the saving are higher than the £75 stated due to the fact I am using an oil boiler to heat the water.
Even , so it is a long term to get your ROI and it does give you a feel good factor when having a warm shower that has been heated via your solar panels.
I will try and look back at our oil heating and compare to see what we have saved in the last 12 months.

annscullamus

I had a Solartwin panel fitted Feb 2005, and it has definitely saved me much more than £75 in calor gas water heating from my boiler. I used 32% less gas the first year and 37% less last year and I live on the Isle of Skye! From May to October I regularly turn off the hot water switch on the controls about 3 or 4 days in the week and the water heats up by about 20 degrees, so when it is switched back on the boiler has to do much less work. I have a thermometer in the kitchen and watch the temp go up on bright days, sunny days are a bonus. It has a solar pump, so no electricity at all, and to get the most out of it, it needs to have very cool tank after the morning bath's or showers! We love it!

Cardew

Regarding savings.

The average family uses 5,000 to 8,000kWh per year on Hot water.

A really good solar system might produce 50% of that - the further South in GB the better.

So we are talking of 2,500kWh to 4,000kWh pa and that would be better than most people achieve. Bear in mind that it will often produce more on Hot summer days than can be used; but you will get very little in the winter.

So if you have Gas or Economy 7 electricity - well you can do your own arithmetic.

With Calor gas or oil you will save more than with mains gas or economy 7 but still not enough to make things financially viable.

Not many people, who spend a lot of money on a system are objective about their savings. There is one knowledgeable person on this forum(Paul H?) who bought a house with a large 5 Mtr Sq solar system already fitted. He has done all the calculations and saves £60 a year. However he does all his own maintenance - changes anti-freeze etc

seaweasel

Geothermal heating is a lot cheaper AFAIK, you could also look into that.

Cardew

seaweasel wrote: »

Geothermal heating is a lot cheaper AFAIK, you could also look into that.

Cheaper? A system cost £15,000 t £20,000.

Geothermal heating provides heating for the Central Heating system. Solar water is just for Domestic Hot Water(ie from the taps)

See:
http://forums.moneysavingexpert.com/showthread.html?t=287944

annscullamus

With regards to maintenance - with the heating panel we have there is none. It is very simple, cold water is pumped in at the top and trickles over the panel - no anti freeze or the like - and is released into the top of the hot water tank.

It cost just over £2100, and we got a grant of 40% from the energy savings trust.

The full cost was around £1260, and was designed in Scotland, for our climate and light conditions.

Today, in the rain the tank was 19 degrees at midday, after morning use from the gas heater from 7.30am - 8.30am, and by 5pm the thermometer stood at 32.5 degrees, so when the timer came on at 5.30pm it had 12 degrees less work to do. This was a bad, to average day from April through to late September or early October.

It is the quality of the light which makes the pump work, and it can be heard whirring into action intermittently all day from the master bedroom, where it is fitted to the most Southerly roof.

The water heater is regularly switched off. It may take 10 years to pay back, but my Calor bills like it enormously, even Calor noticed the usage go down, and my monthly direct debit reduced by £16 spread over the year.

Do you need to see my bills?

Cardew

annscullamus wrote: »

With regards to maintenance - with the heating panel we have there is none. It is very simple, cold water is pumped in at the top and trickles over the panel - no anti freeze or the like - and is released into the top of the hot water tank.

It cost just over £2100, and we got a grant of 40% from the energy savings trust.

The full cost was around £1260, and was designed in Scotland, for our climate and light conditions.

Today, in the rain the tank was 19 degrees at midday, after morning use from the gas heater from 7.30am - 8.30am, and by 5pm the thermometer stood at 32.5 degrees, so when the timer came on at 5.30pm it had 12 degrees less work to do. This was a bad, to average day from April through to late September or early October.

It is the quality of the light which makes the pump work, and it can be heard whirring into action intermittently all day from the master bedroom, where it is fitted to the most Southerly roof.

The water heater is regularly switched off. It may take 10 years to pay back, but my Calor bills like it enormously, even Calor noticed the usage go down, and my monthly direct debit reduced by £16 spread over the year.

Do you need to see my bills?

I don't understand the overall point you are trying to make; is that solar panels make economic sense?

I doubt that the water that 'trickles over your panel' is the water that comes out from your taps; any more than the water heated in your calor boiler comes out of your taps. That water goes into a heat exchanger(in your tank) which heats the water in the tank.

So how is the water that 'trickles over your panel' on your roof prevented from freezing? Or is it not treated because the Isle of Skye has a mild climate? Certainly in most of Britain it would freeze.

Just some economics; and bear in mind that most of Britain do not get the huge grants available in Scotland.

If a system costs £1,260 people have to borrow that money at say 6%(if they are lucky) costing £75 a year. - or use savings with a compounded loss of interest. Then you start to pay back your £1,260!


If you are convinced that your system saves you £16 a month(£192 a year -even at the high price of Calor gas) and calculate that by the scientific method of looking at your Monthly DD! all I can say is that you must have the best and most efficient system in GB, the Isle of Skye must have a far better climate than I remember, and you must use prodigious quantities of Hot water.

Have you never considered changing to an Economy 7 electric tariff to heat your water at night?

I am afraid to say it is typical of the claims made by the enthusiasts who have paid money out for a system and feel they need to justify their expenditure.

Anyway the point of this thread is to give costs for Mr and Mrs Average in UK and most people will pay £2,000 to £3,000 and annual savings will be in the region of £50-£75 and it makes no sense in economic terms.

If you believe that it is a good thing for yourself - so be it.

annscullamus

Dear Cardew,

In Scotland we do get bigger grants - so why not use them - it istherefore part of my economics. See the manufacturer for the system - in winter when the solar pump does not pump, no water flows - no freezing.
https://www.solartwin.com or co.uk is the name. I paid cash, and did not borrow. Like anything else if we saved every penny we spent on chocolate, think of the compounded interest after 10 years.....................
The point is, it raises the temp of my water tank and I use less Calor Gas.

Cardew

annscullamus wrote: »

Dear Cardew,

In Scotland we do get bigger grants - so why not use them - it istherefore part of my economics. See the manufacturer for the system - in winter when the solar pump does not pump, no water flows - no freezing.
https://www.solartwin.com or co.uk is the name. I paid cash, and did not borrow. Like anything else if we saved every penny we spent on chocolate, think of the compounded interest after 10 years.....................
The point is, it raises the temp of my water tank and I use less Calor Gas.

Dear annscullamus,
This thread was(and is) about a general query on costs for Solar Water heating.

However thank you for your link and I have read the site with interest. In fact I have to say it is a far better site than many I have read; still full of irrelevant information for most people but a couple of interesting facts buried away.

Just a couple of points discussed earlier.

It does not have a heat exchanger; the warmer water goes straight into the tank. The water on the roof is simply allowed to freeze and nothing gets pumped.

It is also a much smaller system than most domestic installations. 2.8sq mtr – most are 4 or 5 sq mtr

The website says systems will be installed from £3,399 for a single 2.8 sq mtr panel - so you got a bargain.

However when it comes to savings, buried away is a most revealing statement, namely:

"Independently tested, Solartwin delivered 1000 kWh (3.6 GJ) of clean green energy as solar hot water a year in UK."

That is quite normal for a small system. I would further suggest that, given the latitude and weather the Isle of Skye, will be one of the worst places in UK for Solar. In fact to confirm this I rang the firm. They say “in the North of Scotland you would expect a saving of 800kWh and in the South West of England 1,300kWh – an average of 1,000kWh."

Now for those of us with gas that 1,000kWh will save us approx £25 a year, approx £30 for Economy 7, with oil approx £40 a year and with Calor gas approx £50 a year.

So for a system costing from £3,399 – with a 5 year guarantee - they claim independent tests could save on average £25 to £50 pa – I think that is an honest claim.

By any form of financial logic to spend £3,400 to save £25 to £50 is a complete nonsense.

You can believe whatever you wish about the merits of your system and use whatever economic logic you feel suits your case; and the chocolate analogy speaks volumes.

I have to say your posts are quite typical of the self delusion those with solar panels seem to suffer. Your savings are likely to be £40 a year, yet you have convinced yourself that £192 is your savings.

I am sorry to be so blunt but such misleading information posted as advice on this Board should not go unchallenged.