smart51
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| posted on 23/2/08 at 04:42 PM |
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Solar Hot Water
Anyone know about solar hot water? My boiler has blown up. Whilst British Gas will probably patch it up, it generally sounds ill and will pop for
good before long. I had a guy in today to quote for solar hot water. They only sell the modern evacuated tubes and together with a tank fitted to
the loft, plus all the piping etc, he wants £7100. Thats after the 25% discount for having their sign on the front of the house for 8 weeks as
advertising. Is that a lot? I was expecting £5000 ish.
He also wants £3000 to fit a new boiler, which also sounds a lot.
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twybrow
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| posted on 23/2/08 at 04:45 PM |
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You can get a grant for this type of work I believe...?
You need to be sure you are not moving for the next 20 years, or else it is unlikely to pay for itself.
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zilspeed
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| posted on 23/2/08 at 04:45 PM |
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Much as the theory of it all really grabs me, I'm afraid it wouldn't be me at that sort of price.
How long would be payback be ?
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smart51
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| posted on 23/2/08 at 04:55 PM |
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The evacuated tubes don't need direct sunlight, just light. so they provide most of your hot water in the winter and all of it in the summer.
Work out how much you spend of Gas and work out your payback period.
I'm told that a solar system adds 9 - 10% to your house value, not that we're planning to move, but if you're a light gas user
payback may be quicker if you move house.
I know that salesmen are full of it but one thing that he said was all bull. He reckoned that a full tank of 95° hot water took 1 hour on a cloudy
winter day and 20 minutes on a sunny summer day. From his literature and common sense, his solar panel will heat the tank by 10°C per hour in full
sun and maybe 7° when cloudy.
[Edited on 23-2-2008 by smart51]
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bob tatt
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| posted on 23/2/08 at 05:01 PM |
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sorry to have to say it but solar hot water is not cheap and the pay back time is about 12 to 15 years depending on size of house number of bathrooms
etc good selling point if you ever move but it remains to be seen whether or not people will pay a premium for it as yet the evacuated tubes are
slihjtly more efficent than the panel type but are more prone to problems as in broken seals allowing the gas to escape and did he ssay weather it was
a drain back system or constantly filled as the drain back systems can be a bit noisy. the three grand for doing the boiler sounds a bit excessive if
you can tell me what this included including size and model of boiler i shoiuld be able to give you a good idea on that one have a look on the
worcester bosch web site and search for your local green skies installer they are offering preety good grants at the moment
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MikeR
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| posted on 23/2/08 at 05:02 PM |
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Contact these people & see what they say. They did my cavity wall insulation and seemed pretty good.
Even explained why solar wouldn't be good for me. (i already knew, but it was nice having someone NOT sell me something).
http://www.rockwarm.co.uk/index.php
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billynomates
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| posted on 23/2/08 at 05:04 PM |
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Personally, I wouldn't deal with a company that are prepared to knock £1800 off the price for just putting a sign in the garden. They obviously
are employing well recognised sales techniques.
What about you ring thme back and tell them they can have a bigger sign, for 32 weeks, but you want the system installed for £12.47.
On a serious note though, they've probably got quite a lot of profit margin left at £7100. Why not ring them back and say £7000 with the boiler
and you've got the job. They can only say no.
3k is hefty for the boiler swap - assuming it's a straightforward change over.
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mookaloid
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| posted on 23/2/08 at 05:10 PM |
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I manage properties for a living and I generally pay £1500 for a boiler swap and that's for a Worcester Bosch which is generally considered one
of the best.
No idea on the solar stuff
Cheers
Mark
"That thing you're thinking - it wont be that."
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Jasper
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| posted on 23/2/08 at 05:15 PM |
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Try and get a recommendation from a friend of a good local plumber - I would agree that £1500 is about right for a regular boiler swap - make sure
it's a decent make.
If you're not living life on the edge you're taking up too much room.
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thunderace
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| posted on 23/2/08 at 05:22 PM |
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i have designed one to heat my pool in spain it is 100% solar powerd solar panel to spin the pump and copper micibore painted mat black to take the
heat coiled up in an insulated box whit a glass lid to keep the heat in ,it was very easy to make and works great.
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Andy S
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| posted on 23/2/08 at 05:26 PM |
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Payback periods - the real calculation
Put the £7100 in a high interest account and work out the annual interest.
Deduct the hot water cost that you would incurr using your existing gas system.
I am in no doubt that year on year the money in your account will grow.
For the Solar
The £7100 is gone and you have service agreements and the annual running costs of the pumps and controls that are electrically operated. + the gas and
electrical use when the solar cannot perform effectively honestly that is 40% of the time.
They dont work at night and in the winter our daylight hours are short.
Give the salesman the calculation and ask him the payback period.
How often does the pumped medium need replacing? - what protects from legionella?
Is your loft capable of holding the weight of the cylinder and whats the storage capacity?
Andrew
Ex technical manager of one of the worlds leading manufacturer of renewable heating solutions
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tegwin
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| posted on 23/2/08 at 05:29 PM |
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Have you considered Air or ground source heatpumps instead?
I have just finished a two year project involving several of these...
U2U me if you want a load of informaiton...I cant be arsed to type it in if heatpumps are not of interest to you
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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Guinness
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| posted on 23/2/08 at 05:36 PM |
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http://www.navitron.org.uk/pricelist.htm
"Deluxe Solar Kit
20tube panel; pitched roof mounting kit; twin coil hot water cylinder (up to172litre double insulated, Grade3 with Grade2 base); TDC3 Solar
controller; Circulation Pump + isolation valves; anti-syphoning valve; pressurised system kit; 10m armaflex HT high temperature; antifreeze
£1122"
Then find a plumber who wants less than 6K to fit it.
Payback time is obviously dependent on the amount of initial expenditure.
HTH
Mike
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Andy S
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| posted on 23/2/08 at 05:40 PM |
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Heatpumps LOL
Not for an existing property
The Geo costs alone kill them never mind hardware costs and service up-keep of the compressors - and then there is the low grade heat produced needing
underfloor heating and electric immersion heating for hot water.
COP needs to be 7 at least before they are viable and then need a 3-4 year between service life.
Put the £15K in a high interest account etc etc.
Andrew
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tegwin
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| posted on 23/2/08 at 05:55 PM |
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LOL....
We just fitted an air source heatpump to a very large radiator system and hot water system....
Total heat output 23Kw, @50 degrees flow temperature....
Granted, it cost £12000....But if you wanted a much smaller heat output then the prices drop rapidly!
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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tks
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| posted on 23/2/08 at 06:04 PM |
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quote:
Originally posted by smart51
Anyone know about solar hot water? My boiler has blown up. Whilst British Gas will probably patch it up, it generally sounds ill and will pop for
good before long. I had a guy in today to quote for solar hot water. They only sell the modern evacuated tubes and together with a tank fitted to
the loft, plus all the piping etc, he wants £7100. Thats after the 25% discount for having their sign on the front of the house for 8 weeks as
advertising. Is that a lot? I was expecting £5000 ish.
He also wants £3000 to fit a new boiler, which also sounds a lot.
Don't do it, you know it doesn't make sense those figures...
Trust your feelings..
4500Euro fit change a boiler...what a hell of a boiler that needs to be!!
Tks
The above comments are always meant to be from the above persons perspective.
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tegwin
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| posted on 23/2/08 at 06:16 PM |
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He has a point...
Its going to take us about 15 years to make the machine pay for its self..
But if you cant have gas, and your electricity supply is limited to 60A...there isnt much you can do if you want 20Kw of heat...
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Would the last person who leaves the country please switch off the lights and close the door!
www.verticalhorizonsmedia.tv
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coozer
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| posted on 23/2/08 at 06:33 PM |
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Just dig a hole in the garden about 300m deep and drop some a loop of pipe down it and pump the heat from underground....
1972 V8 Jago
1980 Z750
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smart51
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| posted on 23/2/08 at 06:36 PM |
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quote:
Originally posted by Andy S
Put the £7100 in a high interest account and work out the annual interest.
Deduct the hot water cost that you would incurr using your existing gas system.
£7100 @ 5% interest, less tax = £24 per month.
Less 1/2 of monthly gas bill = not a lot.
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cidersurfer
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| posted on 23/2/08 at 06:56 PM |
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There was a programme on Westcountry TV about these last night. They were doing a Watchdog type programme on a scamming company called Ultimate
Energy, they were originally called something else and were shut down for dodgy dealing but re-invented themselves and are at it again. Basically,
lying about the efficiencies of solar water heating in their sales pitch. They had an independent expert witness who claimed that these systems will
never pay for themselves in the UK and that you're better off topping up your loft lagging, etc... They were charging about £10k for a single
panel system, I think the expert claimed it should cost no more than £4.5k!
A replacement combi boiler should cost £2200 max fitted.
shimming solid lifters is a job for a friend...
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cidersurfer
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| posted on 23/2/08 at 07:06 PM |
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Not Westcountry TV but BBC South West, there's a link
BBC
shimming solid lifters is a job for a friend...
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smart51
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| posted on 23/2/08 at 07:12 PM |
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I've just done a payback calculation based on saving 1/4 of my gas bill and based on gas prices rising at 5% per year. 61 years. I have an
environmental conscience but not that much.
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britishtrident
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| posted on 23/2/08 at 07:17 PM |
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In the average UK winter day it is not viable get high grade heat from solar energy alone.
If used for domestic hot water the temperature of stored water must be kept above high enough at all points in the storage tank and system or you
run into the danger of water born bugs eg Legionella, E-coli, Cryptosporidium.
Legionella is the bigest threat in a domestic hot water system .
* 70 to 80 °C (158 to 176 °F) - Disinfection range
* At 66 °C (151 °F) - Legionellae die within 2 minutes
* At 60 °C (140 °F) - Legionellae die within 32 minutes
* At 55 °C (131 °F) - Legionellae die within 5 to 6 hours
* 50 to 55 °C (122 to 131 °F) - They can survive but do not multiply
* 20 to 50 °C (68 to 122 °F)- Legionellae growth range
* 35 to 46 °C (95 to 115 °F) - Ideal growth range
* Below 20 °C (68 °F) - Legionellae can survive but are dormant.
Unless the hot water temperature is over 65c at all points in the storage tank 65c and at point of use the water temperature reaches >60c within
1 minute it is a potential major threat to your health.
With legionella the danger is inhaling a tiny infectect water droplet, in a domestic situation this could be from a shower
http://en.wikipedia.org/wiki/Legionaires_disease
[Edited on 23/2/08 by britishtrident]
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Andy S
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| posted on 23/2/08 at 07:20 PM |
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Water only remember - Not heating not cooking.
quote:
Originally posted by smart51
quote:
Originally posted by Andy S
Put the £7100 in a high interest account and work out the annual interest.
Deduct the hot water cost that you would incurr using your existing gas system.
£7100 @ 5% interest, less tax = £24 per month.
Less 1/2 of monthly gas bill = not a lot.
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Bob C
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| posted on 23/2/08 at 07:36 PM |
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A locostbuilders thread & no-one has mentioned DIY.....!!!
The evacuated tube panels alone would only be a few hundred quid. (plenty on ebay)
Swop the cylinder for one with an extra coil at the bottom & have a closed circuit for the solar (keep the bugs sealed inside....)
The long payback woes are for photovoltaics, thermal is a lot cheaper & more efficient. If the cost is 1k£ + some effort, it starts to look rather
more promising.
I'm thinking about it for an unused section of wall at the south side of my house.....
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