Siting of panels for solar water heating

In message , Curious writes

"Will" wrote: We moved into our two storey, reconstituted stone-built, pitched-roof house in April.
We decided early on to get as much of our energy as possible from renewables.
A couple of weeks ago we signed up for a solar heating system. I've looked at a few and this seems like a very good system.
Watchdog 'did' the solar energy industry on BBC 1 last Tuesday evening. Their conclusions were that there a lot of rogue companies, the estimates for equipment and installation are very inflated (�12,000 in one case for a non-working system), the claimed energy benefits are often very exaggerated, the salesmen talk a lot of dishonest rubbish, and a lot of properties are not suitable. My understanding is that the panels need to be mounted on a south-facing aspect. Got a long bargepole?
We also had a discussion in here following my father having signed up to

such a system
This was �7000
Say a payback period of 10 years being reasonable, it has to save �700 / year to pay itself back. Given that it's only saving (optimistically ) 70% of hot water, not central heating or gas for cooking, it's patently impossible for it to be viable
-- geoff

In message , Mary Fisher writes

"Will" wrote in message
The alternative, according to the surveyor, would be double the number of panels with half on the east pitch and the other on the west.
That would make it very expensive.

Yes, but not double the price. Maybe about a third more ?

We only looked into the system because we had a directly south facing pitched roof, if we'd not had that we wouldn't have considered it.

It's not without advantages. It does mean you can get more power earlier and later in the day, and more or less as much in the middle.
Cheers, J/. -- John Beardmore

In message , Eric Sears writes

Of course, if the panels were for space heating, you might want the greatest input in the morning, in which case the east facing roof might be better. There are a number of factors to consider.
Like ...

what time the sun rises in winter, how big a thermal store you would need to store sufficient heat overnight
it's just not very realistic for heating
-- geoff

In message , Mary Fisher writes

"Will" wrote in message
We moved into our two storey, reconstituted stone-built, pitched-roof house in April.
We decided early on to get as much of our energy as possible from renewables.
A couple of weeks ago we signed up for a solar heating system. I've looked at a few and this seems like a very good system.
The marketing wonk who visited us (who had obviously been in the pub first) declared that our directly west-facing roof would be perfectly adequate to site the panels. It is a very clear prospect as it faces a flat field, and there are no trees in the line of sight.
However, when their surveyor came to measure up he said that the west-facing roof was inadequate and the panels would have to be sited on the gable-end wall (facing south).
From our experience with our very good south-facing solar panel I'd say that the surveyor was right. The sun's rays will only be falling on a west-facing panel for part of the day and in winter they'll be too low to be effective.

Yes. Facing due west won't be great, but keep in mind that if you capture heat towards the evening, it won't have to be stored long before a typical family will use it.
We once inspected a system, and data logged a collector that faces 45 degrees west of south in summer.
To quote our report, "the temperature of the pipe from the solar panel shows a rise of about 5.25�C per hour on the 25th, starting at around 9:00 and continuing until around 19:00".
(The 25th was one of the few sunny days !)
Cheers, J/. -- John Beardmore

In message , SJC writes

Solar thermal panels for space heating is one of the ways we can save lots of fossil fuels in the future.
Sorry, this is UK.d-i-y, not alt.bad jokes

as practical, as they say, as a chocolate teapot
where are you going to get meaningful heat from at 7am ?
the best source, I would suggest, would be the hot air emanating from the sales rep
-- geoff

In message , Mary Fisher writes

"Joe Fischer" wrote in message
The roof pitch should be ignored, and the panels mounted so they get the most direct sun, but sometimes that makes an unsightly installation.
I disagree that solar water heating panels are unsightly, they look like a large Velux window, flat and dark.
It could only be an improvement around Leeds

-- geoff

In message , MarkK writes

"Peter Crosland" wrote in message However, when their surveyor came to measure up he said that the west-facing roof was inadequate and the panels would have to be sited on the gable-end wall (facing south).
Have you checked with the local planners that you don't need their permission? Quite a lot of people get caught out with this.
Good point. You can normally fit panels to the roof without PP if they don't protrude more than about 100mm,

I thought it was 80mm, (even in national parks ?), as long as you aren't in a conservation area or on a listed building ?

but sticking them on a gable end at an angle probably will require PP.

Yes - and the planners I've asked really hate it ! :)

To be safe it's best to get a letter from the local planning dept even if no PP is required, to help speed the inevitable solicitor's queries when the time comes to sell. I did for mine, in fact I delayed placing my order until it was in my hands.

Hmmm... I've never heard of such queries, but no doubt it's the kind of thing solicitors live for...
Cheers, J/. -- John Beardmore

On Thu, 16 Nov 2006 20:30:21 -0000, "Curious" wrote:
Good. They should look at all renewables.
Was this solar PV, or solar HWS systems, OOI ?

Watchdog 'did' the solar energy industry on BBC 1 last Tuesday evening. Their conclusions were that there a lot of rogue companies, the estimates for equipment and installation are very inflated (�12,000 in one case for a non-working system), the claimed energy benefits are often very exaggerated, the salesmen talk a lot of dishonest rubbish, and a lot of properties are not suitable. My understanding is that the panels need to be mounted on a south-facing aspect. Got a long bargepole?

You seem to be so sure of yourself, but you are so wrong. Look up fluid source heat pumps with solar...get a clue.
"raden" wrote in message

In message , SJC writes Solar thermal panels for space heating is one of the ways we can save lots of fossil fuels in the future.
Sorry, this is UK.d-i-y, not alt.bad jokes
as practical, as they say, as a chocolate teapot
where are you going to get meaningful heat from at 7am ?
the best source, I would suggest, would be the hot air emanating from the sales rep
-- geoff

On Fri, 17 Nov 2006 22:12:22 GMT, raden wrote:
Well, having done a few quick calcs, I tend to agree, unless you had a HUGE heating panel to get it active the next morning.
However, I would be interested in your calcs and figures, as you seem to feel strongly about this <G>

Like ...
what time the sun rises in winter, how big a thermal store you would need to store sufficient heat overnight
it's just not very realistic for heating

In uk.d-i-y raden wrote:

In message , Eric Sears phoneme@025379386.for.email.address> writes Of course, if the panels were for space heating, you might want the greatest input in the morning, in which case the east facing roof might be better. There are a number of factors to consider.
Like ...
what time the sun rises in winter, how big a thermal store you would need to store sufficient heat overnight
it's just not very realistic for heating

Well...
I think the usual assumption is that the building will have significant thermal mass internally, in the form of an insulated concrete slab, or something.

On Sat, OldNick wrote:

Well, having done a few quick calcs, I tend to agree, unless you had a HUGE heating panel to get it active the next morning.

If solar heat is wanted at 0700 in a certain room, an east facing window wall might be better than any panels. There is nothing lower cost than ordinary window glass. My only kitchen outside wall faces SSW, and in the afternoon the window makes almost heat as a 1000 watt baseboard heater, and the window is a little over a square meter.
With fuel prices apparently retaining the high prices, there could be a huge market for things like solar air heaters for inside windows, just a decorative black pattern or simple venetian blinds black on one side and white on the other.
Many heating panels and heaters are hyped as radiant heat feels warmer even if the air is not as warm, and the same goes for sunshine, except sunshine is free (when it shines), and it can heat the air just as well as the electric panels. A window can provide about 5 times the energy as PV panels of the same area, and that is a lot, and it also makes PV seem not all that expensive considering what electricity can do, it is cheap grid power that makes PV seem expensive.
Joe Fischer

On Sat, 18 Nov 2006 08:09:03 +0800, OldNick wrote:
Actually I am not sure I _do_ agree. Still interested in your basis.

On Fri, 17 Nov 2006 22:12:22 GMT, raden wrote:
Well, having done a few quick calcs, I tend to agree, unless you had a HUGE heating panel to get it active the next morning.
However, I would be interested in your calcs and figures, as you seem to feel strongly about this <G
Like ...
what time the sun rises in winter, how big a thermal store you would need to store sufficient heat overnight
it's just not very realistic for heating

In message , OldNick writes

On Fri, 17 Nov 2006 22:12:22 GMT, raden wrote:
Well, having done a few quick calcs, I tend to agree, unless you had a HUGE heating panel to get it active the next morning.
However, I would be interested in your calcs and figures, as you seem to feel strongly about this <G

(Look ... a contextual reply - the post has a chance to flow)
I have just had a run in with a company who ripped off my parents. Having just done a "fag packet" response, they freely admitted that solar central heating is a non starter for the reasons I stated below (which, if you hadn't top posted would have been in the correct place to quote)
I haven't done any detailed calcs, but they obviously have

Like ...
what time the sun rises in winter, how big a thermal store you would need to store sufficient heat overnight
it's just not very realistic for heating

-- geoff

In message , Ian Stirling writes

In uk.d-i-y raden wrote: In message , Eric Sears phoneme@025379386.for.email.address> writes Of course, if the panels were for space heating, you might want the greatest input in the morning, in which case the east facing roof might be better. There are a number of factors to consider.
Like ...
what time the sun rises in winter, how big a thermal store you would need to store sufficient heat overnight
it's just not very realistic for heating
Well...
I think the usual assumption is that the building will have significant thermal mass internally, in the form of an insulated concrete slab, or something.

Possibly not very comforting at 7 am in the morning in december
-- geoff