Solar Panal info req for domestic use

On Sun, 27 Jan 2008 11:15:27 +0000 someone who may be Andy Hall wrote this:-

Reasons for installing them have been explained before. The fact that some reject these reasons does not make them invalid, no matter how much some huff and puff.

Reply to
David Hansen
Loading thread data ...

On Sun, 27 Jan 2008 11:30:59 +0000 someone who may be AJH wrote this:-

It is certainly better to control the boiler from the solar controller. However, this means even more work and thus pushes the cost of a non-DIY installation higher.

Reply to
David Hansen

On Sun, 27 Jan 2008 10:48:48 +0000 someone who may be Mike P wrote this:-

Possibly partly correct. Some types of solar collector do not need direct sunlight to produce usable heat.

40% antifreeze and 60% water is more than adequate for the UK.
Reply to
David Hansen

On Sun, 27 Jan 2008 11:21:09 +0000 someone who may be Mike P wrote this:-

There are a variety of grants, depending on which country he lives in and whether the council have additional schemes. However, I doubt if anyone could get a full grant for a solar system.

Particularly in England the grant scheme is a mess and one may wonder whether this is accidental or deliberate.

Reply to
David Hansen

Why? Thermal solar panels don't need direct sunlight to work, you get more energy collected on bright sunny days but you stiill get some on dull overcast ones. Any decent system will circulate a antifreeze mixture so you don't have to drain it down in the winter...

Reply to
Dave Liquorice

OK.

If after discussion, it's decided to try to cancel the idea, then it could be worth making contact with them as well. There is the various consumer credit legislation that may be helpful, and there may also be avenues related to Distance Selling Regulations, although I believe there are rules there based around who contacted who and where the selling was done. In all of these, time is probably of the essence. The Citizens Advice Bureau are worth contacting, as is the Consumer Direct helpline. This kind of stuff is standard fare for them.

Reply to
Andy Hall

There's no huff and puff.

Please answer the question.

If it's not feel good or look good and isn't payback, what is it?

Reply to
Andy Hall

Yes, but they have validity outside pure cost benefit.

If you want to salve your conscience, a priest is cheaper.

Reply to
The Natural Philosopher

Te sky is too cold.

The exterior temperature? Solar panels work on the

Exactly. Something that is in such short supply in winter, that peopl need vitamin supplements..

On a sunny winters day, my room that has been warmed up by the boiler, simply needs the curtrinsns drawing back to absorb far more sunlight than a stupid panel on the roof.

Why not use curtains?

Lord. All this cost an complexity and heavy use of energy to produce less energy than the things took to make.

It reminds me of the 'we will never run out of oil' brigade. True, but when it takes more energy to get it out of the ground than is released by burning it, you do end up with some absurd economics.

Not something *you* would be bothered by, mind you.

>
Reply to
The Natural Philosopher

No solar collector needs direct sunlight to proiduce useable heat. In pathetically small quantities.

As opposed to merely *rather* pathetically small quantities.

The most efficient way to collect it is a black carpet in a triple glazed room.

Reply to
The Natural Philosopher

Personal abuse, excellent.

Reply to
Steve Firth

For most people, that will be the only measure. For a few people, energy payback might be a consideration, but photo- voltaics really struggle to produce more energy during their lifetime than they consume in manufacture, so there's no big win there.

For a really few geeks like me, I'll pay extra just for my own opportunity to play with the technology. E.g. I invested in a condensing boiler long before they were mandatory and when they were at a price premium, because the technology interested me and I wanted to try designing a heating system to make good use of one (which I did).

If I had a south facing roof, I would be interested in playing with some type of solar energy project on the same basis. However, with my roof ridge running north-south so it's never going to work well, and needing scaffolding in my neighbour's garden, and the outlay (even DIY'ed) with no prospects of any realistic savings, it really is a complete waste of effort even at the geek level.

I installed air-con with heat-pump heating a couple of years ago, and that looks to provide viable heat. It claims 3.5kW for 1.2kW power consumption. It's very difficult to measure what it produces; it does output more heat than a 2kW fan heater but I haven't got more than 2kW to compare it with so I don't know if it reaches 3.5kW. It is limited to quite a narrow range of outdoor temperatures -- above about 12C and I don't seem to need it, and below about 5C and you can't use a heat pump air exchanger as it will ice up and waste energy defrosting itself. For quickly heating one room it's very good, but as an energy saving measure, it's probably a non-starter. If prices of such units drop to the level they are in some countries where they are more common, then they would be viable for DIY installs.

Take the cost of a kitchen (I think mine was around £4k, but as I did it piecemeal, I never actually added it up) and divide by, say, 15 years life, and that's around £260/year, i.e. it's costing me less than £1/day for a kitchen. That seems like very good value. Of course, if you pay commercial installation rates, it will be a good deal higher. I didn't replace any of the appliances as they were in good shape, replacement was not cost-justified, and they fit in quite well with the new kitchen. I did however plan the new kitchen such that they can be replaced as I don't expect them to all last 15 years.

Reply to
Andrew Gabriel

On 27 Jan 2008 13:29:58 GMT someone who may be snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote this:-

It is a common claim, but still an incorrect one. It may have been true in the 1970s, but that was a long time ago and engineering has moved on since then.

However, unlike a hot water installation, such an installation on a house is unlikely to pay for itself in any financial terms. If someone installs one they should do it for other reasons. In financial terms such installations only make sense if an external supply is not available and they are combined with other sources.

Solar water systems with east and west facing panels work well. Not ideal and more expensive than a single panel (as well as two panels a more expensive controller and perhaps two pumps are necessary), but they still work well.

If one believes the assertions of the antis.

An east/west solar thermal installation which cost say £2000 to install would cost half that, even if it produced no saving of fuel. In reality it would produce a saving in fuel.

Reply to
David Hansen

On Sun, 27 Jan 2008 13:13:49 +0000 someone who may be The Natural Philosopher wrote this:-

To cold for what?

Shunshine is in enough supply in winter to provide some hot water. That reduces the consumption of other fuels.

That rather depends on the relative size of the panel and the window and the angle they face the sun.

Anyway, heat from a panel can be deposited in the north facing rooms via the radiators. Doing the same thing with heat from south facing rooms via fans is possible, but not practised often in the UK. Making suitable ducts in the typical UK house would involve energy, space and money. Modifying an existing heating system is rather less involved.

A common assertion, but still an incorrect one. It may have been correct in the 1970s, but these are not the 1970s. PV panels have moved on a lot since then.

Reply to
David Hansen

On Sun, 27 Jan 2008 13:16:18 +0000 someone who may be The Natural Philosopher wrote this:-

Yawn.

Meanwhile those with an open mind heat nearly all their hot water in summer with the panels you appear to despise so much, produce a significant proportion of it in spring and summer and produce some of it in winter. No doubt you would claim that they are all imagining this hot water.

Reply to
David Hansen

Nobody is disputing that there is *some* heat produced.

The equation is a simple one.

How much heat is produced in the course of (for example) a year from such a panel?

How much would the gas to produce the same amount of heat cost? Project that cost forward assuming an increase in gas prices.

The write down the cost of the boiler over its lifetime and the cost of the solar panel over its lifetime.

That provides the data for the cost of a system using only gas and one using the panel as well and one should be able to calculate the total cost of ownership and use of each. Clearly, there will be some operational cost saving between using gas plus solar vs. gas only. That's the cost argument. One could even do it on an operational cost basis only, ignoring the capital cost.

The other arguments on appearance, feel good and interest in tehnology are valid in themselves.

However, let's have some honesty here and a clear justification of the economic arguments if there are any.

Reply to
Andy Hall

Not much. In spite of much research, their efficiency has only doubled in the ~50 years since they were invented, and almost none of that was recently. Research now is tending to look for alternative materials as no further headway was being made with silicon. There are a few, but a big problem (literally) is that you tend to need a lot of material to make large receptors. Whilst silicon is cheap and in plentyful supply, it's just the processing of it into sufficient purity which is expensive. For anything else that turns out to work well, it's unlikely there will be the volumes of raw materials available in the first place, making them more expensive before you even start with the processing of it into sufficient purity.

It is some sort of step function improvement in efficiency or reduction production cost which is needed to make photovoltaics more viable, but that's just not shown up yet, although there is much research looking for it.

Reply to
Andrew Gabriel

I think you may have missed out something from the list? There is club membership. I suppose it comes partly under the feel good category. Club membership, is equivalent to something like "I feel good, because I'm part of a group who let each other know that they are part of something _different_.". If they can also raise their status in the eyes of others by doing something _different_.

A solar assisted hot water system can easily save it's material, running and maintenance, resource costs - the problem is that in a post industrial economy it can't, at present, save it's installation cost.

Reply to
Ed Sirett

True, the oil companies stop pumping long before that point is reached because of all the other overheads. This means there is quite a lot of reserves which are held back until the price of oil is sustainably high enough. Therefore there will a longish transition period from oil to other sources of energy, which currently are not worth the effort.

Reply to
Ed Sirett

But nor can many items people buy regularly.

Look, today it was very cold but the sun was out. Our boiler became full of water at 31C. What was the average temperature of mains water?

If, say, it was 10C then we saved fuel to heat ours through 20 degrees.

People simply don't understand :-)

Mary

Reply to
Mary Fisher

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.