Solar - agaian(!)

[Graham Harrison]

Wow, I'm not sure I expected to start quite such a debate!

Can I expand the question a bit?

If I do want to supplement my (oil fired because I'm off the gas mains) radiator central heating and hot water in some way (to try and minimise my oil costs) is there a "better" alternative than Solar?

To say that I can write off the cost of a solar installtion immediately is an exageration. However, I remain employed at the moment, and I'm looking at this as an investment for the future. The thinking is that if I can afford something now that will help reduce my outgoings once I retire it could be a good idea.

I'll ask similar question on the solar group as well but I'm getting a lot of good feedback here so I feel a follow up is justified.

[Doctor Drivel]

Very wise. Look at my post re: insulation.

[Peter Parry]

Almost anything is better than solar water heating - including simply putting the money in a Post Office account! However alternatives require lots of land or a river or access to other materials to use as fuel (and lots of land).

It isn't an investment but a white elephant, the payback period well exceeds the working life of the system so it will never save you money.

Investing several thousand pounds for a return of about GBP25 per year in the future? I have this bridge you might care to buy :-)

Spend the money on improving insulation and stopping draughts. Spend a little more buying more energy efficient appliances as old ones wear out. It is far more effective and will save you much more. Even investing the money in a savings account is more cost effective than solar water heating.

[Doctor Drivel]

He is crystal ball gazing now. In the future, energy prices are going to go one way, and that is up. And that is not looking into a ball.

Others beg to differ.

[--s-p-o-n-i-x--]

IMO, you would do better investing in a decent wood burner.

Often, local wood working businesses will give you all their offcuts for free. All you have to do is collect on a regular basis.

Paypack time is really quick as the fuel is effectively free. It's also ecologically sound as you use wood that'd either end up in a Coucil incinerator or in a landfill somewhere. Wood is a renewable resource also.

sponix

[Pete C]

Bear in mind energy prices are way outstripping inflation and solar heater prices are coming down. So there must be a point at which solar is more economical over a given time frame, energy price and solar heating system cost.

A lot depends on how much the OP is paying to have their water heated and how much hot water they use per day.

A high efficiency air source heat pump such as found on better air conditioners could augment an oil CH nicely and doesn't need any of the above.

Really? These days vacuum tube collectors can be had for £400, if you can DIY fit the system it'll cost a lot less than several thousand pounds. See:

cheers, Pete.

[Jonathan]

It seem, to me anyway, that many arguments against solar hot water are based on figures from the mid-80's, using the most expensive professionally installed system that can be found. I would be interested if Peter Parry could post a quick calculation based on modern systems, and taking into account current fuel prices and trends.

For my part, I'm not going to do the sums for anyone, but the following three websites might be of interest:

final one is a blog from what seems to be a chap building his own eco-house back in 2002. For him, back then, it would have taken 40 years for the system to have paid back BUT somehow his heating was costing him £40 per YEAR(?!) and he lives on his own. So he can still make it pay back even with exceptional circumstances.

Of course, you also need to take into account the grants available, but I've heard these might be fizzling out soon, so look into that sooner rather than later if serious.

[Jonathan]

The link would be nice, huh? DOH!

[Doctor Drivel]

It also creates smoke for the neighbours.

[Peter Parry]

The figures quoted were taken from suppliers prices today. The OP had asked about commercially fitted systems, not DIY ones.

The calculations were done using modern systems and current fuel prices.

[Peter Parry]

Of course it will, but the OP asked about commercially fitted systems.

[Doctor Drivel]

DIYing it is most certainly economically viable.

[meow2222]

Wood makes good sense if you value your labour at zero. But put even a minimum wage price on it and it doesnt make sense any more.

If you could put together a self feeding boiler, and persuade others to dump their wood waste into your woodhole to avoid skip costs, then it might make more sense. Of course I've never seen such a thing.

If you do go wood, get something huge so you dont have to chop or break scrap, it can go in whole. That at least reduces the labour involved.

NT

[meow2222]

yep. Drivel saying it was a wise idea says it all :)

use CFL bulbs, they'll pay back as much as solar DHW.

If you want something more serious, flat plate space heating. For a few hundred in materials, and a very easy ground level no-plumbing diy job, you get 10s of kWhs of heat per day.

or better, repair them

NT

[Jonathan]

Looked at the post again, still can't see where he says that.

[legrandfromage]

I'm not sure I agree with you. I was very keen on installing alternative energy stuff as I renovate my house and got rather excited about all the technologies and grants on offer. I've mislaid my calculations, but I'm sure I worked out that photovoltaics were much worse than solar hot water, and that a wind-turbine was worse too. I'm skeptical about the 4:1 gain ratio of heat pumps, especially with the new space saving mat heat exchangers, and disbelieve anyone who suggests using one with anything other than _low_ temperature under floor heating.

All is not lost however. If you have access to cheap wood and enjoy a real fire, then a wood burner with back boiler is a good idea. If you have to buy your wood (or coal for that matter) forget the back boiler and enjoy the fire on special occasions. Wood pellets are starting to look like a good proposition, but perhaps still a bit pricey as a suppliment to an existing boiler. I'm replacing my ancient Parkray with back boiler with a pellet stove.

LGF

[Doctor Drivel]

As most energy used in a home is for DHW and CH, concentrating on getting this ebergy usage down using high insulation, passive solar and active solar (panels) is well worth it. It is also more cost effective when high insulatiion and passive solar is used.

Of course when appliances are replaced use high efficiency appliances, and that is not AAA rated, they are way above that - some tumble dryers now have heat pumps in them. And low energy light bulbs etc.

[Dave Plowman (News)]

Therefore the cost of any manufactured goods go up with it. Or perhaps you think you can make/transport things without energy?

[Doctor Drivel]

Well spotted, 10/10. Did you get help with that? So best get it done now as the capital cost and fuel will be higher in the future.

[Peter Parry]

"Has anyone here had domestic solar water heating installed? I know this is the DIY group but I'm looking for someone to do it for me."