Hi Jeff
We fit these systems, we have about 40 systems running in the UK. with customer very happy with the results system cost about 8k, fitted 13K
But we need large roofing space minimum of 15Sqm.Plus if you got a swimming pool we can incorporate this as well with the same system.
Many thanks jeff.
Paul

<blockquote><cite>Posted By: Jeff B</cite>Ample - unfortunately that is well beyond my budget. I didn't realise you were an installer of solar heating systems; I thought you were a DIY-er who had built his own system and had a few tips to share! Thanks anyway.

Jeff B.</blockquote>jeff we are DIYer but specialists in solar

I tend to agree with rumi in the previous post.

The ideal might be to give the customer a balanced picture of the hugely various concepts which pass for efficiency such as this marathon which ranges from component to global in its approach:

Collector stagnation temperature
N(o) (absorber) on its efficiency formula (which is what excites vaccy tube people)
N(o) (aperture) on its efficiency formula (which, being lower, has less sex in it)
to and from pipe dead leg volume
heat storage design and size / panel area
annual panel delivery
annual system delivery
annual fuel saved
annual energy saved
annual carbon saved
annual solar fraction of each bit
duration of any warranties for each bit
the labour warranty
key warranty exclusions
life expectancy
reliability
accreditation
maintenance frequency and costs
embodied carbon
operating energy parasitics
operating carbon clawback percentage
whole of life carbon and energy budgets
capital cost £
operating and maintenance cost £
whole of life cost £
and so on!

Then to name which collectors or systems tend to be best at each one.

The to ask the consumer to prioritise this list.

Then to congratulate the customer on their choice, whatever it is, provided that it is not to abandon solar at all.

In the less than ideal world, we spend more time explaining explain the benefits of our technology, as most solar hot water suppliers do. You can probably guess what would be are given that I run a solar innovation business!

Regards, Barry

Hi, has anyone got any experience of these? http://oxfordrenewables.co.uk/solarfocus-cpc
Planning to DIY something similar as it seems a nice way of concentrating the sun in a low profile package.
They call it CPC (Compound Parabolic Reflector), but it looks more semi-circle to me. I came to the conclusion that a semi-circle (or maybe a third...) would give good collection without tracking as long as the pipe had a fin to pick up on the plane focus.

...Mark,

Killing threads off seems a bit harsh, you will recall the thread wad started on the basis of what are the pros and cons...

ie which horses for which courses...?

J

(100 yeah! )

anyone care to answer brig001 above, I like this design and would like to hear from anyone with an opinion or hard facts on this product.

Hi joe90, still no info on that actual product, but I have managed to DIY one. Unfortunately, I found out that the panel is the only one part, the plumbing etc takes time too, consequently, I have run out of time this year. I have put a pre-heat tank in the loft, all connected to the DHW circuit, so I "just" need to mount the panel and connect it all up. When I get some figures, I'll post them here.

Bri.

When it comes to vacuum tube systems, naturally some are better designed than others. The LaZer2 from SolarUK.com is one of those which has done away with the glass to metal seal on the collectors (which have the potential to fail). It comes with a 25 year warranty. The great thing about renewable products like this is that you are effectively buying 25 years of energy in one go. With gas and electricity prices set for further hikes, as a result of the unstable global market highlighted in the recent Ofgem report into the UK's energy supplies, a solar hot water system is looking increasingly cost effective.

My main concern over ET systems was the failure of the vacuum (I have had a lot of double glazed panels fail recently) but with a 25year guarentee on the tubes I will look long and hard at the SolarUK system.

All the cheapo chinese 47mm and 58mm tube panels have done away with the glass/metal seal too. So no advantage there (only the 70mm tubes have the metal/glass seal).

Solarfriend - you say you see no advantage in ET systems, and describe them as 'complicated'. There is no complexity difference between ET and FP setups. Both can be very simple. And I still haven't seen anyone selling FP panels in the UK that are cheaper than than the eco-nomical ET panels. So SFAICT looks are the only reason to choose FP. And limited roof space is the only reason to choose any of the expensive non-chinese ETs.

Hmm, may be a bit strong to kill the debate MarkK, but I do understand how you feel. The GBF (F appears to stand for Fantasy to me sometimes!) is a microcosm, but reflects the larger world outside - and not everybody - especially the experts (vested interest?) - agree there either. Some common sense is being injected in these latter comments, which is welcome in a confusing and often technical debate.

Some interesting points are being made for and against on both sides. Excepting perhaps Thermomax, who I understand (not first-hand, but from a colleague who has fitted much of their gear) have had their own issues, the ET tube market is not by any means mature. Nor stable, or profitable, when big players like Schott and Vaillant drop off their perch. Nor as reliable as I would wish were I asked to make the investment. It is developing. As is FP technology, albeit more slowly. But when a FP system like Filsol - a very simple, modular (read 'easily replaceable') stainless steel sheet collector, can have a proven life of 30 years + AND perform better (DTI report) than not one, but several ET systems, we are into what appears to me to be a rather misdirected debate.

I have fitted alternative energy systems since 1978, starting with WB stoves and diversifying into varying shades of green since. And solar is a definite part of that mix. So I am an installer - and I integrate technologies. Hence my perspective is different from a customer, a solar provider, or even a designer, any or all of whom are entitled to diagree with me...and who may be right.

My tuppence worth: If I have learned two things which may be relevant in this debate, they would be these:

Firstly: In this debate, and hence your purchase decision, try and ignore lengthy warranties, even underwritten ones. They confuse the issue and cause us to suspend critical judgement with the presumption that the product must be good when it has a bigger warranty. Witness the automotive industry - cheaper-built cars with hugely better warranties than demonstrably better ones.

A good name for quality, longevity and back-up is worth a lot more to me than a prolonged warranty. Why? Well, we saw this in the '80s when, due to unexpected problems with stainless applications, a lot of WB chimney systems fell apart. One, a reputable firm with a great product for the time, had a 25 year warranty - I still have the paperwork - but with the problems, the firm had folded more quickly than the paper its warranties were printed on. 'Underwritten' I hear you cry....? No. The ongoing financial crisis - predicted and fulfilled by Drs Leeb et al - has shown that there is a worldwide financial instability which can leave very little untouched. When sacrosanct fiscal depositories like pension funds in big PLCs can be raided, what hope guarantee depositories in faceless backstreet insurers.

Secondly: I fit what the customer is comfortable with, bearing in mind all the caveats in previous posts. I would advise people to get past the FP vs ET vs whatever-unproven-technology-may-come-along debate and focus instead on HOW we are using what we already have. We are straining down the gnat but gulping down the camel when we are not even using what we have to its full potential. Anybody who fits a system - FP or ET - which is designed to stagnate is fitting a system which is not even half green.

Why? Because it is wasting potential energy. Energy which could be reducing our gas/oil/even log consumption. According to the Met Office, (and ignoring 2008!) we usually get get 30-40 days where solar will work well in the shoulder seasons down here. We have had an exceptional late summer and autumn (I 'hail' from Cornwall btw) which has already exceeded that quota, and the systems I have fitted over the past few years - ET or FP - which are storing that 'excess' solar energy instead of allowing it to fritter away in stagnation - have been able to dump that heat in the cool evenings into the house for space heating - UFH or rads.

Do your own figures, work out your own payback, but if your two panels have heated the DHW and can be re-directed to pre-heat the CH in a Thermal Battery (my term, as it re-charges slowly, but call it what you like, Thermal Store is often used), you will be cutting years off your payback (I feel another debate coming on....)
Now think what five or six panels could do to your ongoing fuel bills - and yes, your property value, as, like it or not, homes which are cheap to run and comfortably warm are going to rise fast in value against bigger, colder mausoleums.

A few people on this forum have already done this - Johan I remember for one. So I submit my point and shall call it the Stirling Moss Principle - it is less important what you drive than how you drive it.

Regards from Sunny Cornwall!!

Crusoe

crusoe,

Thanks for a balanced, sensible, contribution.

(P.S. missed you)

not possible

Wasn't sure I was allowed to post links to suppliers here. It might sound like I'm promoting them! Anyway, here you go:

http://www.solexenergy.co.uk/ (they don't have the panels on their website, but I know they are shifting their old stock atm so there is true bargins to be had. Good location for you crusoe I think, no?)

http://www.earthwindfire.co.uk/ (I don't know their current pricing, but these are the ones I have and I paid a fair bit less then the ET's cost)

I have no connections to either of them, and I don't think there is anything wrong with ET's! You need to consider all parameters when you choose the panels for your system.

If you are going for these tubes be careful to select the right ones. there are two types.

Tubes which are connected (bonded) as a single unit to the copper fluid outlet. This eventually cracks due to constant expansion and contraction, the vacuum is lost and the efficeincy of the tube plummets.

Better to consider the all glass tube that fits around the copper collector, there is effectively nothing to go wrong and this type of tube can be guaranteed for many many years. An example can be seen on the www.solaruk.com website (Amber mentioned this above) though I am sure many other suppliers also use it.

With regard to price, on my own website I have managed to work up a bit of a price comparison, this is now about a year out of date but I'm sure still relevant. It shows 4 of the main suppliers, all about £4,000 for typical installation.

http://www.solarkent.co.uk/solar-water-heating/comparison.asp

I'm sure the introduction of the Renewable Heat Incentive is going to change all the costs etc. Don't ask why and how, its just that free money always does.