Does anyone here have an ideological objection to Solar?

Martyn1981

jeepjunkie wrote: »

I wouldn't bother responding... He is very negative about other technologies as well e.g. ASHPs

One thing that really does my goat in is people, not anyone specifically, giving advice about things they have no hands on experience of i.e. don't participate/have a finacial interest in the technology themselves.

That's the downside of the internet, everyone is an expert....

Too true, but .... there is always hope that as technologies and subsidies develop, people will revue their positions. I for one only 2 years ago didn't think PV would have much of a roll in the UK for at least 10 years. But 2 years on I'm shocked at how quickly this has changed.

Also, of course, some people do love to attack anything new, and adopt the lazy expert role of pointing out only the negatives, and skipping the actual and potential positives.

Others then jump on these bandwagons. But normally, over time, we tend to get bored, and realise that we may have over-reacted and things aren't so bad after all, then acceptance slowly matures. Unless of course you've dug yourself such a deep hole that you can't find a way out.

I'll leave the last word to somebody else:

Cardew wrote: »

You no doubt get supportive PMs praising your input - as I indeed got in earlier times - Ah how times have changed!

Mart.

jamesingram

zeupater wrote: »

Hi
A decent specification 6sqm thermal system would likely provide around the same energy gain as somewhere around 18-20sqm of pv ... we get the majority of our annual water heating from a similar sized system and importantly, this is done without any potential timing risk of utilising high-value imported energy.
Regarding space heating, you'll not have anywhere near enough collector area with 6sqm, but you'll also probably not need a heatdump either if the system is properly designed/installed and you have reasonable hot water usage.
HTH
Z

thanks for that Z , what size HW tank do you have to avoid summer over heating ?
cheers James

rogerblack

jamesingram wrote: »

thanks for that Z , what size HW tank do you have to avoid summer over heating ?
cheers James

You shouldn't size it like that.

If you do, then the tank may boil if you're away for a week. My tank hit 90C, which I was quite unworried about, as I was watching it, while the dump radiator was not enabled, however, this was adequate to mean the thermostat on the
electric heater needed reset.
The next day it would have easily boiled.

Turning on the hot tap a little before you go away isn't really a good solution.

There needs to be either a dump radiator, to get rid of the heat, a system which is OK with turning off the pump (vacuum insulated panels are NOT), or some other means of cooling.

Or never, ever go away, of course.

[Deleted User]

grahamc2003 wrote: »

Well in the past I have given lots of advice on Mach 24 scramjets for recoverable air breathing space flight, but I must admit, I've never actuially owned one and, at probably tens of billions each, I'm unlikely ever to.

That is another way of saying this view that 'you have to own something to have an intelligent view on it' is rather strange. If you have a background in the detailed theory of how things work, of course you can have valuable comments on them whether you own them or not.

As regarding 'experts' - well Cardew is a chartered engineer, so I would say he is an expert in engineering issues (and any energy topic is an engineering topic) relative to the general population. I enjoy your posts and Cardews - just because they are different doesn't mean they aren't both valuable.

I'd say one problem with extracting correct information from these boards is the few (not including you btw) 'over enthusiastic amateurs' with no basic theoretical foundation, not experts.

Sometimes I find it a bit disheartening on here especially as I only ever try to see the positives in everything...

I'm chartered too but I'm not saying in what in as I may be ousted from here

Energetic_2

jamesingram wrote: »

thanks for that Z , what size HW tank do you have to avoid summer over heating ?
cheers James

Modern ST systems will stagnate when the tank reaches temp. The pressure keeps the loop from boiling. It does get seriously hot tho...

rogerblack

Energetic wrote: »

Modern ST systems will stagnate when the tank reaches temp. The pressure keeps the loop from boiling. It does get seriously hot tho...

Vacuum solar thermal stagnation temperatures comfortably exceed 100C in full sun.
If the system is designed so it stops the pump, and forms a steam bubble in the collector, this will indeed stop solar input.

Trying to restart the pump will result in a large volume of steam , or dangerously high system pressure.
Otherwise, if the pump keeps running, the solar collector is quite happy to produce heat at a cylinder temperature of 100C.
I initially set my panel up as a test with an uninsulated 40l barrel.
This boiled quite happily.

I question the reliability of ST systems operated with the manifold full of steam at well over 100C. Steam is very corrosive. Unless they are warrantied for this service.
Especially when they have coolant pumped into them causing massive thermal shocks.
http://www.navitron.org.uk/download_images/download_1343722270_241.pdf - gives the output of the panel at 100C delta of 2/3 of nominal.

Martyn1981

jeepjunkie wrote: »

Sometimes I find it a bit disheartening on here especially as I only ever try to see the positives in everything...

I'm chartered too but I'm not saying in what in as I may be ousted from here

Not wishing to teach you to suck eggs, but there is no shortage of detailed info available on PV and general renewables, if you're interested (and bored).

I found it fascinating to read a lot of the large reports describing potential ways forward, and they are all pretty positive. Though on quick revue they've all underestimated the drop in prices during 2012.

Also interesting to see how govt, environmental group and accountancy company reports compare. Very similar in fact.

Also find New Scientist interesting, but generally info on PV is forward looking. Though info on AGW most enlightening (disheartening).

But, by far, the best source of info is on the technical and renewables forums (where the engineers tend to form herds - not sure what the collective term is). Always informative, and happy to explain / discuss / educate. Edit: almost forgot, and the off-griders, they've been there, done it and got the T-shirt.

Last but not least, if you don't mind being a little cheeky, also able to learn loads by simply e-mailing companies and asking. I've found SMA, Stecca, WPD, EDF etc all willing to share info and advice, after all, if you don't ask, you don't get.

Mart.

Cardew

jeepjunkie wrote: »

I wouldn't bother responding... He is very negative about other technologies as well e.g. ASHPs

One thing that really does my goat in is people, not anyone specifically, giving advice about things they have no hands on experience of i.e. don't participate/have a finacial interest in the technology themselves.

That's the downside of the internet, everyone is an expert....

I am not anti the PV technology, but the FIT system of payments - big difference.

With ASHPs I have voiced my concerns in detail - again not about the technology, but the fact that any cowboy can install systems and in far too many cases people spend £10,000+ and buy a disaster with no comeback.

You continually post how wonderful your system is, but there are posters who have ripped them out. Also the 12 month long Energy Saving Trust field trial - with all manufacturers involved - was little short of a disaster.

Their trial was independently monitored and not the highly scientific! 'last year I spent £x and this year only £y.' You, like almost every other ASHP owner(including myself) have no idea of your COP.

Also if you had bothered to read my posts you would know that I have owned an ASHP system in a property abroad since 2003 - albeit Air to Air with ducting. Not to mention research and commissioning a heat pump system for a large swimming pool.

The banal suggestion that you must have hands-on experience in order to comment on its virtues or difficiencies is plain stupid! Have you not heard of 'research'! Prof Stephen Hawking hasn't even experienced space travel; yet people actually believe what he states!

Indeed from your wide experience of a single ASHP system, you felt qualified to comment several times on the difficiencies of the Nibe heat pump - a totally different system to yours.

In any case this is an internet forum - not some cosy self - congratulatory club - and differing views and opinions are allowed!

EricMears

tunnel wrote: »

Thanks, I was led to believe that they had an export meter,as privately owned PV system owners are deemed to export 50% yet in reallity probably export 75%, would have thought it would have been beneficial to the RaR's to have one. Can go and open my gob now

Tunnel

I have of course avoided the RaR merchants like the plague so shouldn't really comment on their 'rules'. However, I'm pretty sure that every property with a solar installation is treated as an individual regardless of how many other properties are registered to send FIT payments to the same company.

Arguably, people (or companies) collecting multiple income streams ought to have them aggregated then paid at the appropriate rate for the total but I doubt that actually happens.

The RaR rooves are therefore no more likely to have their actual exports metered than any others.

Cardew

EricMears wrote: »

I have of course avoided the RaR merchants like the plague so shouldn't really comment on their 'rules'. However, I'm pretty sure that every property with a solar installation is treated as an individual regardless of how many other properties are registered to send FIT payments to the same company.

Arguably, people (or companies) collecting multiple income streams ought to have them aggregated then paid at the appropriate rate for the total but I doubt that actually happens.

The RaR rooves are therefore no more likely to have their actual exports metered than any others.

In the very early posts on the Rent a Roof threads it was confirmed that these companies could claim the full rate FIT for each individual installation.

In fact A Shade Greener(the biggest RAR firm?) confirmed that they had discussed this with the Government and(unbelievably) it had been approved before they set up their scheme.

So initially all ASG's systems were 3.3kWp and they expected to get at least 2,800kWh pa per installation and claimed the(then) 41.3p/kWh FIT. ie at least £1,156 in FIT per installation.

Given, before the FIT reduced, their website claimed to have installed over 10,000 installations; giving an income of over £11 million pa just for the one firm(inflation linked) all paid for by electricity consumers in higher bills.

An absolute disgrace that the Government allowed such a scheme to exist.