Solar panels on roof of house

I didn't say that FIT would have a large impact on costs. I still don't think it's appropriate to be subsidising the electricity of the well off from the payments of everyone else. Wind power is an even worse example which is having a appreciable cost on energy and benefits the even more wealthy.

The only reliable renewable energy available to us is tidal barrages but there is no stomach for winning the political argument.
 
I have never considered Solar panels because we have skylights in our roof so don't really have enough roof space left over which is a shame because our roof gets a good 12 - 14 hours of solid direct sun in the summer.

I have considered a wind turbine though.

Here I can buy a full off grid 2kw wind turbine set-up for around the 1500 - 2000 euro mark

It would pay for itself very quickly as we get lots of wind where we are and they are not that big with a full blade diameter of about 5 feet.
 
Just incase anyone is interested, I think Watchdog will be running a small piece on solar pannels being offered by energy companies next episode.
 
JonJ678 said:
PV cells degrade with time. The rate of this is open to debate, I haven't read enough papers on it to be sure. A friend of mine put it at 50% after six years, roughly exponential. She's normally right.
Click to expand...

I just read they are 90% efficient after 10 years? & 80% after 20!
 
JAMAL said:
I just read they are 90% efficient after 10 years? & 80% after 20!
Click to expand...

They are, 50% of 6 years is total rubbish. Unless they've found the worst oldest tech cell they can find.

Any solar cell worth buying comes with two guarantees.

90% after 10years and 80-85% over 25 years.
And that's with safety margins for the guarantee. It's more like 93% over 10 years.
 
JAMAL said:
I just read they are 90% efficient after 10 years? & 80% after 20!
Click to expand...

That's the problem, what they are saying is false, there is no sudden drop off at year 10 it's gradual, most people will have allowed in any financial calculation a 100% efficiency in years 1 - 10 where as there should be at least 1% off every year, it'll compound into a large amount which may make the the figures not stack up.
 
maccapacca said:
That's the problem, what they are saying is false, there is no sudden drop off at year 10 it's gradual, most people will have allowed in any financial calculation a 100% efficiency in years 1 - 10 where as there should be at least 1% off every year, it'll compound into a large amount which may make the the figures not stack up.
Click to expand...

No they really won't.
Unles shout talking about calculation sites. They are estimates only and are flawed just like energy supplier comparison sites.

No manufacture has said it's a sudden drop, u less you can provide evidence.
And any manufacture or supplier who says that (again I need evidence as I simply don't believe anyone is that stupid) would be subject to false advertising.

And it's not at least 1% a year. It a maximum of 10% over 10 years guaranteed.
 
Last edited:
AcidHell2 said:
90% after 10years and 80-85% over 25 years
Click to expand...

Your agreeing with what I'm saying aren't you :confused: people are calculating it as a 100% efficiency for ten years which is wrong, no panel can be over 100% efficient, the only way to overcome that would be to provide bigger panels or more panels that produce more than what they have been sold.

I suppose its a way of phrasing it but the guy I spoke to who's doing ours on site said the graphs that were being used showed flat lines then drops but now they are having to show a proper reflection of true efficiency drops.
 
Who's calculating it like that and who is advertising or selling it like that?

Where are these graphs I haven't seen one single flat graph with sudden drops, as that is not only stupid but leaves manufactures open to legal and civil action.
 
It's an estimate, you don't even select what solar panel manufacture you got, so it is a crude estimate. What do you expect. Calculators don't even now what efficiency your panels are to start with currently around 9-13%, this is why they are estimates.
 
maccapacca said:
Something that's not misleading?
Click to expand...

No because the manufactures and suppliers have the exact details. This calculators all quite clearly say estimates and say it depends on variables.
However they should be in the right ball park, unless you bumpy some panels for £100.
 
maccapacca said:
Something that's not misleading?
Click to expand...

The site I used for working out savings/payback assumes only 85% efficiency of the panels over their life.

In reality, to begin with you will get more.

Also, it's only an estimate as who is to say we will have as much sunshine in 20 years time as we do today (or vica versa)

Whether it's 6,7 or 8 years to get your money back, with the FIT at current rates, you can make a very, very good return on your investment which is better than anything else I can find.
 
JonJ678 said:
I shall have to persuade my friend to part with the source for her 50% / 6 years figure. Thanks for your perspective Castiel, much appreciated.
Click to expand...

The source for this is not forthcoming, at least not in the near future. Please assume I was just wrong :)
 
just had a quote from a solar guy.

We have 2 houses that need them, ours and mother in laws.

Been quoted £22000 for the 2 3.83kw systems. Could generate about £3500-4000 a year in total as both are south facing. We would pay for them on both houses and get the generation tariff and the mother in law can benefit from cheaper bills.

Seems a great investment.
 
Make sure the roof doesn't need any work before installing panels, even iffy tiles need replacing, huge ball ache if the roof starts leaking once the panels are on.
 
Spit said:
Been quoted £22000 for the 2 3.83kw systems
Click to expand...

I've just placed an order for 36 houses providing 30 KWp in total for £99,000 =£3,300 per KWp yours is £2,872.06 per KWp so that's very good value

I assume that's lay on roof system, we buy lay in roof systems that are 10-20% more expensive
 
You must log in or register to reply here.
Back
Top Bottom