Just look at the overhang!

[SolarRoofSols]

For the record - we did NOT install this!! South West facing, sandwiched between 2 x 2 storey houses and just look at the overhang on the top l/h corner.

Would love to see how their generation figures are measuring up to what they were quoted!

 

[D Skelton]

There's a house down the road from me that has the entire north facing side of the roof covered, to add insult to injury it's shaded from the entire east side by a 50ft oak tree!

This house is the very reason I decided early on that I wouldn't be involving myself in the whole solar scam. A complete waste of money, time and effort to install a solar panel in the UK. A joke to then install them badly

 

[SpitfireW'sale]

Because some people do things badly it doesn't mean that thing is not worth doing. Interesting profile picture by the way.

 

[D Skelton]

I think my point was that it's not worth doing it anyway. Doing it badly then just makes it laughable. Solar panels are what, about 30% efficient on average? Then deduct a further 80% from that initial 30% for a solar panel in the UK and what you're left with is a rather expensive mess on your roof, an invitation to thieves and a danger in high winds. All this for an astronomical sum of money that won't be recuperated for at least 25 years. I'd say anyone buying a solar PV system is either completely bonkers or has been missold the product!

I don't blame the installers for fitting them (well, that is), they are just supplying a service for which there is still a tiny amount of demand for. Neither do I blame the fitters for installing completely useless North facing systems when the FIT rates were still at criminally high levels. I do blame the government however for allowing this misrepresentation of solar power to go on for this long.

 

[JulianC]

Never let the facts stand in the way of a good moan!

 

[D Skelton]

As near as makes no difference they are facts mate. Solar PV in the UK is about as useful as an ashtray on a motorbike! Solar thermal is the only system I would ever consider fitting to my own house (provided the figures worked out[initial outlay costs, money saved per annum, timeframe of recuperatio etc.. ]).

 

[JulianC]

As near as makes no difference they are facts mate.

But they're not though are they? They're just your misguided understanding of the facts. How are they 30% efficient and why are we deducting 80% of that and how is that of any relevance anyway (I'm assuming you don't pay for sunlight)? Expensive mess on your roof? That's an opinion, not a fact. Invitation to thieves? Good luck to them - if they can get up there, remove the panels and then sell them on they probably deserve it. By that rationale, I'd better not park a car on my drive. Money that won't be recuped for at least 25 years? Again, wrong.

I can understand people not liking them but at least get the facts right before making an informed decision.

 

[D Skelton]

They are about 30% efficient at extracting energy from it's source, there are other types of renewable energy that are 90% efficient at extracting that energy. That is a fact my friend, or at least it is until tecnological advances mean that solar power is more efficient than it is currently. So given that a solar panel can extract 30% of the suns energy, a figure that is calculated when the panel is exposed to as much sunlight as it can gather, for example facing up in Ethiopia, in the UK however they perform at roughly 80% of what they would on the equator. Again, I say that these are facts, not made up gumpf.

 

[JulianC]

They are about 30% efficient at extracting energy from it's source, there are other types of renewable energy that are 90% efficient at extracting that energy. That is a fact my friend, or at least it is until tecnological advances mean that solar power is more efficient than it is currently. So given that a solar panel can extract 30% of the suns energy, a figure that is calculated when the panel is exposed to as much sunlight as it can gather, for example facing up in Ethiopia, in the UK however they perform at roughly 80% of what they would on the equator. Again, I say that these are facts, not made up gumpf.

Whether it's a fact or not (and it sounds like tenuous pseudo-science to me, comparing apples with oranges), it's of absolutely no relevance to justifying whether or not it is worth sticking solar panels on your roof here in the UK.

 

[telectrix]

i think that whoever invents a device that can generate electricity from rain will be on a winner. what is this "sun" you talk about? :13:

 

[SibertSolar]

They are about 30% efficient at extracting energy from it's source, there are other types of renewable energy that are 90% efficient at extracting that energy. That is a fact my friend, or at least it is until tecnological advances mean that solar power is more efficient than it is currently. So given that a solar panel can extract 30% of the suns energy, a figure that is calculated when the panel is exposed to as much sunlight as it can gather, for example facing up in Ethiopia, in the UK however they perform at roughly 80% of what they would on the equator. Again, I say that these are facts, not made up gumpf.

Pardon?? Can you elaborate on these "facts" please, for the benefit of those who don't have any understanding of what you are talking about?

 

[saint]

There's a house down the road from me that has the entire north facing side of the roof covered, to add insult to injury it's shaded from the entire east side by a 50ft oak tree!

This house is the very reason I decided early on that I wouldn't be involving myself in the whole solar scam. A complete waste of money, time and effort to install a solar panel in the UK. A joke to then install them badly

It is clear to all of us who read and post regularly that you are not informed enough to comment accurately. I suggest you get some knowledge on the subject and come back to us with and informed opinion. I'm pretty sure it will be different to the opinion you have now.

 

[D Skelton]

Pardon?? Can you elaborate on these "facts" please, for the benefit of those who don't have any understanding of what you are talking about?

Here you go:

World Record Solar Cell with 44.7% Efficiency ? Fraunhofer ISE

WORLD RECORD at 44% efficiency. I said they are "about 30% efficient", which your average solar panel is. That means it's efficiency at converting the sunlight into energy as a product.

On top of this is what the solar panel is rated at under standard test conditions which is a flash test in the factory that has been calibrated to deliver the equivalent of 1000W/sqm of sunlight intensity, well here in the UK at the very most we can expect to get 75% of this on the very hottest of days as we are not in the most direct path of sunlight. Well how many of these scorching days can we expect to receive here? maybe 8 weeks per yer, average day being overcast for at least a partial day? On average we can expect a solar panel in this country to produce 20-30% of what it is rated for under STC.

Enough elaboration for you?

It is clear to all of us who read and post regularly that you are not informed enough to comment accurately. I suggest you get some knowledge on the subject and come back to us with and informed opinion. I'm pretty sure it will be different to the opinion you have now.

Read above reply.

If we can only expect on average 20-30% of what STCs tell us a panel can generate on a south facing roof, what hope in hell have solar panels on a shaded north facing roof got of producing any power at all?!

Now I throw your rather petty accusation back at you!

My only point was that solar power is crap compared to other renewable energy sources, ESPECIALLY when it has been installed badly.

Read what I said again and stop the petty dramas. I haven't called anyones integrity into question so would you all please stop acting as if I have!

 

[JulianC]

Seriously fella, time to stop digging :rofl:

 

[D Skelton]

Seriously fella, time to stop digging :rofl:

Seriously fella, time to start explaining why I should stop 'digging'!

 

[Darkwood]

I was so apprehensive of opening this thread ... going by the title i thought it was going to be a pic of you tea bagging and bragging ..PHEW!!!!...

 

[JulianC]

Seriously fella, time to start explaining why I should stop 'digging'!

I think Saint pretty much summed it up with his post. Your arguments as to the unviability of PV in the UK are neither relevant nor accurate.

 

[D Skelton]

Listen mate, don't just sit there comfortably tapping away telling me I'm wrong, explain how! People have asked for elaboration and I have elaborated, I have provided the knowledge I have on solar panels as well as data from manufacturers. At least afford me the same courtesy! I'll concede that my points are irrelevent to the content of the OP as I have digressed somewhat from the main topic, but my points are accurate none the less.

If I'm wrong then provide some sort of evidece that supports that claim and I'll listen, until then, I will continue to think that people who blindly sing the praises of a power source that has been proven to be highly innefficient are slightly mad!

If you are going to make money from installing it then why not, if you or the customer are going to get a good deal out of doing so then even better! but don't sit there telling me that solar power is the best thing since sliced bread because that would simply be a lie!

 

[JulianC]

It's no great secret and the information is freely available. See here for starters: Solar electricity PV (photovoltaic) panels explained - benefits, costs, savings, earnings, suitability

Don't confuse your ignorance of the subject as evidence that it's a waste of time (I don't wish that to sound rude so please don't take offence). Cell level efficiencies are irrelevant in so far as you are not paying for sunlight, therefore the amount of light a panel converts to electricity is not relevant (available roof space notwithstanding).

My 3.7kW is not ideally sited (split over a south and west roof at 50 degrees), shaded at times, will generate around 3000kWh per annum and will pay for itself in around 7 years. That's a fact, not information copied and pasted from the internet.

 

[D Skelton]

My 3.7kW is not ideally sited (split over a south and south-west roof at 50 degrees), shaded at times, will generate around 3000kWh per annum and will pay for itself in around 7 years. That's a fact, not information copied and pasted from the internet.

Fact from where? I have a friend with a 3kW system (all south east facing) and his produces roughly a third of that?! Explain that?

 

[jason121]

Fact from where? I have a friend with a 3kW system (all south east facing) and his produces roughly a third of that?! Explain that?

Installed between two houses that's why

 

[D Skelton]

Installed between two houses that's why

Nope, completely unshaded. Decent panels, correct inverter for the system, good installation, reputable installer.

 

[JulianC]

Nope, completely unshaded. Decent panels, correct inverter for the system, good installation, reputable installer.

Well either one of more of those things is untrue or there's a fault. Unfortunately my blind, remote diagnostics don't extend much beyond that so your mate would probably be better served by getting someone in to have a look.

 

[ExtremePV]

D Skelton...
Please return to your flat earth where global warming doesn't exist.

I welcome sensible debate but fail to understand why someone who is obviously so ill informed, skim reads google results and obviously has no interest in solar is posting here?

Your 'facts' are wrong...period. PV panels aren't 30% efficient...they are 15-20% efficient, but ********...you look at the headline % figure to base your opinion on.
Solar does work, is financially viable and is an important but often overlooked part of our future energy supply. These stupid comments are damaging, as there are too many other lazy, armchair experts out there who start quoting this crap as fact.

I take it you don't drive a car? They are obviously equally useless due to there 30% efficiency.

I'm posting this as I feel it is important that information posted online is factual. Anybody reading this thread in the future...please ignore ******* comments and do your own proper research.

Ken

 

[tidyboiler]

I think they look as ugly as those windmills that don't even turn, and blight our green and pleasant land. :boxing_smiley:

 

[Gary K]

Fact from where? I have a friend with a 3kW system (all south east facing) and his produces roughly a third of that?! Explain that?

I would suggest he gets an "expert" in to look at the system.

If you look at the link in my signature, you can see what a half decent system generates

 

[onions1066]

There only one way to sort this out...............................................fight

 

[D Skelton]

D Skelton...
Please return to your flat earth where global warming doesn't exist.

This has got nothing to do with global warming?! It has to do with solar panels. If you must know however then my view, based upon plenty of fact, is that we humans are not responsible for climate change, our impact on the planet is a drop in the ocean compared to the chemicals the planet pumps in to the atmosphere itself! Our money should be spent on what to do when the ice caps do melt, rather than some sort of useless attempt to prevent it from happening! Not that it's relevant to the debate, although I probably have 'pot' and 'kettle' syndrome by saying that after what I have done to the thread.

I welcome sensible debate but fail to understand why someone who is obviously so ill informed, skim reads google results and obviously has no interest in solar is posting here?

Yes, I'm sorry, you're right, all I did was skim read google! I have no experience of reading the masses of complaints out there from people who are confused as to why their PV system isn't performing as they were told it would!

Your 'facts' are wrong...period. PV panels aren't 30% efficient...they are 15-20% efficient, but like every expert idiot...you look at the headline % figure to base your opinion on.

Haha, brilliant, so they are even worse that I thought! You prove my own point!

Solar does work, is financially viable and is an important but often overlooked part of our future energy supply. These stupid comments are damaging, as there are too many other lazy, armchair experts out there who start quoting this crap as fact.

If we're going down this road then no, they don't work, not as a viable alternative to energy production! They help, a little, but that's it! Future energy supply will be nuclear, end of, and any money invested in renewable energy should go into hydrogen research, thats my two cents anyway

I take it you don't drive a car? They are obviously equally useless due to there 30% efficiency.

yeah, cars are crap as they are, when they are all fuelled with hydrogen then they will be better, your point is?

I'm posting this as I feel it is important that information posted online is factual. Anybody reading this thread in the future...please ignore******* comments and do your own proper research.

All you do is devalue any credibility you could have by using disparaging language political dogma as ammunition instead of factual and intellectual debate. More fool you.

 

[JulianC]

This post is nothing to do with proving whether or not pv is worth fitting and everything to do with who's ego is massaged the most in having the last word. This is my go. I fear I shall not win...

 

[D Skelton]

This post is nothing to do with proving whether or not pv is worth fitting

It was, up until everyone started chirping up with "You're an idiot", "You don't have a clue what you're on about" and "Your facts are wrong", without anyone actually showing me otherwise!

I understand I may have rocked the boat a little by speaking out on the solar section about the fact that PV isn't all it's cracked up to be, but treating me with the same contempt as you would someone who has murdered a member of your family just seems odd to me! lol

 

[MDJ]

It was, up until everyone started chirping up with "You're an idiot", "You don't have a clue what you're on about" and "Your facts are wrong", without anyone actually showing me otherwise!

I understand I may have rocked the boat a little by speaking out on the solar section about the fact that PV isn't all it's cracked up to be, but treating me with the same contempt as you would someone who has murdered a member of your family just seems odd to me! lol

It's your own fault for having a picture of Geordie spark as your avatar lol

 

[SibertSolar]

I get it, this is the Friday evening general electrician's forum "let's wind up the PV boys" thread.....lol.....nice one, very good, have 10 internetz

 

[ExtremePV]

Calling you an idiot for what you've posted on a public forum doesn't devalue any of my credibility - I'm 100% accurate and simply stating a fact that everyone here can see. My language has been quite restrained considering the crap you have been spouting.

Are you on here because your friends system doesn't work or what? If its under performing get someone to go and fix it.

I think I get this now.... your going to announce any second now your either an Architect or the new energy minister.

 

[D Skelton]

Calling you an idiot for what you've posted on a public forum doesn't devalue any of my credibility - I'm 100% accurate and simply stating a fact that everyone here can see.

Speak for yourself why don't you haha.

I'm 100% accurate

Of course you are pal

My language has been quite restrained considering the crap you have been spouting.

Crap? Well that is subject to opinion. You have stated yours, I have stated mine, can't really say much else other than mine is just as valuable as yours, or at least it was until you started being abusive, then whatever opinion you had went out the window!

Are you on here because your friends system doesn't work or what? If its under performing get someone to go and fix it.

I think I get this now.... your going to announce any second now your either an Architect or the new energy minister.

Nope, just a level headed guy who isn't taken in by whatever looney climate change policy is dreamt up as a knee jerk reaction to spurious evidence at best.

I've said all I have to say to you, welcome to my block list. No matter how much others disagree with me, not a single one decided that it would be appropriate to be abusive. That is the difference between someone who gets listened to regardless of their opinion and someone who doesn't.

Ta da

 

[ExtremePV]

Sorry if you think this is abusive then you really have lived a sheltered life.

I'm glad you've said all you have to say, and your Google link building.

My final word on this.. Solar is the 2nd largest source of new energy this year in the USA (I read largest in one report)
So if as you say solar doesn't work, why has Germany installed huge amounts and USA + Japan + China now following suit?

https://www.greentechmedia.com/arti...rmany-in-Solar-in-2013-930-MW-Installed-in-Q3

Solar energy is cheaper than diesel now, which is why one of my customers is £450k a year better off...for the next 20yrs. They know it works.

If you ACTUALLY look at the evidence, and look at it with an open mind you will see it does work. Yes there is still plenty of room for improvement, but its working and viable now.

 

[Gavin A]

D Skelton... to pick up on a few points.

Solar PV is nothing like 30% efficient
No solar PV panels currently on the market get anything close to 30% efficiency, most are in the region of 15-16% efficient, with the highest being something like 21%. Take off another 10-20% losses from the inverter, cables, temperature reductions, angular reflectance etc.

So if you're going to attempt to slate solar PV on this basis you'd come across at least slightly more like you knew what you were talking about if you used figures in the region of 12-18% overall system efficiency, 30% is the stuff of PV installers wet dreams.

Solar PV is infinitely more efficient than the previous roof covering.
Tiles, slates, sheet metal etc are all utterly useless at converting sunlight to electricity, compared to them solar PV is infinitely more efficient at that process. We now have 3GWp of solar PV generation capacity in the UK, instead of the zero generation capacity we'd have had in those locations if the solar PV hadn't been installed.

This point applies to most renewables other than thermal generation (ie biomass, biogas etc)

Grid connection capacity is the main limitation for solar PV not efficiency
For most customers, and the country in general, the main limiting factor for solar PV generation is the capacity of the local grid network / transformers to handle anything like the level of generation that's actually possible from the roofs of the houses / other buildings that are connected to each transformer.

Many houses are now capable of generating 50%-100% of their annual electricity consumption level
The average consumption level for UK households is around 4,500kWh a year, the average annual generation figure for a 4kWp solar PV system is in the region of 3600kWh per year, or 4500kWh per year for a 5kWp system (the biggest standard system we install on a standard 16 amp G83 connection limit).

Granted, much of this electricity tends to get exported, but it's ludicrous to attempt to argue that this level of generation is in anyway negligible.

Solar PV costs have fallen by 50-60% in the last 3-4 years, gas generation costs have increased by 50-60% in the same time period.

Solar PV vs Nuclear
Solar PV capacity is being installed at a faster rate than nuclear, with solar PV capacity on course to be generating significantly more per year by the time the first new nuclear plant opens than that plant will, with new solar PV capacity at that time generating at a significantly lower lifetime cost per kWh than the price nuclear has been guaranteed.

Nuclear is also the only energy generation technology to have had a massive increase in the level of support being offered under this government, with the nuclear clean up costs alone now accounting for over half of DECC's entire budget, and the costs just keep rising.


There's a few pointers to get you started.

 

[Marvo]

Financial outlay and payback time with previous FIT's.
Financial outlay and payback time with present day and future FIT's.
Efficiency in relation to their carbon footprint.
Actual performance compared to advertised performance.
Aesthetics.
Viability and cost effectiveness when compared to other renewables ie 'bang for your buck'.

These are all the issues that have already cropped up but it seems to me you're all lumping too many facets of PV ownership together to have any kind of meaningful discussion especially when some of them are simply personal opinion and some may be a much larger consideration on particular installations than others.

 

[Gavin A]

Financial outlay and payback time with previous FIT's.
Financial outlay and payback time with present day and future FIT's.

financial outlay is around 50-60% lower now than with previous FITs, payback times are roughly similar for domestic, and significantly lower now for commercial installs with high daytime energy consumption than they were in 2011.

Efficiency in relation to their carbon footprint.

In the region of 3-5 years for most systems in the UK, maybe a bit longer for small systems with relatively higher per Wp embeded carbon, or those where the install team has travelled the length of the country etc.

Well installed, quality solar PV systems should have a design life of at least 40-50 years, probably longer, allowing for a replacement inverter every 20-30 years or so, and a gradual reduction in efficiency of the panels (panels installed in the 70s have been measured with only around a 10% reduction in efficiency vs their original rated output).

Actual performance compared to advertised performance.

98% of solar PV systems in a 2 year study by sheffield university researchers are performing at or above their predictions. (link)

Aesthetics.

Aesthetics are important, and there are some terrible looking installs out there which has given the industry a bit of a bad reputation, and often makes me cringe when I see some of them. We've always paid attention to this issue, and now almost exclusively install all black panels, and try to encourage roof integrated panels if possible for situations where the aesthetics are most important.

Viability and cost effectiveness when compared to other renewables ie 'bang for your buck'.

for the majority of people solar PV would beat all other renewables hands down IME with or without subsidies. In some situations this won't apply, eg if they have very good wind resources, or very poor roofs for solar, but it would hold true for most.

These are all the issues that have already cropped up but it seems to me you're all lumping too many facets of PV ownership together to have any kind of meaningful discussion especially when some of them are simply personal opinion and some may be a much larger consideration on particular installations than others.

There's a difference between personal and professional opinion.

 

[whinmoor]

The big clincher for me and most of our customers is the fact that it makes them partially "energy independent". It protects them, to some degree at least, from rising energy prices and gets them out of the clutches of the Big Six. Individuals can't own their own nuclear power stations and in most cases wind turbines and hydro options are also non-starters. But, every building in the country has a roof and a large percentage, both residential and commercial, are suitable for solar panels.

It is also educational in that people become increasingly aware of how much energy they are consuming. We fitted an energy monitoring device today for a customer and demonstrated how much it shot up when they switched on their kettle. They then "clicked" to the notion of only filling the kettle halfway when they make a cuppa.

 

[D Skelton]

D Skelton... to pick up on a few points.

Solar PV is nothing like 30% efficient
No solar PV panels currently on the market get anything close to 30% efficiency, most are in the region of 15-16% efficient, with the highest being something like 21%. Take off another 10-20% losses from the inverter, cables, temperature reductions, angular reflectance etc.

So if you're going to attempt to slate solar PV on this basis you'd come across at least slightly more like you knew what you were talking about if you used figures in the region of 12-18% overall system efficiency, 30% is the stuff of PV installers wet dreams.

I was using the figure of 'around 30%' because of a New Scientist article I was reading last week about the 'next generation' of solar panel. The fact is that in a few years it will be 40% and in many years to come potentially more. The exact value, whether 20% or 30% is not really the point, the point is that the value is low!

Solar PV is infinitely more efficient than the previous roof covering.

Tiles, slates, sheet metal etc are all utterly useless at converting sunlight to electricity, compared to them solar PV is infinitely more efficient at that process. We now have 3GWp of solar PV generation capacity in the UK, instead of the zero generation capacity we'd have had in those locations if the solar PV hadn't been installed.

This point applies to most renewables other than thermal generation (ie biomass, biogas etc)

I can't disagree with that. PV is better than nothing for sure, but for the cost??? I'd sooner spend the money on LED lighting, correct insulation and A rated windows and still have enough money left over to go for a beer, or a thousand, after fitting it all

Many houses are now capable of generating 50%-100% of their annual electricity consumption level

The average consumption level for UK households is around 4,500kWh a year, the average annual generation figure for a 4kWp solar PV system is in the region of 3600kWh per year, or 4500kWh per year for a 5kWp system (the biggest standard system we install on a standard 16 amp G83 connection limit).

Granted, much of this electricity tends to get exported, but it's ludicrous to attempt to argue that this level of generation is in anyway negligible.

From what I have seen and heard, I find these figures hard to believe, especially when the average light energy intensity in the UK on a south-facing roof is around 250 Watts per square metre (I can cite many sources for this figure). How is it possible for a 4kW system to produce 3600kWh per year???

Solar PV costs have fallen by 50-60% in the last 3-4 years, gas generation costs have increased by 50-60% in the same time period.

Yes, they have, reliance on fossil fuels is ridiculous, I agree.

Solar PV vs Nuclear

Solar PV capacity is being installed at a faster rate than nuclear, with solar PV capacity on course to be generating significantly more per year by the time the first new nuclear plant opens than that plant will, with new solar PV capacity at that time generating at a significantly lower lifetime cost per kWh than the price nuclear has been guaranteed.

Nuclear is also the only energy generation technology to have had a massive increase in the level of support being offered under this government, with the nuclear clean up costs alone now accounting for over half of DECC's entire budget, and the costs just keep rising.

According to the government’s own figures, nuclear power is the cleanest of all the methods of power generation, taking everything into account from mining uranium to decommissioning and waste disposal. It emits half the CO2 from wind power, 100 times less than gas and 200 times less than coal. In large amounts of studies that have taken place, nuclear energy is the cheapest method of generating electricity taking everything into account. The other thing that no one seems to think of is that we will never run out of uranium! And contrary to popular belief, nuclear waste is nowhere near as polluting or as dangerous as people make out. It constitutes no more than 0.1% of all the UK's hazardous waste production and with the new generation of nuclear power stations creating 90% less nuclear waste than current ones, this figure of 0.1% stands to fall even more!

 

[SPARTYKUS]

I know a farmer that got a nice range rover off the back of agreeing to bury something in a concrete bunker for....ever 20 metres down in a field. And never grow crops on it. He's happy arty:arty:

 

[legoman]

I can't disagree with that. PV is better than nothing for sure, but for the cost??? I'd sooner spend the money on LED lighting, correct insulation and A rated windows and still have enough money left over to go for a beer, or a thousand, after fitting it all



From what I have seen and heard, I find these figures hard to believe, especially when the average light energy intensity in the UK on a south-facing roof is around 250 Watts per square metre (I can cite many sources for this figure). How is it possible for a 4kW system to produce 3600kWh per year???

I have done all the things you have suggested, LED's, loft insulation and "A" rated windows.
(used my FITs payment to do them)
I also have a 4kW South west facing SP system. My usage has dropped from over 5000kWh a year (in 2011) to 2450kWh last year. Most of the savings come from my SP

This year from Jan 1st to now, I have generated 3560kWh and should be close to 3600kWh by year end.
Anyone with a 4kW, South facing system, with no shading should hit 4000kWh in a year.:shades_smile:

My system will pay for itself in less than 6 years

edit..and I'm in the N.E of the UK, not the sunny south

 

[D Skelton]

I have done all the things you have suggested, LED's, loft insulation and "A" rated windows.
(used my FITs payment to do them)
I also have a 4kW South west facing SP system. My usage has dropped from over 5000kWh a year (in 2011) to 2450kWh last year. Most of the savings come from my SP

This year from Jan 1st to now, I have generated 3560kWh and should be close to 3600kWh by year end.
Anyone with a 4kW, South facing system, with no shading should hit 4000kWh in a year.:shades_smile:

My system will pay for itself in less than 6 years

edit..and I'm in the N.E of the UK, not the sunny south

So you say you have an annual energy consumption of 5000kWh and you fitted a PV system of 4kW which should produce 4000kWh in a year? Why then has your energy consumption only halved? Shouldn't it have dropped by 80%?

 

[jerriais]

As my retinas are only converting 1.6%* of the light into electrical nerve signals I consider that to be very inefficient so I will now close them and try not to despair at what I've just read on this thread.

* I can cite many sources for that figure, probably.

 

[shanky887614]

So you say you have an annual energy consumption of 5000kWh and you fitted a PV system of 4kW which should produce 4000kWh in a year? Why then has your energy consumption only halved? Shouldn't it have dropped by 80%?

The consumption wont actually change only the bill from his energy supplier

 

[D Skelton]

The consumption wont actually change only the bill from his energy supplier

I meant in the sense that he is taking five and should be giving back 4, but is only actually giving back 2.5.

 

[shanky887614]

I meant in the sense that he is taking five and should be giving back 4, but is only actually giving back 2.5.

You get the fit rate even if he uses all the energy he generates so in effect he is getting paid for 4 but putting in a lot less into the grid

 

[longboat]

D Skelton...
Please return to your flat earth where global warming doesn't exist.

I welcome sensible debate but fail to understand why someone who is obviously so ill informed, skim reads google results and obviously has no interest in solar is posting here?

Your 'facts' are wrong...period. PV panels aren't 30% efficient...they are 15-20% efficient, but ********...you look at the headline % figure to base your opinion on.
Solar does work, is financially viable and is an important but often overlooked part of our future energy supply. These stupid comments are damaging, as there are too many other lazy, armchair experts out there who start quoting this crap as fact.

I take it you don't drive a car? They are obviously equally useless due to there 30% efficiency.

I'm posting this as I feel it is important that information posted online is factual. Anybody reading this thread in the future...please ignore ******* comments and do your own proper research.

Ken

I think this is the crux of your argument.
Only look at the glossy website's that have a financial intrest in you believing their dubious claims.
Ask yourself how often you leave a potential client's house hoping they dont do "proper" research?

 

[Gavin A]

I was using the figure of 'around 30%' because of a New Scientist article I was reading last week about the 'next generation' of solar panel. The fact is that in a few years it will be 40% and in many years to come potentially more. The exact value, whether 20% or 30% is not really the point, the point is that the value is low!

the point is that efficiency is largely irrelevant when the fuel source is free, abundant and virtually ever lasting.

I can't disagree with that. PV is better than nothing for sure, but for the cost??? I'd sooner spend the money on LED lighting, correct insulation and A rated windows and still have enough money left over to go for a beer, or a thousand, after fitting it all

it's not an either or option, for most of our customers solar PV is the next step after they've already done all of that.

From what I have seen and heard, I find these figures hard to believe, especially when the average light energy intensity in the UK on a south-facing roof is around 250 Watts per square metre (I can cite many sources for this figure). How is it possible for a 4kW system to produce 3600kWh per year???

1150kWh per m2 of insolation per year at our office according to PVGIS satellite data, multiplied by 26m2 array area for 4kWp of standard 250Wp panels = 29900kWh per year of solar energy available.

29,900 * 12% efficiency of conversion = 3588kWh

and the practical experience from hundreds of systems installed, and dozens actively monitored backs this up.

 

[D Skelton]

You get the fit rate even if he uses all the energy he generates so in effect he is getting paid for 4 but putting in a lot less into the grid

Exactly!!! Bingo!!! At last!!! This is the crime! Essentially, there are fellas out there (not all I must add) robbing the tax payer blind because they have fitted a 4kW system to a north facing and shaded roof. The system is producing precisely 0kWh per year but they still get the money for it! Granted this has changed recently and people are less able to cream off the system, but by god what a terrible idea! People should get paid for what they ACTUALLY produce, rather than what the installer says it will produce under standard test conditions!