Free solar panel discussion

Dave_Fowler

digitaltoast wrote: »

That's a good and fair way to look at it. What you didn't account for was the cost of the loan - I doubt very much whether that many people have instant access to £13k that they would be happy to take a gamble with, so a loan would be needed. So don't forget to factor in the interest.

So, you've got interest charged AND interest earned lost AND no access to your money if needed. Just something to consider.

It would be very difficult to justify getting a loan to finance the installation.

As you may have guessed from my previous postings, I have spreadsheets showing the daily output, FITs, estimated electricity savings using various assumptions about percentage usage etc. I have one column in the spreadsheet which assumes I had taken out a loan and financed the repayments from the FITs earned and from the calculated savings on the fuel bill on a day by day basis.

I can put into this spreadsheet any interest rate and / or any initial loan. Then using the data from my 3kWp system can calculate the profit/loss result. For instance, if I had got a loan at 8% interest, the loan would have to be £14,425 or less for me to have made any profit this year.

Suggest any interest rate and any loan value and I can use my figures to calculate the profit / loss for a similar installation in a similar part of the country.

Dave F

Cardew

Dave,
There are at least a couple of calculators that will forecast 'break even' point. However you have to estimate:

1. The interest rate on any sum borrowed, or lost on a bank deposit, over a period of 10-12 years. Bear in mind that to be accurate you have to estimate the interest rate each year, e.g 5%in year 1, 4.2% in year 2 etc.

2. Inflation rate over the same period, again for each year - not an average. Who knows even a negative inflation rate like last year.

3. Fuel inflation rate - as above

4. Savings for electricity used in house.

5. Cost of repairs to system - even cleaning(regarded by some as essential) Roof repairs?

Obviously they cannot be estimated with any degree of certainty but I suspect most people would think 10 to 12 years to break even is reasonable.

However that is not the point I was making; it is my contention that it is misleading to talk of a 'return' of x% as you are not comparing 'like with like' when the comparison is between the purchase of a PV system and a bank investment.

Dave_Fowler

It is true that there are several sites which predict break-even times. But I have not come across one which uses loan repayments based solely on the income from the panels and the penalties of interest compounded on interest during the months when the panel output falls below the necessary level to pay the interest due.

As far as inflation in concerned, this is certainly an area which can not be predicted and hence forthcoming increases or decreases in FITs rates. One thing that I am reasonably certain of is that fuel prices are highly likely to outstrip inflation and hence the savings on reduced energy bills will be of greater importance.

All my figures are able to do is make a calculation using actual generation figures and actual FITs payments and then produce, for this year only a calculation of the difference between loan interest and income generated. How one wishes to flex these figures for future years is open to debate and I totally agree that no one can predict what is going to happen.

Dave F

cathd6

Cardew wrote: »

cathd6,

There is plenty of evidence that some 'rent a roof' companies have resorted to the tactics of double glazing salesmen of yesteryear. They are making outrageous claims of potential savings; and by the evidence on here, having considerable success.

Hiya - completely agree with you. But I've not presented myself as arguing that this is what you can make. Far from it, I've said several times (I think unnecessarily) that you can't draw any conclusions from my statement of what we've saved, but also that if that's what people want then I'm happy to talk real numbers via PM. My original statement was a throwaway comment tagged onto the real point I was making that is now lost in the mists of time!

I don't think that a forum is an appropriate place at all to be trying to get an accurate idea of return, and would hope that people would realise that. I've now checked my output and the amount of the £100+ saving that can be verifiably attributed to the panels is... well it's good, and about what I was expecting. But it's meaningless isn't it? Different roofs, different locations, different systems, different patterns of usage, not forgetting the fact that what I've SAVED depends on my original bill and tariff. I'm not happy to post real data here, partly because this is a well-trolled board but partly because I don't think it's appropriate precisely because there are those who seek to mislead and those who are easily misled.

If you are looking for advice you should be getting forecasts from local companies of good reputation, who can put you in touch with satisfied customers in your area. You could do a lot worse than look at the various case studies out there - this is quite helpful: http://www.uksolarcasestudy.co.uk/

Discussion forums are only for very broad statements.

Dave_Fowler

cathd6 wrote: »

I don't think that a forum is an appropriate place at all to be trying to get an accurate idea of return, and would hope that people would realise that. I've now checked my output and the amount of the £100+ saving that can be verifiably attributed to the panels is... well it's good, and about what I was expecting. But it's meaningless isn't it? Different roofs, different locations, different systems, different patterns of usage, not forgetting the fact that what I've SAVED depends on my original bill and tariff. I'm not happy to post real data here, partly because this is a well-trolled board but partly because I don't think it's appropriate precisely because there are those who seek to mislead and those who are easily misled.

If you are looking for advice you should be getting forecasts from local companies of good reputation, who can put you in touch with satisfied customers in your area. You could do a lot worse than look at the various case studies out there - this is quite helpful: http://www.uksolarcasestudy.co.uk/

Discussion forums are only for very broad statements.

By posting actual data and presenting actual situations allows others to make evaluated judgements. It is statements given without any backup data which are actually misleading and liable to make people arrive at the wrong conclusions.

I find it difficult to understand your reasoning when you say 'I'm not happy to post real data here, partly because this is a well-trolled board but partly because I don't think it's appropriate precisely because there are those who seek to mislead and those who are easily misled' and then follow it up by giving a link to a site where people do give actual readings and data and say 'You could do a lot worse than look at the various case studies out there'.

You will find on that website someone who has an identical PV installation to mine with a set of figures I believe are quite accurate.

Dave F

zeupater

cathd6 wrote: »

Hiya - completely agree with you. But I've not presented myself as arguing that this is what you can make. Far from it, I've said several times (I think unnecessarily) that you can't draw any conclusions from my statement of what we've saved, but also that if that's what people want then I'm happy to talk real numbers via PM. My original statement was a throwaway comment tagged onto the real point I was making that is now lost in the mists of time!

I don't think that a forum is an appropriate place at all to be trying to get an accurate idea of return, and would hope that people would realise that. I've now checked my output and the amount of the £100+ saving that can be verifiably attributed to the panels is... well it's good, and about what I was expecting. But it's meaningless isn't it? Different roofs, different locations, different systems, different patterns of usage, not forgetting the fact that what I've SAVED depends on my original bill and tariff. I'm not happy to post real data here, partly because this is a well-trolled board but partly because I don't think it's appropriate precisely because there are those who seek to mislead and those who are easily misled.

If you are looking for advice you should be getting forecasts from local companies of good reputation, who can put you in touch with satisfied customers in your area. You could do a lot worse than look at the various case studies out there - this is quite helpful: http://www.uksolarcasestudy.co.uk/

Discussion forums are only for very broad statements.

Hi Cathd6 / All

Considering the link supplied above, did you have a look at the energy generated in Dec/Jan/Feb v Mar/Apr/May for all of the systems as they simply confirm what I and others have posted regarding likely generation and potential savings ?.

I'm pretty sure that there is a reason for the deliberate obfuscation in the above referenced post, particularly "the £100+ saving that can be verifiably attributed to the panels is... well it's good, and about what I was expecting" .... that's probably the worst journalistic-type mumbo jumbo that I've seen in ages, bordering on what I would expect from a politician attempting to cover up a recent error in judgement.

Regarding the position on savings that you "don't think it's appropriate precisely because there are those who seek to mislead and those who are easily misled." ..... that's exactly the point that everyone seems to be trying to convey, being based on maintaining that £100 saving on imported electricity during a period Dec'10 to Feb'11 with a 4kWp system is misleading, as is claiming that a saving of £400 over a year, without qualification of an atypical usage pattern, is possible.

HTH everyone else
Z

Cardew

cathd6 wrote: »

Hiya - completely agree with you. But I've not presented myself as arguing that this is what you can make. Far from it, I've said several times (I think unnecessarily) that you can't draw any conclusions from my statement of what we've saved, but also that if that's what people want then I'm happy to talk real numbers via PM. My original statement was a throwaway comment tagged onto the real point I was making that is now lost in the mists of time!

I don't think that a forum is an appropriate place at all to be trying to get an accurate idea of return, and would hope that people would realise that. I've now checked my output and the amount of the £100+ saving that can be verifiably attributed to the panels is... well it's good, and about what I was expecting. But it's meaningless isn't it? Different roofs, different locations, different systems, different patterns of usage, not forgetting the fact that what I've SAVED depends on my original bill and tariff. I'm not happy to post real data here, partly because this is a well-trolled board but partly because I don't think it's appropriate precisely because there are those who seek to mislead and those who are easily misled.

If you are looking for advice you should be getting forecasts from local companies of good reputation, who can put you in touch with satisfied customers in your area. You could do a lot worse than look at the various case studies out there - this is quite helpful: http://www.uksolarcasestudy.co.uk/

Discussion forums are only for very broad statements.

I am sorry but I really cannot understand what you are trying to say in this post.

It appears to me that you are still maintaining that £100 saving from PV in a winter quarter was achieved; but will only let people know by PM.

Why is it inappropriate to post data here and yet give another reference to a website - that incidentally has got contributions by Nang requesting them from this forum.

Lastly, the whole point of everyone challenging your posts was because they were likely to mislead.

cathd6

Now I've got everyone's back up by undermining the forum

But it's true. If I had posted that I had made £40 in 5 months then that statement would likely have gone unchallenged. No matter that it's no more helpful to anyone, or more likely to be accurate. There is a big difference between this forum and the sites that are gathering data, in that they provide very explicit detail. This is more like a conversation in a pub. I don't mean to suggest that some of the participants are not well-informed - clearly there is a good knowledge base (not that it's necessarily obvious from a couple of visits who you can trust). But if you were making what is really quite a huge decision then you need a lot of accurate data for comparison. Even if you could glean comparable data from this forum, are you really going to trawl through 100+ pages of junk and spats to do so?

The reason I'm happier to have a 1-on-1 is because I can give a lot more personal detail which I think is necessary, but then I'm getting the message that maybe I'm particularly cautious both in terms of how much information I am happy to have in a particularly "leaky" part of the public domain and in how much research I would consider appropriate before investing.

And to put you out of your misery, 72. That's the portion of the reduction in what we forked to the electricity company that quarter which I'm completely satisfied was due to our own generation.

Huge disclaimer, flashing warning lights. The only conclusions I would expect anyone to draw from that is that a) I'm happy and b) everyone's situation is different.

To add a point of personal opinion, I don't think that rent-a-roof schemes are a good idea for individual private households.

On a more interesting topic which is closer to the reason I first posted!! what do people think about yesterday's press on the falling cost of solar panels which would make non-subsidised solar viable in the near future? To a layperson this would appear to be a cautiously optimistic sign that FIT was having the desired effect.

cathd6

Dave_Fowler wrote: »

You will find on that website someone who has an identical PV installation to mine with a set of figures I believe are quite accurate.

Dave F

My point exactly. :cool: Thanks.

Dave_Fowler

cathd6 wrote: »

My point exactly. :cool: Thanks.

What point? - Sorry, I think I missed it.
Dave F