Solar Panel Guide Discussion

lanstrom

How's this for a close fit ...

Total panel width (6x 1602 mm + 20mm gaps) = 9,712 mm
Total width of house (outside wall to wall) = 9,730 mm

I am hoping the width of the roof eaves gives enough safety room. Are they about 250 mm ? If so then that gives me 259mm each side.

Studlea_Phatt_Katt

Studlea_Phatt_Katt wrote: »

An update on the Guardian Competition sponsored by PV Solar. (I appreciate this is not the purpose of this thread but this item started here.)


Update 27th September.

PV Solar surveyor visited today. Pleasant and very helpful chap, taking time to explain how things worked, the set up and so on. Interestingly, he was a qualified spark by trade, which was reassuring as he poked around in the meter cupboard and beneficial as he was able to ‘design’ the cable routing etc to have no internal disruption whatsoever, and no external routing either, even though our electric meter etc is on an internal wall.

To maximise the benefit of having the panels he took some time to see if a more aesthetically pleasing array could be arranged than that produced by the computers, although we and our neighbours aren’t really bothered, so we reverted to the computer design, but again good that he took the time to try different arrangements and explain to us the pros and cons.

Installation is looking to take place within the next week or two. The ‘kit’ will likely be delivered the day before and stored in our garage overnight, and possibly a scaffold will be required, which if the case, will be erected the day before also. This allows the team of Roofer, Labourer and Electrician to land on the job first thing and be done by lunchtime!

So far then, PV Solar UK, all good.

SPK.

ukmopar

Cardew wrote: »

Welcome to the forum.

There have been many posts on this subject, and whilst you are correct that some people take a very simplistic view on payback e.g. System costs me £10,000, I get £1,000 pa income thus payback is 10 years.

However there are many posts that discuss payback realistically and there are websites that have calculators that will work out payback based on your assumptions.

To work out a 'break-even' point you must invest all your annual savings year on year.

However there is still an element of 'wet finger in air' in attemting to calculate payback. You must guess:

Future inflation rates

Future electricity inflation rates

How much electricity you will use in house

Future interest rates on savings

cost of repairs(inverters etc) Roof problems.

Cleaning of panels

Degredation of panel performance.

Government intervention on FIT


As panels get cheaper, so payback periods shorten, and most of the informed comment in this thread guesses at 10 to 12 years.

IMO the best way to consider investment in PV is to treat it as an annuity.

Any suggestions on useful payback calculators would be useful, particularly ones that take account of the loss of interest from the capital invested.
I do agree that the interest earnt on the income from the panels should be included in the calculation.

Paul

keith_r59

ukmopar wrote: »

Any suggestions on useful payback calculators would be useful, particularly ones that take account of the loss of interest from the capital invested.
I do agree that the interest earnt on the income from the panels should be included in the calculation.

Paul

You could try this web site. I haven't used it so don't know how accurate it is.

http://www.pvsolarpanelcalculator.co.uk/

Studlea_Phatt_Katt

Studlea_Phatt_Katt wrote: »

Studlea_Phatt_Katt wrote: »

An update on the Guardian Competition sponsored by PV Solar. (I appreciate this is not the purpose of this thread but this item started here.)

Update 28th September.

PV Solar surveyor visited yesterday, and this morning we received a phone call from PV Solar UK, to arrange installation on Monday 3rd Oct. Quick or what?

So again, PV Solar UK, all good.

SPK.

lanstrom

keith_r59 wrote: »

You could try this web site. I haven't used it so don't know how accurate it is.

http://www.pvsolarpanelcalculator.co.uk/

I just put some details in as accurately as I could and it would seem I will be £100,000 richer in 25 years

Wahooooo :T

Just put the same details into http://www.energysavingtrust.org.uk/Generate-your-own-energy/Cashback-Calculator

They say I will only get £43,000 so I am going to believe pvsolarcalculator instead ;-) To be fair I dont think they take re-investment of the FiTs into account.

This one is pretty good ... http://www.solarguide.co.uk/solar-pv-calculator
That gives me £57,000 which is about as accurate as I would think it can possibly get with all the guesses involved.

keith_r59

lanstrom wrote: »

I just put some details in as accurately as I could and it would seem I will be £100,000 richer in 25 years

Wahooooo :T

Just put the same details into http://www.energysavingtrust.org.uk/Generate-your-own-energy/Cashback-Calculator

They say I will only get £43,000 so I am going to believe pvsolarcalculator instead ;-) To be fair I dont think they take re-investment of the FiTs into account.

This one is pretty good ... http://www.solarguide.co.uk/solar-pv-calculator
That gives me £57,000 which is about as accurate as I would think it can possibly get with all the guesses involved.

I've just put my own figures into http://www.pvsolarpanelcalculator.co.uk and, apart from it not taking account of panel degradation, it seems to be reasonably accurate for my system when compared with my own spreadsheet calculations.

lanstrom

keith_r59 wrote: »

I've just put my own figures into http://www.pvsolarpanelcalculator.co.uk and, apart from it not taking account of panel degradation, it seems to be reasonably accurate for my system when compared with my own spreadsheet calculations.

Care to share your stats ?

Did you put immediate depreciation as 100% and 'electricity cost increase' at 6% (I think I put 10%). I also left RPI at 3%.

Thanks.

keith_r59

lanstrom wrote: »

Care to share your stats ?

Did you put immediate depreciation as 100% and 'electricity cost increase' at 6% (I think I put 10%). I also left RPI at 3%.

Thanks.

Here you go....

start date: 2010-10-05
cost: 6600
interest(%): 3.3
tax(%): 20
output(kwh/yr): 1117
used(%):50
electricity cost(p/unit): 10.175
electricity cost increase(%): 6
immediate depreciation(%): 100
RPI(%): 3
generation tariff(p/unit): 41.3
export tariff(p/unit): 3

Produces a result of £28,685 for Solar.

My own spreadsheet calculations give me a result of £28,459.48 without panel degradation and £25,842.91 with 0.8% decreased output performance each year.

However it is all academic as I don't re-invest the FITs or invest the money saved on my reduced electricity consumption.

lanstrom

As part of my installation I am getting a Fronius IG 50 + (4 kWh).

I want to be able to read the previous months total generation from it every month. Is there a function built in to do this or should I use the export meter and make sure I read it at the same time each month ?

Or is it worth buying something like the 'Fronius Datalogger Easy' ?

Thanks.