Solar Panels

Mistral001

irishjohn wrote: »

Hi Folks - Installed panels mid November 2012

Statistics so far

Used to pay Power NI £51 monthly DD for electric

Just had Airtricity bill for last two months - £48 in total

Amount of electricity generated by panels - 1518 units

Payment due for these units @ 17p = £258

Amount of electricity exported to grid - 1040 units

Export Payment due for these units @5p = £52

Approximate payment due from NIE for 7 months = £310

My electricity use from the grid has reduced to 5 units a day average - was 10 units a day - and am now probably using more electricity during daylight when before I would have been economising.

So electricity bill has halved over 7 month period, and income generated is approximately £500 for 7 months

Install cost was £7000 - I am happy with these results so far

Has this been subsidised by a grant in the way home insulation is subsidised?

guiriman

saverbuyer wrote: »

You could also pay off higher interest debt with the 8500. If you mortgage was 25 years at 6%, pay this off the balance and you'll effectively save £18,000 over the full term.

Now into my fourth year at 1.14% No interest whatsoever in paying that off!

irishjohn

Mistral001 wrote: »

Has this been subsidised by a grant in the way home insulation is subsidised?

I just missed out on the grants last year so I re-negotiated the cost with the supplier

irishjohn

Well folks - this morning is the 1st anniversary of using my solar panels to generate electricity. I can now give you an accurate summary of costs versus benefits. I have calculated this on the basis of the meter readings for 12 Nov 2012 and 2013. The payments received are calculated on the figures for this calendar year but in reality they are paid out at different times of the year for the previous 12 months.

System is 16 panels and was estimated to generate 3600 units per annum.

My historic use of units has been 3600 units for 3 bed detached house.

Cost to install was £7000

3668 Units generated by panels
2513 of those units exported

1145 units of generated free electricity used by me

3647 Total amount of electricity used by me (1145 free and 2502 from grid)

So I have obtained about 30% of my electricity from my solar panels. To buy that electricity would have cost me £170

My payments work out as follows

£647 ROC (Renewable Obligation Certificate) payment at 17.64p for every unit generated.
£136 additional payment for electricity not used by me and exported to grid at 5.41p per exported unit.

Added together my payments for generating electricity and the savings from using free electricity - the value of the panels for the first year has been £950 approximately.

I was uncertain about paying the capital out but it seems to have paid off for me - I will now try and increase the amount of free electricity I use in daylight hours and reduce the electricity I have to pay for when the daylight fades. A good outcome for me I think.

waltsalt

Nice work irishjohn. Thanks for the feedback.

saverbuyer

Thanks for the figures. It's great to get some real life examples.

Payback (including lost interest) is probably 10 or so years?


Much better than I would expect. It looks like you have had similar generation in summer and winter.

irishjohn

saverbuyer wrote: »

Much better than I would expect. It looks like you have had similar generation in summer and winter.

Mid November until end of May was 1500 approx and June until Mid November has 2150 so I guess 30% more generated while in British Summer Time.

motorguy

irishjohn wrote: »

Cost to install was £7000

the value of the panels for the first year has been £950 approximately.

7.36 years ROI.

My estimate at 7 years wasnt far off then. :cool:

Thats a great saving. Its definitely something we would look at doing in the future. We've a very energy efficient setup at the moment so it would make sense for us to look at reducing the remaining costs via photovoltaic.

motorguy

saverbuyer wrote: »

Much better than I would expect. It looks like you have had similar generation in summer and winter

We've solar water heating and i was surprised to hear the pump kick in on saturday. The reading on the tubes on the roof was 50 degrees which bodes well for photovoltaic during autum / winter months.

saverbuyer

motorguy wrote: »

7.36 years ROI.

My estimate at 7 years wasnt far off then. :cool:

Thats a great saving. Its definitely something we would look at doing in the future. We've a very energy efficient setup at the moment so it would make sense for us to look at reducing the remaining costs via photovoltaic.

Need to take account of the loss of capital cost but still less than ten years is much better than I expected.

IrishJohn, what sort of inverter guarantees are they offering nowadays?

I was reading the other day that panel costs have dropped 50% since 2009. If that trend continues I'd definitely consider solar PV.