payback time?

[subevo]

ive had a quote for a 1 kw installation.its £5500.inc grant.how many years before i make a profit.also just thinking most of the power will be produced whilst the family are at work.so the only things on in the house are the fridge freezer so is the generation not going to waste because at night the panels dont work and thats when you need  most of the electricity.wife says we will move in about 5 years so is it worth doing?

[martin]

Oh gawd, its one of those "where do you start?" questions - first of all, what are they offering for your £5,500?,  and the details of the grant, then we'll know what we're up against

[Amy]

Whats more, who is making the offer?

Some companies have a reputation, so knowing who will possibly explain what your dealing with

[billt]

Simple answer. You will never make a profit.

1kw peak array should produce about 750kwhr P.A., £75 worth of electricity at 10p per unit. Simple payback period over 75 years, much longer than any reasonable expectation of the equipment life.

If you believe in miracles and ROCs at a reasonable rate come into existence you might get that up to 40p per unit. That would bring the simple repayment time down to 19 years, assuming that no maintenance is needed and nothing breaks. Of course you've lost the use of your £5500 and won't be getting any interest on it so the actual repayment time would be much longer.

If you are going to move in 5 years you would be mad to pursue such a course.

http://www.retscreen.net/ang/home.php has software that lets you play around with various renewable energy scenarios to assess their value, if you feel like getting a more detailed view.

[billi]

Simple answer. You will never make a profit.

I do profit a lot , each day , like a small boy i walk to my solar controller and check what we have produced today ,
in the morning when the sun rises ( now very early ) or even its rainy, cloudy i walk to my solar controller and look at the production  each walk is a profit for me .... I have found a reliable friend  in my PV panels

If i would grid connect our system  in Ireland ( donot know the tariffs in the UK)

I would save about 17 cents per unit on my own bill and get 20 cents for my overproduction

If i would install a 5 kw  rated PV array  here  i would harvest about 4500 kwh (units)   a year

So for our needs we need 2800 kwh = 476 euro per year ( at 17 cents ) + 340euro (at 20 cents) = 816 euro per year

A 5 kw peak PV would cost me   18 thousand euro    , so  would need about 23 years to pay off ( if all works fine )

That doesnot sound too good , but  still i like my profit  from it and  knowing how most electricity is produced  in general here on the back and the exploiting of the country/globe  and knowing how much energy is wasted in the powerstations to produce one unit , as well that we will  have to find Alternative Ideas anyhow

I like my friend PV  and if the lights go out from the mains ....   we have a party


Billi

[Paulh_Boats]

Look at the roc thread:

http://www.navitron.org.uk/forum/index.php/topic,6789.0.html

peterc will soon get a 3.2% return on his investment....that is BETTER than any bank account in the world right now.

So forget all the nonsense about payback times which are impossible to predict as you don't know the future energy prices.

Investing in PV (at a competitive price) is better than leaving money in the bank.   

Which bit don't you understand?     .... and take the hardware with you if you move house.

-Paul

[billt]

If you assume that the original post is genuine, he does not appear to have any emotional attachment to the idea of PV and is only interested in the financial aspect so comments about how good it makes you feel are irrelevant.

3.3% may be a reasonable return on capital at the moment but future investment returns are just as unpredictable as future fuel prices and are quite likely to increase.

If the capital is invested you still have the use of it. Once you have bought a PV system the capital is lost. (Bear in mind that this will be a turnkey system so the value of the components is unlikely to exceed £3000 at retail prices, so the second hand value will be very low.)

It's all very well saying that he can take the system with him, but I rather doubt that the OP has your level of technical ability so he would have to pay someone to remove and reinstall the system. That's likely to £2-3000 each time he moves. More money down the drain.

I am well aware that there are many other reasons other than financial ones for installing renewable energy systems (I've spent rather a lot of money recently on such things and doubt that I'll get a return on them) but that is not a sufficient reason to suggest to everyone that raises the issue that payback is unimportant. (Why do you think that all these wind farms are being dropped? Conspiracy theories will be ignored.)

[billi]

Bad day ?  or 

I just made 5 kwh  today  and no monthly bill    , no paper,no bank, no worries 

sunny great day
 

comments about how good it makes you feel are irrelevant.

Sure .... sounds like real live or printed on a monthly bill   

Billi

[martin]

I think the spiritual side is overlooked myself - all that cosmic karma you're building up, all that clear conscience  - next time you see a polar bear cub, you can think "one of ours", knowing you helped preserve his habitat........ money? payback?, what sort of horrific world is that?.....the sooner we get round to following Bhutan's lead towards "gross national happiness", the better!
I'm with Billi 100%

[Justme]

I just made 5 kwh  today  and no monthly bill    , no paper,no bank, no worries 

Billi

How big is your array?

Most we have seen so far this year is 1.6kwh (111amph) from a 0.8kw (800watts) array.
Not sure what todays was will check in morning.

Justme

[billi]

How big is your array?

Justme i have only 1,6 kw PV installed , but we had very good weather the last three weeks

Here are the daily  kwh produced starting from yesterday back wards  ( thats the data from my solar charge controller )

5
3,8
6.3
3,0
7,5
4,9
6,7
6,6
4,2
3,7
7,2
5,5
5,7
6,3
2,2
7,3
3,0
4,4
5,0
0,5
1,6


Like said it was good weather 

Sure England and Ireland are not the best places for PV  and we miss the good feed in rates ( that is a political problem not one of the PV panel ) and a right feed in tariff would bring people on board that you never have thought would go for PV


If we think about PV only as a $ profit making idea , then why do people not install a PV other parts of Europe (one can rent roofs or fields ) were a feed in tariff  is granted for  20 years up to  50 cents a unit 
Sure England and Ireland are not the best places for PV  and we miss the good feed in rates
= fully paid after 10-12 years and then  make  money  and the panels are yours and will  later supply all your house needs , perhaps for longer then one needs them

So let me say  you install a 10 kw PV in South Europe   ( costs about 35000 euro without roof rent )
Generated ( at 12000 kwh per annum at 0,45 cents a unit  ) 5400 Euro per year  granted for 20 years = 108000 euro  harvested  .  So i only guessing  if you finance this  via  the bank and subtract all hidden costs  then you make about 50000 euro (guess)  and still have your PV after 20 years to supply free electricity and (big parts) of your heating later

Still an idea i have in the back of my mind  ( but mortgage is heavy on my back as well )

Billi

[Justme]

Yeh we have had good weather too but our site is not ideal & our panels are still not south facing yet. My post should have said 1.4kwh not 1.6.

This is our stats for last month

day             amph   kwh
01//4/2009         79     0.9 with a peek height of 0.37kw so just less than 50% of panel max
31/03/2009         42     0.5
30/03/2009      34   0.4
29/03/2009      84   0.2
28/03/2009      82   1
27/03/2009      96   1.2
26/03/2009      87   1.1
25/03/2009      72   0.9
24/03/2009      69   0.8
23/03/2009      42   0.5
22/03/2009      69   0.8
21/03/2009      48   0.5
20/03/2009      109   1.4
19/03/2009      111   1.4
18/03/2009      108   1.3
17/03/2009      96   1.2
16/03/2009      97   1.3
15/03/2009      84   1
14/03/2009      18   0.2
13/03/2009      65   0.8
12/03/2009      15   0.1
11/03/2009      71   0.8
10/03/2009      53   0.6
09/03/2009      61   0.7
08/03/2009      16   0.2
07/03/2009      32   0.4
06/03/2009      44   0.5
05/03/2009      45   0.5
04/03/2009      9   0.1
03/03/2009      29   0.3
02/03/2009      60   0.8
01/03/2009      24   0.2



I think I realy need to move the panels to south facing (we are 43 deg facing currently, south is 32 & west 48 so not to far out) & lift them from the current gentle slope to about 37-45 deg. But I guess most of the issue is the trees that reduce available time at both ends of the day.


Justme

[kristen]

"3.3% may be a reasonable return on capital at the moment but future investment returns are just as unpredictable as future fuel prices and are quite likely to increase."

Just to paint a slight more optimistic picture!

The money saved by using less electricity is tax free, so for a 40% tax payer represents a 66% hike on that (i.e. to have £3.30 in your pocket would have to earn £5.50)

If both interest rates AND fuel prices increase then the relative gain of this type of investment, compared to money-in-building-society, will remain similarly beneficial.

[billi]

Justme 

i did play around  with four  strings of PV ( four  with 400 watt )  and moved them  around (Nov. 2007)   

Had all four strings  at several locations  to test their performance  , i forgot about the idea of roof mounting them pretty fast  cause  to much west and too flat

ok we have space  so found a place on the ground  and optimized for spring and autumn now  thats suits us

 here one of my early tries  as a greenhorn ( still i am )  when i putted one string up that roof  ( the other strings  still on ground performed much better , so ended up with all on ground)


 Ladder a bid out of line     but managed

Billi

[Shay]

Yeh we have had good weather too but our site is not ideal & our panels are still not south facing yet. My post should have said 1.4kwh not 1.6.

This is our stats for last month

day             amph   kwh
01//4/2009         79     0.9 with a peek height of 0.37kw so just less than 50% of panel max
31/03/2009         42     0.5
30/03/2009      34   0.4
29/03/2009      84   0.2
28/03/2009      82   1
27/03/2009      96   1.2
26/03/2009      87   1.1
25/03/2009      72   0.9
24/03/2009      69   0.8
23/03/2009      42   0.5
22/03/2009      69   0.8
21/03/2009      48   0.5
20/03/2009      109   1.4
19/03/2009      111   1.4
18/03/2009      108   1.3
17/03/2009      96   1.2
16/03/2009      97   1.3
15/03/2009      84   1
14/03/2009      18   0.2
13/03/2009      65   0.8
12/03/2009      15   0.1
11/03/2009      71   0.8
10/03/2009      53   0.6
09/03/2009      61   0.7
08/03/2009      16   0.2
07/03/2009      32   0.4
06/03/2009      44   0.5
05/03/2009      45   0.5
04/03/2009      9   0.1
03/03/2009      29   0.3
02/03/2009      60   0.8
01/03/2009      24   0.2



I think I realy need to move the panels to south facing (we are 43 deg facing currently, south is 32 & west 48 so not to far out) & lift them from the current gentle slope to about 37-45 deg. But I guess most of the issue is the trees that reduce available time at both ends of the day.


Justme

You would really want to move that array Justme. My array currently is 660Wp, South facing and at 36 degree pitch (Ireland).
I got 2.2kWh today and 1.2kWh yesterday.