Solar PV Panels

chrismarsden

That depends on system size?
July * 12? Not so much Sun in Dec surely?

When I said tariffs change in 4/2012, that is for installs AFTER then.

They have a total generation meter, that gives your 41.3p, then deemed export at 50% for now!!! Unless you have an export meter, rare at the moment aiui.

btw tried the est web site for their calculator - that IS independent.

zeupater

Cardew wrote: »

Using what estimates in the 7 boxes?

Hi Cardew / All

Regarding the 7 year payback on the reuk calculator ....

Just tried it out to see what 7 years would look like ....

4kWp system - predicted 3100kWh/Year (typical off south installation - no shade issues)
Electricity savings - £100/Year
Inflation (default) - 3%
Electricity price increase (default) - 5%
AER (default) - 4.5%
Tax (default) - 20%

For breakeven in year 7 the purchase price would need to be around £9200 ..... possible if you're in a mature european market, or MCS registered and fitting it for yourself, but at £2.30/Wp fitted something looks wrong.

Feeding the following system prices into the calculator with all other variables static the payback works out at ...

£12000 - Year 9
£14000 - Year 11
£16000 - Year 13
£18000 - Year 14

... and this doesn't include maintenance or replacement inverters, so possibly add another year or two to the figures above ...

To anyone reading this post who believes, or has been told, that a system at current UK price levels will breakeven within 7 years or even 9 years, please query the assumptions and do a little research .... payback has been discussed in detail on this forum, please take time to review the relevant threads .....

HTH
Z

zeupater

chrismarsden wrote: »

That depends on system size?
July * 12? Not so much Sun in Dec surely?

When I said tariffs change in 4/2012, that is for installs AFTER then.

They have a total generation meter, that gives your 41.3p, then deemed export at 50% for now!!! Unless you have an export meter, rare at the moment aiui.

btw tried the est web site for their calculator - that IS independent.

Hi

You'll find that Mcfi5dhc is really posting in jest whilst still querying the accuracy of the claimed saving, this being due to having had a similar size system generating for quite a while .....

HTH
Z

Cardew

zeupater wrote: »

Hi Cardew / All

Regarding the 7 year payback on the reuk calculator ....

Just tried it out to see what 7 years would look like ....

4kWp system - predicted 3100kWh/Year (typical off south installation - no shade issues)
Electricity savings - £100/Year
Inflation (default) - 3%
Electricity price increase (default) - 5%
AER (default) - 4.5%
Tax (default) - 20%

For breakeven in year 7 the purchase price would need to be around £9200 ..... possible if you're in a mature european market, or MCS registered and fitting it for yourself, but at £2.30/Wp fitted something looks wrong.

Feeding the following system prices into the calculator with all other variables static the payback works out at ...

£12000 - Year 9
£14000 - Year 11
£16000 - Year 13
£18000 - Year 14

... and this doesn't include maintenance or replacement inverters, so possibly add another year or two to the figures above ...

To anyone reading this post who believes, or has been told, that a system at current UK price levels will breakeven within 7 years or even 9 years, please query the assumptions and do a little research .... payback has been discussed in detail on this forum, please take time to review the relevant threads .....

HTH
Z

Totally agree.

You could also question two of the default settings.

The aim of the Bank of England is to get inflation down below 2% and that is supported by all political parties.

Is 4.5% on long term saving interest rates low?

Also what if you put the money in ISAs or had to borrow?

People totally ignore any potential repair costs, roof repairs etc in the calculations.

Some people with long term experience say it is essential to clean the panels of grime, bird droppings etc regularly; other say the raid will do the job.

Equaliser123

Cardew wrote: »

Totally agree.

You could also question two of the default settings.

The aim of the Bank of England is to get inflation down below 2% and that is supported by all political parties.

Is 4.5% on long term saving interest rates low?

Also what if you put the money in ISAs or had to borrow?

People totally ignore any potential repair costs, roof repairs etc in the calculations.

Some people with long term experience say it is essential to clean the panels of grime, bird droppings etc regularly; other say the raid will do the job.

Agree.

Not sure where the tax on the PV returns comes into it.

Cardew - as a matter of pure interest, do you have a system?

Mcfi5dhc

zeupater wrote: »

Hi

You'll find that Mcfi5dhc is really posting in jest whilst still querying the accuracy of the claimed saving, this being due to having had a similar size system generating for quite a while .....

HTH
Z

Guilty on all counts, sorry

However, if you could get your usage up to 75% (or in other words, your exported down to 25%), then I suppose you could get pay back in 7 years. Its a big suppose though, though strangely the free solar companies seem to think that is normal - so do estate agents in the Sheffield area. Actually, the EA's in Sheffield assume about 110% usage, with no exports, but thats a different thread for a different day...

Anyway, I'm not jesting this time, but 75% usage would be the only way you could do 7 years without scamming someone somewhere. To do this would take over your life, not something I would be interested in.

For newbies, this would mean:
Showering between 11am and 3pm instead of normal time - your boss may not like this.
Cooking your evening meal at about 2pm every day - you might get fed up of cold teas (you have zero chance of using the microwave ever)
Only washing your clothes when the met office predicts 2 hours of clear sunny sky. This may take several months over winter - your friends may not like your smell during this time.
Using the tumble drier only when it is blazing hot outside. Please note, your clothes will take 4 times longer to get dry, but hey, its free leccy,
Investing several hundred pounds on timers, standby savers, slow cookers (seriously, if you've never used one before, you'll use it like twice, don't bother - if you use one already, then thats fine, you'll be ok), and other crap that'll save you an additional £5 per year

Or

Just fit the panels and get on with life and other important things. Accept its a long-term investment, and it'll probably take a teeny bit longer than your spreadsheet spits out, but who cares. If its sunny, take the kids down to the beach.

M

PS - incidentally, for those people who have worked out how good/bad the £500 Homesun offer is, they won't have payback from the £500 in 7 years. Or ten. And thats using their own figures on their website.

Cardew

Equaliser123 wrote: »

Agree.

Not sure where the tax on the PV returns comes into it.

Cardew - as a matter of pure interest, do you have a system?

No I don't have a system.

The tax 'question' is relevant for the interest on any capital invested. The calculator compares a sum of money invested, and the income from PV similarly invested.

If you invest, say, £15000 instead of buying a system, the rate at which that money will grow depends on the interest rate and the tax you pay on that interest.

For instance if the £15,000 was invested in a non-earning spouse's name, you would pay 0% tax on the interest and the money would grow faster than for someone with highish income who had a marginal tax rate of 40%.

Cardew

Mcfi5dhc wrote: »

Guilty on all counts, sorry

However, if you could get your usage up to 75% (or in other words, your exported down to 25%), then I suppose you could get pay back in 7 years. Its a big suppose though, though strangely the free solar companies seem to think that is normal - so do estate agents in the Sheffield area. Actually, the EA's in Sheffield assume about 110% usage, with no exports, but thats a different thread for a different day...

Anyway, I'm not jesting this time, but 75% usage would be the only way you could do 7 years without scamming someone somewhere. To do this would take over your life, not something I would be interested in.

For newbies, this would mean:
Showering between 11am and 3pm instead of normal time - your boss may not like this.
Cooking your evening meal at about 2pm every day - you might get fed up of cold teas (you have zero chance of using the microwave ever)
Only washing your clothes when the met office predicts 2 hours of clear sunny sky. This may take several months over winter - your friends may not like your smell during this time.
Using the tumble drier only when it is blazing hot outside. Please note, your clothes will take 4 times longer to get dry, but hey, its free leccy,
Investing several hundred pounds on timers, standby savers, slow cookers (seriously, if you've never used one before, you'll use it like twice, don't bother - if you use one already, then thats fine, you'll be ok), and other crap that'll save you an additional £5 per year

Or

Just fit the panels and get on with life and other important things. Accept its a long-term investment, and it'll probably take a teeny bit longer than your spreadsheet spits out, but who cares. If its sunny, take the kids down to the beach.

M

PS - incidentally, for those people who have worked out how good/bad the £500 Homesun offer is, they won't have payback from the £500 in 7 years. Or ten. And thats using their own figures on their website.

Although I obviously agree with the thrust of your post - particularly the pay back on the Homesun schemes and the difficulty in using more electricity in the house, I don't believe the usage up from say 50% to 75% will have a big effect on the payback period.

For instance if you leave all the defaults in the calculator in place except the 'First year electricity savings predicted' which you change to £100, it calculates 13 years to payback.

Increase that £100 by 50% to £150 and payback is now 12 years.

All of the other variables, except fuel inflation rate, have a far greater effect because the value of electricity used in the house is only a fraction of the value of FITs.

Mcfi5dhc

Cardew wrote: »

Although I obviously agree with the thrust of your post - particularly the pay back on the Homesun schemes and the difficulty in using more electricity in the house, I don't believe the usage up from say 50% to 75% will have a big effect on the payback period.

I have to admit, I didn't really put much effort in to the calcs

Its a bit like, those people who modify their car really really slightly, with stuff from Halfords. I suppose their Mondeo could then do 180mph, but I really can't be [STRIKE]ars[/STRIKE] bothered working it out

malch

i have a quote for 12 Sharp panels with an inverter kicking in at 125V ( many don't kick in untill you start producing 200V ) giving a peak output of 2.16 Kw
my SAP Calculations are

number of panels 12

panel output 180 watts

peak system output 2.6 Kw (number of panels X panel output = watts divided by 1000 to = Kw)

solar input factor 1200

KWh/year 2592 ( system output X input factor)

orientation factor 93%

shading 1

SAP calculation 2410

i have other quotes ( upto £14,700 for same/simular system :shocked:) but the they all seem to come up with different figures for the solar input why the discrepancies? on this quote i will have paid for the system in 7.08 years.:beer: on other sites using the same installation but their solar input figures it will be 7.5 years.:j