Solar PV...Still worth it?

silvercar

The price includes the improvement in the anchoring of the summer house roof, so difficult for comparisons I would guess.....

but anyway the quote is £9k.

This forms part of the blurb:

Income and expenditure
Investments: 8,990.00 £
Operating Costs: 8.99 £/a
Other Income/Savings: 218.00 £/a
Feed-in Payment Received in First Year: 643.40 £/a
Results According to Net Present Value Method
Net Present Value: 19,713.25 £
Payback Period: 9.7 Years
Yield: 10.1 %
Electriciy Production Costs: 0.10 £/kWh

silvercar

There is a second quote for a 3kw system on the main house for 12 panels with a Fronius International FRONIUS IG Plus 30 V 3kW inverter. This would be at -20 degrees, 37 degree incline. The cost here is £7k (no extra work needed).

Income and expenditure
Investments: 6,990.00 £
Operating Costs: 6.99 £/a
Other Income/Savings: 160.00 £/a
Feed-in Payment Received in First Year: 472.96 £/a
Results According to Net Present Value Method
Net Present Value: 14,090.51 £
Payback Period: 10.2 Years
Yield: 9.5 %
Electriciy Production Costs: 0.11 £/kWh

albyota

silvercar.....I must ask.....have you had the EPC done for your house yet?

silvercar

albyota wrote: »

silvercar.....I must ask.....have you had the EPC done for your house yet?

No, because the people installing the PVs said they arrange it as part of their work.

They said it would be the first thing they do, so I'm guessing their assessor will do an EPC and let them know if adding the PVs won't bring it up to a D rating.

Martyn1981

silvercar wrote: »

The price includes the improvement in the anchoring of the summer house roof, so difficult for comparisons I would guess.....

but anyway the quote is £9k.

This forms part of the blurb:

Thanks, just interested to see how prices are going. No idea what the other works are, but £9k can't be too bad.

Not that this really matters, but I can't figure out those income figures £218 & £643.

The £218 may be leccy savings, and it's not unusual to be a little optimistic, maybe £100 (£70 to £150) would be a safer bet till you see how it's going.

The £643 is throwing me though. They (and I) reckoned about 3,500 units, so that would be;
FITs 3,500 @ 21p = £735
Export 1750 @ 3.2p = £56
Total £791 (approx) plus leccy savings.

Sorry to be a party pooper, though in fairness, my total is slightly higher. Just thought there was something odd.

Back to the fun, if you decide to go for it, when are you thinking, or are there more quotes and haggling to go first?

Mart.

silvercar

We are heavy users of electric, so I reckon on the savings being above average.


The company comes well reccommended from friends who do an excessive amount of research, so I don't know if we would look elsewhere, may haggle on price if we can do so without compromising on job quality.

We also have the cost of removing two trees, if we go for the shed roof option (4kW); one is dead but the other is an oak that is not brilliantly positioned or that exciting a specimen, but there is an irony in removing a tree to make way for PVs.

Also considering how the house will look from the road with one side covered in PVs. Classic 1930s detached house with ridged roof, not sure if PVs don't look very out of place.

Lots to consider.......

Martyn1981

seagull09 wrote: »

My guess is that the £218 is the combined totals of the electricity saving and the 3.2p deemed export, but the £643 FIT is puzzling, that figure results from around 3000kWh grid feed-in.

I think you're right about the £218, making that a generous amount, but certainly possible since Silvercar said they are high users.

Your mention of 3,000 units got me thinking. Sorry, just can't help trying to work things out! Does this sound rational:

They've said it could generate around 3,500 units, but have quoted a FITs income closer to 3,000. I believe that companies can advise on potential gen, but can only quote against the Sheffield Uni. research results. So ......

Choosing Sheffield on PVGIS, and leaving it on classic (not climate), I get 1,570 units for azimuth -20, and 1,400 units for azimuth +70. Total 2,970units.

Q.1 does this make sense?
Q.2 do I need to get a life?

Mart.

PS Silvercar, at this stage in the PV install world, recommendations are priceless, certainly for peace of mind. I think you've got a good plan. M.

PPS. My gen in Cardiff (similar solar levels to Heathrow) is a good 10 to 15% more than quoted using govt/MCS rules and guidelines. M.

silvercar

We are still deliberating.

OHs feeling is that the summer house may not last as long as the PVs! and he is reluctant to chop down the oak tree.

I'm not sure I can live with PVs on the front roof of my house.

But those are soft decisions that we need to make ourselves.

Hard decisions that you guys may be able to help with:

3kw system against 4kw: obviously the FiTs would be lower, but would it be fair to say that we would use more of the generated electric ourselves, therefore the cost difference overall is not a simple 3:4 ratio? ie can I assume that we would use a higher proportion of the generated electric and so save nearly the same amount on our electric bill.

So I'm thinking that I'm generating 75% of a 4kW system and using say 90% of the 4kW system?

The costs were £7k for the 3kW and for the 4kW it was £9k + assumed £1.3k for tree removal = 10.3k.

EricMears

silvercar wrote: »

would it be fair to say that we would use more of the generated electric ourselves, therefore the cost difference overall is not a simple 3:4 ratio?

If you work at it really hard, you might be able to use all the electricity you generate.

More likely scenario is that whether you choose the 3kw or 4kw system the actual reduction in your 'paid for' units will be approximately the same.

I would however expect that your marginal return on one extra kw's worth of panels would be rather better than on the first three (won't take significantly longer to install or need any extra scaffolding etc).

Seems a shame (never mind the expense) to kill off a mature oak ! It may not be "that exciting" now but with a bit of pruning it might pick up in another hundred years or so.

What's your objection to using the house roof ? You'd never see the panels from indoors ; seldom from front or back garden and probably wouldn't even bother looking at your own roof as you drive into your road.

WestonDave

You probably need to analyse when you are using electricity currently to determine how much of your generated electricity you will save. I know for instance that a big chunk of ours goes via a 10KW electric shower mostly used early in the morning. That leads to two things - firstly even if 4kw of panels is running at peak I'm still going to be importing 6kw to run the shower, and secondly at 6am there isn't much of the year when the panels will make much dent on the electricity usage. (I can however possibly change my showering habits). Similarly you won't save much on the 20% of electricity typically used for lighting for obvious reasons.

In terms of the different systems, the wholesale cost of a panel is around £200 (£300 maybe for some of the more expensive panels) so to move from a 12 panel 3kw system I'd expect to pay another around £1000 to get to a 4kw system so in your case the diminishing effect of the fixed costs (scaffolding etc) isn't working as well as it could.

In terms of the summerhouse, its worth bearing in mind that the panels you buy are guaranteed to produce 80% of rated output for 25 years however that doesn't make them a total write off at year 25 - they will go on producing electricity for years after that, albeit at an ever diminishing rate. I'd be therefore a bit wary of putting them on a structure which is not likely to last at least 25 years as you won't get the full potential return out of them. I can see that putting them on the front of the house is a step further than putting them on the back but its still the better non emotional option. As you say however its a soft decision that only you can make. I'm fortunate in that my two sides are both away from the road so I don't have so much of an issue over looks.

(Just to update - EPC inspection done Saturday, contract papers arrived same day - just need some head space tonight to sign them off and get things moving. EPC should be a D easily apparently.)