Solar Panel Guide Discussion

zeupater

mickyduck wrote: »

No problem with the tea....
This is what the PVGIS gives me

Location: 51�14'30" North, 0�44'9" West, Elevation: 69 m a.s.l.,

Thanks

Solar radiation database used: PVGIS-classic

Nominal power of the PV system: 4.0 kW (crystalline silicon)
Estimated losses due to temperature: 7.4% (using local ambient temperature)
Estimated loss due to angular reflectance effects: 3.2%
Other losses (cables, inverter etc.): 14.0%
Combined PV system losses: 22.9%
Fixed system: inclination=24�, orientation=0� MonthEd Em Hd Hm Jan 3.511091.0733.2 Feb 5.991681.8451.5 Mar 8.692692.7284.4 Apr 13.103944.23127 May 14.604544.83150 Jun 14.904464.98149 Jul 15.104695.10158 Aug 13.704254.61143 Sep 10.503153.44103 Oct 7.032182.2469.5 Nov 4.361311.3540.4 Dec 2.6883.10.8225.3
Yearly average 9.54 290 3.11 94.6 Total for year 3480 1130

Hi

Small world, I've spent quite a few hours in the Swan Inn at Ashvale, decent beer, a bit pricey compared to my local though ....

Anyway, the SMA SunnyDesign software doesn't have the facility to resolve the meteorological data down to exact location so you'll just need to select Northern Europe/UK/London, it'll be close enough to compare panel/inverter combinations and calculate cable losses. The ability to create a location only allows a location name to be entered against a particular city's dataset.

Your PVGIS output above is using the classic dataset, this is based on averaging historical readings from groundstations and guestimating the insolation between them. The 'CLIMATE SAF - PVGIS' dataset is newer and based on averaging satellite observations down to a much smaller resolution and should be more accurate, especially in hilly areas .... this may not be the case in your particular case considering that the local met station is only about 2 miles away

When fitted you could adjust your PVGIS installed capacity to reflect the flashtest figures for you particular panel pack as delivered which will give a more realistic target, but don't forget that the panel performance will degrade over time ..... you could alternatively see this as a way to introduce a little frustration when the weather restricts production, but remember, it's only a target, it makes absolutely no difference to the actual generation .....

HTH
Z

Elainemary

Just a quick question for Gizmosmum - have you reached your target of wind and water tight by September 2011? Because if you haven't you're running out of time.

zeupater

digitaltoast wrote: »

...... Anyway, talking of selfbuilder, they've got a PV Special this week:
http://www.selfbuilder.tv/index.php

Again, I'm not convinced of some of the numbers bandied about in the show. If you have 15 mins spare I'd be interested to see what you think. .....

Hi

Figures generally seem to be okay .... I did think that the article was a little contradictory though ... effectively saying 'buy quality/known makes with a track record which are likely to be around when you need them', then showing a virtually unknown panel manufacturer because thir product is cheap and a new technology microinverter from a recent startup company ... :wall:

Anyway, if you watch it you'll probably notice the flex/wobble on the panel as they're talking about it, and notice the absence of a strengthening/supporting bar on the back of the panel .... and on the microinverters, these are the Enecsys units where the 300year MTBF is being discussed on another thread ... I'd still like to know whether the warranty would cover the cost of scaffolding for access to the roof and the labour involved in panel removal and replacement .... this better warranty on microinverters could end up being a nice little earner for the installers, moreso if the original manufacturer goes to the wall .....

Note also the MCS installer warning of the cowboy tactic of 'overestimating' the payback, whether 'unintentionally' or not !!

Generally a decent 30 minute watch

HTH
Z

zeupater

mardycow wrote: »

I am very interested in these solar pv panels, Had a guy from Carbon Legacy come out yesterday to quote me for about 13 panels, according to his figures he reckons if i spend £10,500 ish i would earn about £1700 pa from the generated and fed back electricity. Apart from all the previously mentioned ethical and political issues, does this seem like a good deal and has anyone any knowldge of this company or a better one?

Hi

What size panels are they talking about ... I'd be very surprised if a 13 panel system costing £10.5k would earn & save £1700pa using the SAP calculation which MCS installers must use in their quotations ... was the guy wearing a stetson ?? .... if you post more detail someone will help to see if it's realistic ...

See the selfbuilder video referenced in digitaltoast's post above(/below?)

HTH
Z

mardycow

the panels are german Solarworld, and the system quoted 3.185 incl an Italian inverter and a generator meter. i think the panels are about 1 m in size. not had all the details emailed through yet.

John_Pierpoint

zeupater wrote: »

Hi

Figures generally seem to be okay .... I did think that the article was a little contradictory though ... effectively saying 'buy quality/known makes with a track record which are likely to be around when you need them', then showing a virtually unknown panel manufacturer because thir product is cheap and a new technology microinverter from a recent startup company ... :wall:

Anyway, if you watch it you'll probably notice the flex/wobble on the panel as they're talking about it, and notice the absence of a strengthening/supporting bar on the back of the panel .... and on the microinverters, these are the Enecsys units where the 300year MTBF is being discussed on another thread ... I'd still like to know whether the warranty would cover the cost of scaffolding for access to the roof and the labour involved in panel removal and replacement .... this better warranty on microinverters could end up being a nice little earner for the installers, moreso if the original manufacturer goes to the wall .....

Note also the MCS installer warning of the cowboy tactic of 'overestimating' the payback, whether 'unintentionally' or not !!

Generally a decent 30 minute watch

HTH
Z

About 6 - 9 months ago we on MSE were all looking at a video of an American installation, where every panel had its own micro inverter
(tucked underneath on a hot felt roof: 25 year life expectancy on the roof let alone the inverter?)

I think the "plug and play" installation on the roof is the way the industry will go - [When I was a kid TV's were a jumble of wiring and valves - then they went modular - the repairman isolated the faulty plug in module and replace that - then the Japanese designed such reliable integrated TV's, that the TV was still operating, when a newer better technology made it obsolete - as a owner of a bungalow roof, do you think the thought police would allow me to remove and plug in a replacement panel/inverter - like being allowed to replace a light bulb in the bathroom?:eek::D]

Lotus-eater

This is very interesting for me as I've just had British gas round to give me a quote for me buying the panels and a free fit job.

I was quoted for a 3.2 KW system, which he said fits on our roof, £11.999 for everything.

The figures he went through were apparently industry wide standard.
Predicted energy produced, would be 2737 KWh per year, which would give me atm £1176 a year from FITs.

Now he worked out that I could use 70% of that myself as I'm at home during the day (I think 50% at best is achievable tbh) and that would be £248 off my electric bill. (Or £177 for 50%)

plus I think he said, I get 3p per unused unit.

The main question I have for you all, is the quote a reasonable one? It's alot cheaper than a few months ago it seems.

It works out to me at an incredible repay of 11.2% per year at the 50% useage. This seems a bit too good to be true. What could go wrong?

thenudeone

For £12k you could probably get a 4kW system by shopping around, which would be even better!
You will get 3.1p per unit for the 50% of your generation that is assumed to be exported. You'll get the same amount even if you export more or less than this, which is why shifting your usage to export less and use more of your production, is important.

What could go wrong?
It could be less sunny that expected.
Sooner or later something will break and need replacing -probably the inverter.
Panels could get damaged by snow or stone-throwing youths
etc.

But probably still worth it!

zeupater

John_Pierpoint wrote: »

About 6 - 9 months ago we on MSE were all looking at a video of an American installation, where every panel had its own micro inverter
(tucked underneath on a hot felt roof: 25 year life expectancy on the roof let alone the inverter?)

I think the "plug and play" installation on the roof is the way the industry will go - [When I was a kid TV's were a jumble of wiring and valves - then they went modular - the repairman isolated the faulty plug in module and replace that - then the Japanese designed such reliable integrated TV's, that the TV was still operating, when a newer better technology made it obsolete - as a owner of a bungalow roof, do you think the thought police would allow me to remove and plug in a replacement panel/inverter - like being allowed to replace a light bulb in the bathroom?:eek::D]

Hi

I remember the exact video and seem to remember that the roof was a very shallow angle and there was no regard for H&S at all being a ladder and walk installation (Do they actually have H&S legislation in the USA ?) .... the issue in this country is that the lunatics in parliament keep passing legislation which is designed to create and protect trade jobs .... I know someone who is well qualified in keeping aircraft worth tens of millions of pounds in the air and could strip a jet engine and rebuild it but isn't allowed to service his own gas boiler ... I know another engineer who is responsible for large generating equipment who isn't qualified to change a plug in his own house, it's always a hot topic around the bar at the local so if there's an issue with access which an installer can use to their own financial advantage by hiding behind some relevant legislation (H&S working at heights etc) they surely will .....

I like the idea of modular parallel systems, I just don't like the idea of the electronics being on the roof if it's not necessary but can easily understand why installers would .... the installation boom will end eventually so there must be some thought/planning of future revenue streams

HTH
Z

Lotus-eater

thenudeone wrote: »

You will get 3.1p per unit for the 50% of your generation that is assumed to be exported. You'll get the same amount even if you export more or less than this, which is why shifting your usage to export less and use more of your production, is important.

Could you explain this please, I don't really understand what you are saying. I thought that the whole thing was measured and they knew exactly the amount you used?

I have about the right size roof for a 3.2 kw system looking at the way he worked it out. No more space for a bigger system.
So I'd be looking at getting a cheaper price. I just don't know where to start tbh, seems to be so many cowboys around.

He did say that about the only thing that could break would be the inverter, at a cost of about £1k he said, but that it should last 10 years, but had a warranty of 5 years.


The only other thing, is that I know the roof tiles may need replacing in a few years, which makes it a difficult decision.

Oh and he said they use Sharp panels, is there anything about the makes of panels I need to know?