Solar Panel Guide Discussion

zeupater

nealh wrote: »

I have now evaluated 4 residential locations for Solar PV in England and I pass on my experience. If you are looking for a financial return you MUST take into account the precise 'aspect' of the roof', it's location and the technical characteristics of the array/inverter being proposed. The BRE SAP data that most good firms present is NOT sufficient. You should start with Google Earth using your post code to yet a rough idea on aspect.I then suggest you register and use 'compare my solar' or a similar site to get more INITIAL detail on the potential for your site. This is fiddly (but OK if you have used MS office type computer graphics) and only suitable for angled roofs but is a few minutes it gives you more data than most 'quotes'! Finally there are 2 software products out there which enable a projection of the revenue that will come from your system. They use LOCAL weather data and the current technical data from manufacturers (including the year on year system 'decay'). They are PVSol and PVSyst. Amazingly not many firms, including the 'installer of the year' evoenergy offer this. One that does is Greenheart energy, but they only cover the SE and only offer (top rated) Schott panels. A good location/array will give you an 11% return per year averaged over 25 years, including replacement inverter costs. (Others can be MUCH less). Remember the installation cost is basically the same for a small system as a just under 4Kw system so bigger systems offer a bigger return. Again anything which makes your location an 'easy' install should lower the price. Finally, England is NOT as good a location for Solar as Germany except in the Southern half and especially the ideal spot 'South of the North of the M25!' There are a LOT of dodgy firms out there, beware.

Hi

Alternatively, for free, you can use PVGIS which is a web application developed by the European Commission (http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php) ... you've already paid for it, so why pay again

Direct comparison of panels can also be done for free. Each of the major inverter manufacturers provide a planning tool to match inverter model to array size/panel model .... for example the SMA 'SunnyDesign' software available to download here .. http://www.sma.de/en/service/downloads.html

HTH
Z

mickyduck

Hi had a power cut yesterday while at work and returned in the evening to Webbox with glaring Red light indicating there was no communication with my router despite them both being on. Re booting the Webbox fixed that but the data from solar generation in the afternoon was not collected. Does anyone know if there is a way to retransmit data from the inverter (Sunny boy 4000) does it even retain any data? Secondly if the power is off does the generation meter still record power being generated from the PV array?
Thanks

furndire

As far as I know if you have a power cut, your panels are automatically shut off as well - so generation is zero.

bjohnson

furndire wrote: »

As far as I know if you have a power cut, your panels are automatically shut off as well - so generation is zero.

Well, it's still being generated but not exported to the grid. I don't know whether the inverter records the power produced even though it is not exported.

grahamc2003

bjohnson wrote: »

Well, it's still being generated but not exported to the grid. I don't know whether the inverter records the power produced even though it is not exported.

Can't see how that works! Where's the power being dumped in that case?. Surely, on a power cut they just go open circuit somehow (probably controlled by the inverter), so there'll be a voltage generated by the panels, but no current (and therefore no power).

bjohnson

grahamc2003 wrote: »

Can't see how that works! Where's the power being dumped in that case?. Surely, on a power cut they just go open circuit somehow (probably controlled by the inverter), so there'll be a voltage generated by the panels, but no current (and therefore no power).

Quite right! I was confusing voltage with current. I did do A level physics but it was fifty years ago.

thenudeone

furndire wrote: »

As far as I know if you have a power cut, your panels are automatically shut off as well - so generation is zero.

It's ironic but correct. It is to stop the power from your panels electrocuting any power workers who may be working on the grid, which is supposed to be switched off for their safety.

MarcusH

Hello all. I'm new to this forum, and have read the whole thread with much interest. I'm still undecided on whether to go for solar panels or not.

Seems to me that if it takes say ten years for breakeven, it's worth knowing what would happen if I sold my house.

Could the new owner inherit the tariff I was on, or would it just expire?

Doc_N

MarcusH wrote: »

Hello all. I'm new to this forum, and have read the whole thread with much interest. I'm still undecided on whether to go for solar panels or not.

Seems to me that if it takes say ten years for breakeven, it's worth knowing what would happen if I sold my house.

Could the new owner inherit the tariff I was on, or would it just expire?

This link might help:

http://www.energysavingtrust.org.uk/Generate-your-own-energy/Sell-your-own-energy/Feed-in-Tariff-scheme#FrequentlyAskedQuestions

Extract:

What happens if I move home?
Ownership of the technology is linked to the site and, therefore, in the case where a building or homeownership changes, the ownership of the technology would also transfer to the new owner.

KevinG

thenudeone wrote: »

It's ironic but correct. It is to stop the power from your panels electrocuting any power workers who may be working on the grid, which is supposed to be switched off for their safety.

On a more practical note, doesn't the inverter require a power supply in any case?