Most optimistic Annual Yield figures - PVGIS or PVSOL?

[confounded]

You may well see it - however, you certainly shouldn't be predicting it.

Absolutely, we have systems that could achieve the 4400 in a year but to base the 25 year payback on it is crazy.

 

[SolarCity]

Absolutely, we have systems that could achieve the 4400 in a year but to base the 25 year payback on it is crazy.

Crazy and against REAL rules. Not that that seems to matter.

 

[liquidity]

There's poster on navitron who is reporting just over 4900 kWh in 2011 from a system in Littlehampton - 17 Sharp 235s with a 4000TL. Wonder what he would have got with Sanyo panels?

 

[SolarCity]

4,900?! I don't have any annual figure yet for my systems with TL inverters so we'll see how they come in.

 

[tlsambo]

I've run Winaico Panels on Penzance weather with a Fronius IG4.0 and got 4173. This is the best combination I know of (south facing, 37 degree roof) for PV Sol. Unless there is more irradiation on the Channel coast? This is the best combination for Cornwall that I know of. We keep a league table of panels which we run on an optimised roof on Plymouth weather data so we can compare them on a level playing field. We run each panel with Power One, SMA and Fronius inverters.

It is interesting to see the gaps between panel manufacturers close or widen depending on shading and orientation variables too!

If anyone else runs some better figures I'd be keen to know what combinations you've used.

 

[whlphil]

I've run Winaico Panels on Penzance weather with a Fronius IG4.0 and got 4173. This is the best combination I know of (south facing, 37 degree roof) for PV Sol. Unless there is more irradiation on the Channel coast? This is the best combination for Cornwall that I know of. We keep a league table of panels which we run on an optimised roof on Plymouth weather data so we can compare them on a level playing field. We run each panel with Power One, SMA and Fronius inverters.

It is interesting to see the gaps between panel manufacturers close or widen depending on shading and orientation variables too!

If anyone else runs some better figures I'd be keen to know what combinations you've used.

What losses do you assume and what size of cable, albedo, height above ground, mismatch, pollution etc? makes a massive difference

 

[tlsambo]

What losses do you assume and what size of cable, albedo, height above ground, mismatch, pollution etc? makes a massive difference

Hi Whlphil
Our "Test roof" is set to the default settings. 4mm cable and 10m run I think. I was under the impression that in PV Sol the height above ground doesn't get taken in to account. If you have evidence to the contrary I'd be keen to hear as I took this from Solar Design Company advice and consequently haven't tested that my self.

 

[whlphil]

Hi Whlphil
Our "Test roof" is set to the default settings. 4mm cable and 10m run I think. I was under the impression that in PV Sol the height above ground doesn't get taken in to account. If you have evidence to the contrary I'd be keen to hear as I took this from Solar Design Company advice and consequently haven't tested that my self.

Click on the losses tab when on the array design page you can alter all the parameters I mentioned above, this is typically the reason why people see systems over perform against PVSOL predictions as they just take the defaults. SDC are OK but they dont know everything, Ive been on one of their courses and wasnt very impressed. Chris is a nice guy and very knowledgeable but he's also very busy and cant always deal with all the queries.

 

[tlsambo]

Click on the losses tab when on the array design page you can alter all the parameters I mentioned above, this is typically the reason why people see systems over perform against PVSOL predictions as they just take the defaults. SDC are OK but they dont know everything, Ive been on one of their courses and wasnt very impressed. Chris is a nice guy and very knowledgeable but he's also very busy and cant always deal with all the queries.

sorry, I didn't explain very well. I know where the settings are etc, it's just that our test roof uses the defaults.

Interesting to hear about your feedback regarding the course. I opted not to go on them, just pestered SDC a lot on the phone when we first got the software. I'm just reading Chris's book on solar thermal too and I've met him a few times as well. Don't suppose you have any experience of T-Sol?

Also, have you used the "appliance" feature much? We haven't yet but I'm sure that as this market moves from an "investors" market to a "savings on your bill" we'll be using that a lot more.

 

[whlphil]

sorry, I didn't explain very well. I know where the settings are etc, it's just that our test roof uses the defaults.

Interesting to hear about your feedback regarding the course. I opted not to go on them, just pestered SDC a lot on the phone when we first got the software. I'm just reading Chris's book on solar thermal too and I've met him a few times as well. Don't suppose you have any experience of T-Sol?

Also, have you used the "appliance" feature much? We haven't yet but I'm sure that as this market moves from an "investors" market to a "savings on your bill" we'll be using that a lot more.

No T Sol experience but just about to look at T Sol does it do Biomass boiler designs?

Havent used appliance as nearly all our projects are industrial so tend to use half hour meter data or put in logging first, one of our guys has experience on it and it seems to work fairly well.

I'm not convinced of the financial structure behind PV SOL's accounting (did get the German accounting document that was the principal behind the software but my Germans not good enough!) so we use the outputs into our own spreadsheet, we always use the self use though as its critical for showing the proper returns for the investors, also all our returns are Real Returns not IRR's and include monitoring and maintenance including inverter replacement over life of system.

 

[steve Leese]

if your strugling with documents in different languages just put them in to google translator ,it`s a great tool and its free, we have used it a few times when inverters have the wrong books in them.

 

[whlphil]

Thanks Steve yeah we use it too it's a great tool, also end endless source of fun in the office with the amusing translation it often does!

It was mainly the German accounting standards that form the basis of the way the payback and IRR / ROI are calculated and wether they conform to UK accounting standards, not a problem If your putting your pitch to a homeowner but crucial if your presenting to a bank or a developer. It worked out easier to use our own spreadsheet than get the due diligence done on PVSOL

 

[steve Leese]

I use the translator to put things in to welsh,most of the time it's fine but sometimes it throws a wobbler which makes are welsh director fall around in hysterics

 

[Chris Nunn]

When using PV*SOL to run an economic efficiency calculation, you can pull out all the raw data you want for your own calculations in a spreadsheet. In most cases the yield (IRR or Internal Rate of Return) calculated by PV*SOL provides a robust figure based on the open standard VDI 6025 which is recognised by many banks and financial institutions. Worth noting that Excel spreadsheets (i.e. USA) calculate IRR slightly differently.

Once you have set the UK default figures in PV*SOL, the economic analysis is very straightforward to use. If anyone needs some advice on this then PM me. If you are a customer of ours, we can send you an example PV*SOL project file to import in your own program which will illustrate example UK defaults.