The University of Sheffield
Sheffield Solar Farm
Generation for jan2012
User: guava090
Date: 31/01/2012 16:45
Views: 2090
Rating: 0

Hi everyone,

Guava090.Which is a 4kwh system, produced 199kwh this month.


Highest generation for a individual panel was 13.07kwh.

The lowest (which has partial shading late afternoon from a chimney stack was 11.20kwh.

Highest generation day was 15.04kwh.

Lowest was .872w

Location North Hampshire.

Re: Generation for jan2012
User: muymalestado
Date: 31/01/2012 19:19
Views: 2
Rating: 0

Northern Scotland; 2nd full operational month

3.9kW (16 x 4kW REC panels, Kaco 4400 inverter)

Export meter advanced 44kWh in January (18kWh in December)

Highlight was 2 days collecting 3kWh - just wait till summer!

Re: Generation for jan2012
User: Steve Rogers
Date: 09/02/2012 16:35
Views: 0
Rating: 0

You've made me feel better.  I was getting very depressed about my system (3.96 kWp) which only generated 62 kWh in January  and 46 kWh in December.  These are about 1/2 the predicted figures from a PVGIS calculation.  We seem to get orographic cloud forming on the North York Moors escarpment which limits our sunshine hours.  Funny how you get to be obsessive about the weather!

As you say, roll on Summer ...


Re: Generation for jan2012
User: dwilliams
Date: 31/01/2012 19:36
Views: 16
Rating: 0

Hello everyone, here is another report from down south ...

Cedars PV (URN 130) Uckfield, East Sussex. A very variable month alternating between several bright sunny days and then several persistent thick cloudy days. Best day was 27/1 @ 10.4 kWh, worst day was 18/1 @ 0.093 kWh. Overall total for month 126 kWh. (PVGIS estimate for here = 94 kWh) David

Re: Generation for jan2012
User: kwakefield
Date: 01/02/2012 08:57
Views: 20
Rating: 0

Here is my result for Jan from North West Cheshire and a 4KWp system.

Total month 149.1 v 136 PVGIS so I have got to be pleased.

This normalises to 37.3KWh/KWp to allow comparison with other sized systems.

Guava . You seem to have the best output in the UK. I am looking forward to seeing the full data list. Anyone looking to install now should be looking at your equipment.

muymalestado. Yes it will be very interesting to see your data when you have 20hrs a day of sunlight in summer. What you lose in winter you should more than gain back in summer.

Cedars. What size system? That is why it is best to quote KWh/KWp then you do not need to know the system size except for added interest.

Your PVGIS seems low compared to your actual. For Sussex I am sure it should be higher than my 136 in Cheshire.

Seems a good month for all anyway. Cool


Re: Generation for jan2012
User: dwilliams
Date: 01/02/2012 09:22
Views: 17
Rating: 0
Hi Ken, as I am replying on my phone I will keep this short and explain more about my PVGIS comment later. However, I admit I continue to be puzzled about how I get the figure in kWh/kWp that makes comparison easier. From my MCS certificate my system has a Declared Net Capacity (kW) = 3.0. If you can enlighten me it would be much appreciated. David (Cedars PV, URN 130)
Re: Generation for jan2012
User: Brommers
Date: 01/02/2012 09:38
Views: 133
Rating: 0

Hi All,

My system generated 110Kw during January. It is a 3.78Kw system (18 x 210 Upsolar panels & PowerOne Aurora inververter) facing pretty much due south in Western Anglesey, North Wales. 

These figures work out to 29.1 Kwh/Kwp (if thats wrong, please let me know!)

The pvgis figure for my system/location is 108Kw so right in line with my actual figure.


Re: Generation for jan2012
User: Ladysmeader
Date: 02/02/2012 17:05
Views: 73
Rating: 0

Our system achieved 140KWh in January versus a PVGIS estimate of 124KWh. Thats 35.4 KWh/KWp and slightly lower (by 7KWh) than January 2011,Frown but I'm really happy really Smile


3.96KWp 22 X 180W Romag SMT6(48)P Poly panels

Fronius IG40 Inverter  Facing due south, no shading issues

Location: Mid Devon

Re: Generation for jan2012
User: dwilliams
Date: 03/02/2012 11:20
Views: 2
Rating: 0

Ken, having looked at the "normalised" kWh/kWp figures quoted by some others I now realise it's a simple calculation of Net Declared Capacity divided by the total yield generated for the month ... Doh!  So, for Cedars PV it's 126/3 = 42.

You also made an observation about my PVGIS comparison I quoted and how it seems low compared to yours in Cheshire.  Well I cannot guarantee I have it right but if I explain how I arrived at it then people can put me right. 

On my MCS certificate is an Estimated Annual Generation figure of 2575 but scouring my paperwork I could find nothing to help me understand how the installing company arrived at that figure.  Having just installed a Sunny WebBox and made my installation public on the Sunny Portal I looked at other systems where they had activated the Annual Comparison page and noticed that someone had used a factor of 858.  I realised that 858 x the Declared Capacity of 3 = 2574 (close enough).  Now when you enter this factor into the Sunny Portal it calculates a monthly distribution which is what I (rightly or wrongly) quoted as my PVGIS for January.  I did a bit more digging in Google to discover that the factor of 858 comes from the SAP2009 way of working out how much a 1kW system will generate in reality after losses etc.  However, I learned from the article that SAP2009 takes no account of the geographic location of the installation and is based on a system installed from Coventry northwards to Scotland.  It went on to explain that PVGIS adds a geographic element.  I came across a map that colour banded the UK with differing factors and noted that for Uckfield it is more like 882.  Updating the Sunny Portal with that factor resulted in the monthly distribution I quoted.

If you have a look at my page for Cedars PV (URN 130) in the Gallery I have added a link to my public Sunny Portal pages.  Go to the Annual Comparison link on the left and you will see where I get my figures from.  I am happy to admit I still have a lot to learn about PV and that's why I find this website and forum so interesting.  David  

Re: Generation for jan2012
User: kwakefield
Date: 03/02/2012 12:26
Views: 5
Rating: 0


If you go to the PVGIS web site you can generate your own data specifically for your location. You will find your way around the site OK

Powered by Xoolon
© 2011-2014 The University of Sheffield. Visit the Sheffield Solar Farm homepage.