Geeky question about solar yield data...
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Temrael
Posts: 394 Forumite
Hi all,
We've had our 4.35 kWp solar PV installed since the end of March and I'm trying to work out how we are doing in terms of meeting our yield projections. Just a bit of fun really, I know the future weather is a bit of an unknown.
I found some historic data from someone local with a similar install to mine and it seems, looking at the last 12 months of data, that they produced around 77% of their total annual yield in the two "summer" quarters of April to June and July to September.
Does that sound about right to you guys, in terms of how much of total annual solar is produced April - Sept? Do you have any historic data to share?
It'd just be cool to very roughly extrapolate from my six months of summer data to guesstimate what a full year might end up at.
Assuming 77% is about right then, doing the maths on my 6 months of summer data (2,907 kWhs), I might reach around 3,775 kWhs on a full year. Which is nice and close to the 3,600 kWhs projection used to sell me the system.
Thanks!
We've had our 4.35 kWp solar PV installed since the end of March and I'm trying to work out how we are doing in terms of meeting our yield projections. Just a bit of fun really, I know the future weather is a bit of an unknown.
I found some historic data from someone local with a similar install to mine and it seems, looking at the last 12 months of data, that they produced around 77% of their total annual yield in the two "summer" quarters of April to June and July to September.
Does that sound about right to you guys, in terms of how much of total annual solar is produced April - Sept? Do you have any historic data to share?
It'd just be cool to very roughly extrapolate from my six months of summer data to guesstimate what a full year might end up at.
Assuming 77% is about right then, doing the maths on my 6 months of summer data (2,907 kWhs), I might reach around 3,775 kWhs on a full year. Which is nice and close to the 3,600 kWhs projection used to sell me the system.
Thanks!
Temrael
Don't use a long word when a diminutive one will suffice.
Don't use a long word when a diminutive one will suffice.
0
Comments
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If you want "geeky" you're in the right place!:DHi all,
We've had our 4.35 kWp solar PV installed since the end of March and I'm trying to work out how we are doing in terms of meeting our yield projections. Just a bit of fun really, I know the future weather is a bit of an unknown.
I found some historic data from someone local with a similar install to mine and it seems, looking at the last 12 months of data, that they produced around 77% of their total annual yield in the two "summer" quarters of April to June and July to September.
Does that sound about right to you guys, in terms of how much of total annual solar is produced April - Sept? Do you have any historic data to share?
It'd just be cool to very roughly extrapolate from my six months of summer data to guesstimate what a full year might end up at.
Assuming 77% is about right then, doing the maths on my 6 months of summer data (2,907 kWhs), I might reach around 3,775 kWhs on a full year. Which is nice and close to the 3,600 kWhs projection used to sell me the system.
Thanks!
These are my figures for the past 5 years;
72%, 75%, 71%, 70%, 72%
Based on my figures you may even better 3775 kWh.:cool: Much of that will depend on the orientation of your system. From now through to spring, East & West facing systems start to struggle a bit because most of the sunshine is around midday.4kWp (black/black) - Sofar Inverter - SSE(141°) - 30° pitch - North LincsInstalled June 2013 - PVGIS = 3400Sofar ME3000SP Inverter & 5 x Pylontech US2000B Plus & 3 x US2000C Batteries - 19.2kWh0 -
Smoething to look at if you're interested.....
If you Google "NASA Insolation Data" you'll find your way to historic insolation data for everywhere on the planet - essentially a measure of how much the sun shines for each day of the year. You can put the data for your area in a spreadsheet and work out, month by month, what percentage of solar energy you're likely to generate for each month of the year. From that you can deduce what you're likely to generate in, say, December based on what you generated in, say, June.
When I did this a couple of years back, my figures were:
Jan 2.25%
Feb 4.31%
Mar 7.22%
Apr 10.99%
May 14.29%
Jun 14.83%
Jul 14.86%
Aug 12.8%
Sep 8.56%
Oct 5.23%
Nov 2.85%
Dec 1.81%
That comes to 76.33% for Apr to Sep so 77% sounds about right.
Having said that, if I look at my actual generation for the last year, I generated a total of 3329.26kWh of which 2368.30kWh (or 71%) was between Apr and Sep.
The difference, as Nick says, is probably accounted for by the orientation of the panels - I can't remeber if or how I accounted for this when I did the theoretical analysis.
Enjoy 0 -
Love it thanks both, just what I was after. Temrael
Don't use a long word when a diminutive one will suffice.0 -
There is also pvgis. As well as orientation angle will also impact relative winter/summer generation, generally sleeper panels better for winter.I think....0
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