How much electricity will my solar panels generate?

[maxime.corbeau]

Hi everyone,




Is it possible to get an estimate on how much electricity a solar panel is going to generate throughout a year if I have the following information:


-basic product description: dimensions (e.g. 55x25 inches) and power (e.g. 100W), which is how solar panels are advertised on Amazon for instance.
-basic climate data: average sunshine hours (e.g. let's say I live in London and I wikipedia data: /wiki/London#collapsibleTable0)




If not, what kind of data am I missing (based on what I already have)?


Thanks.

 

[sparkless]

its not that simple, you will need to design a system

Try this website

w-w-w dot sunnydesignweb dot com/sdweb/SunnyDesign/Home

 

[maxime.corbeau]

Thanks for the link, but isn't there a simpler way to proceed? Can't I get an estimate (with something like 10% margin) with a manual calculation based on some sensible assumptions?

 

[sparkless]

think about what your asking



a standard 100w panel will generate a completely different output if you face it north in Scotland or you live in Morocco and faced it south.

the 100w panel would still be a 100w panel, but, the output would be completely different

 

[maxime.corbeau]

I know, that is why I provided a link to Wikipedia showing climate data for London which gives us the average temperature and number of sunshine hours per month throughout the year. Wouldn't I be able to make the calculation with that?

 

[sparkless]

it took me a lot of college to learn how to design solar installs and I still use software.

every roof and every system is different

 

[mdovey]

You could try using this site

PV potential estimation utility

You will need to enter location (on the map), data source (Climate SAF is a little more accurate, classic is more conservative), estimated losses (which depend on system, but you could enter 0% for the theoretical max), azimuth (i.e. deviation from due south which the panel is facing - again enter 0 for the theoretical maximum under ideal siting condition), and angle of the panels (again 35 is a good angle to get a ball park figure if the exact angle is unknown)

Matthew

 

[sparkless]

that is a good link, but as I said you have to use software to get a return estimate. there isn't a 10% rule

 

[mdovey]

I'm assuming that the OP only needs a rough and ready (back of envelope) ball park estimate of generation, rather than the level of detail needed for an installation quotation (the fact that it is a 0.1kW system suggest that this is not a install intended for FIT returns, for example).

 

[maxime.corbeau]

Thanks for the link Matthew, that's already much simpler.

 

[sparks0755]

to calculate solar output of panels you need to total up number of panels x watt output of 1, then direction of array which will affect production, then as a ball park to calculate amount of solar irradiation use the SAP calculation for orentation, taking into account shading, and angle on roof, this will give a good idea of annual output. If you need the formula's let me know