Hi I have a circular shape 7cm in diameter solar panel rated at 5.5V 80mA = 440mW. My question is how much power would it output on average during the winter when there is about 8 hours of day light? do I need to find out how much lumens there are per day in winter and convert it into Watts, if so could someone please assist me on doing so.
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1\$\begingroup\$ You need to get the amount of sunshine hours per day and work from there. Have a look at this but then do it for your location : weatheronline.co.uk/weather/maps/…. also see photovoltaic-software.com/principle-ressources/… \$\endgroup\$– Solar MikeAug 9, 2019 at 14:33
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\$\begingroup\$ A crude approximation would be to take the panel efficiency as a static value and just recompute for the lower irradiance during winter. Good enough for an approximation? \$\endgroup\$– winnyAug 9, 2019 at 14:35
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\$\begingroup\$ Depending on application (and area of deployment), you may need to allow for extended periods of thick clouds in winter. There is still sunlight when it is cloudy, but less of it. \$\endgroup\$– Martin Bonner supports MonicaAug 9, 2019 at 14:45
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1\$\begingroup\$ Will it get covered by snow? Will it track the sun? if not, what direction will it point?We have some roof panels in Scotland (which is far enough north to get only 8 hours daylight per day), and between snow, cloud, sun angle and short daylight they produce less than 1% nominal during the winter. \$\endgroup\$– Jack BAug 9, 2019 at 15:09
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1\$\begingroup\$ Also, are you asking how much power the panel could produce? or are you asking how much it actually will produce in some particular application? The operating point of your system at any given moment does not only depend on the properties of the panel and the intensity of the light, but also, it depends on characteristics of the load that you connect to the panel. \$\endgroup\$– Solomon SlowAug 9, 2019 at 16:38
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it depends a lot from angle you put the panel relative to Sun's elevation angle. Someone might say or write: "solar panels next to nouthing power in winter beacouse Sun's light comes at a very steep angle", that is not particularly thue, especially if solar panel is aligned perpendicular to incoming light. equasion should be the following: E=CTcos(Sang-PVang)Pnom(1-W), where C is a constant (I beelieve in 1/3 to 1/2 range), T - time (per day) Sun shines on solar panel, Sang - Sun's maximum angle above horizont, PVang - angle beetween vertical line and solar panel's plane, Pnom - rated solar panel power and finally W - amount of time that weather conditions cover the Sun. Equasion gives E - energy anaiable from solar panel in 1 day.