How Much Energy Does a 100 Watt Solar Panel Produce?


I tested a 100 watt solar panel over the course of a week (well…10 days, actually) to shed insight on how much energy 100W solar …

Date: August 24, 2023

44 thoughts on “How Much Energy Does a 100 Watt Solar Panel Produce?

  1. your power output is closely matching your hours of usable sunshine. Great validations of on already known number. It would have been more interesting if you were to compare a couple of different brands of panels, but overall, well done.

  2. I have 720 watts of solar on my van using 4 matching panels and I average around 450-500 watts input at any given time on a decent day. I was expecting a bit more but they are flat mounted with no tilt mechanism, which I may add in the future.

  3. I have 6 100w harbor freight panels goining through a vevor grid tie inverter and kill a watt meter maximum watts 440 producing 2.2 kwh per day . Rainy day production drops to 250 watts per day..

  4. nice vlog straight forward unlike other videos 12 mins or more do the same hahaha.. save my time.. thank you new subscriber from Philippines mabuhay! mamatay!

  5. Victoria Australia. Four years ago I installed a 3.75 kW = 14 Panels at 250 Watt each. Worked out the math in advance it should pay itself off in 3-5 years. If it did I would upgrade. It did in 4 years or less so that's the sell on me to upgrade. I now have 24 panels diverged facing East, North and west. It works very impressive when its sunny in summer but! I now have live monitoring with this upgrade with battery system. Its shocking to see how much the power drops as soon as a cloud passes over. Then we have had mostly cloud and rain through this last winter the system is making up for losses of sunlight. Its like it produces near nothing under heavy cloud weather its such a shame really. My new 12 panels are 450 watt each. Its auto calculations say I'm 25% self efficient at these weather conditions so that's not that bad really. I'm waiting to see how high that gets through the next year etc,

  6. I have 10 solar panels here in London facing south 275 each 2750 watts on a cloudy day August summer 0dc as soon as the sun breaks out of cloud 2.700 DC v goes up and down quite A not i have not try it yet when the sun out.

  7. You can lose ~20% efficiency if the panel is hot. 90 degree day ambient likely means well over 100 degrees on the surface of the panel itself. This is just the nature of transporting electricity and more or less applies in all areas of electrical transportation. Electric Companies deal with this issue also where on hot days, their efficiency to transport the power to you is less (which means more power is burned up just trying to get it to you in the heat).

    Panels are rated for 77F basically always. Industry Standard. If the panel says it's 100 watts, it means it's a 100 watt panel in 77F direct high noon kind of sun light.

    Shade, Clouds, debris, bird poop, etc can all inhibit the power generated from a panel noticeably. Really dark clouds, like the nastiest of storms is trying to roll in on you, can take power production down to 5% if you're lucky. Full cloudy day where the clouds are whiter, thinner and you can still kinda see your own shadow, power can vary around 20 to 50% in my experience.

    DC voltage pushed from a solar panel will also lose voltage across the distance of your wire. If you're running a 30 meter wire vs a 100 meter wire, you will lose more voltage on the 100 meter run than the 30meter run. Wire gauge can also affect losses. Using a thicker wire will lose less voltage across larger distances. Plenty of resources online to help figure this, but please do not get trapped on using a resource that's designed very specifically for boating. I see charts in solar communities all the time and people saying which wire gauge to run and different things and then they link a chart as there supporting evidence and you can clearly see on the bottom it says something about "the chart may not cover all unique situations on a boat". Those charts are very specifically for 12/24v systems only. The voltage tolerances can be critical in boating due to how it might be your life out on the water or due to the amp draw that can be happening at those low voltages to get big watts out of the system depending on high lumen light use, stereo, or other equipment and those charts are designed to get the most power across the boat with minimal losses per an industry standard. You can reference that chart but it's pretty pointless to do so if you're running a 100v solar array, as an example. You can move a LOT more power at 100v than at 12v a lot more efficiently, a lot less heat, a lot thinner wire, etc.

    Volts * Amps = Watts. Volts * Amphours = Watthours. Watts is an instantaneous measure of power. Watthours is a measure of power across time. A 60 watt light bulb uses 60 watts. If the light was left on for an hour, it did not use 60 watts, but rather it used 60watthours. If the same light was left on for 10hours, the light used 600watthours. Lots of people mess this up when communicating or trouble shooting or any number of things, and it can sometimes make it difficult to help because they aren't communicating effectively. If you buy an all-in-one system (Bluetti, Echoflow, etc) and you see two different ratings on it like 2,200 watts and 2kwhs, they are not interchangeable, and they do not mean the same thing. Most likely the 2,200 watts I exemplified is in referenced to the inverter's capability. the 2,200 watt rating is telling you that the inverter can deal with you pulling 2,200 watts out of it. The 2kwh rating, which may also read as 2,000wh instead (it's the same exact thing: 2,000wh = 2kwh) is probably telling you how much power the battery can store. Those are two very different characteristics. You could have a 200wh battery and a 600watt inverter in an all-in-one product making these "solar generators", as they are often marketed, and the product page might not be super clear about which characteristic is for which part… but if you see the "h" for hours, that is telling you there's a time component to that rating. So if it says 200wh and 600watts and you can't figure out which is which or what it's trying to tell you or how it can be both… the 200wh (watts across time) is almost certainly the battery and the 600 watts (instantaneous) is almost certainly the inverter capability.

    Colder temperatures will increase the voltage produced by the panel. If your solar charge controller is rated for 145v and you purchase panels to get you to a 140v VOC, you're risking over volting your charge controller in the Winter. Obviously this scales with the temperature, which means it will depend where you live. Increasingly colder temps can mean increasingly higher volts. If you see -30F temps, you probably don't want to push more than maybe 110v VOC on a 145v charge controller.

    My experience in northern latitudes of the states is that a 1500 watt array of Renogy 100 watt panels will generate around 9.5kwh in a day as a best case scenario. I can see this fairly easily as I use a Victron charge controller and it logs power production per day with a 30 day history.

    In addition to the 20% hit to your power generation from the panels because of heat, you should also expect that when it comes time to converting that DC power you've stored up in some kind of battery to Alternating Current, you will have inverter efficiencies to deal with also. A lot of inverters will not have more than maybe 92% efficiency across varying loads averaged. The simple math, I usually just subtract 10% off from whatever power you generate, because you'll definitely lose something in that ball park converting it from DC to AC. So if a 100 watt panel makes 80 watts on a really hot day, you'll get maybe 72 usable watts out of it once you've run it through an inverter.

    I know some of this stuff sounds like it really sucks or it's a scam or whatever people want to say or think once they realize some of this stuff, but like I said… even your electric company has to deal with a lot of this same type of stuff. It's not free to move power around, there's losses. And those losses are bigger the hotter the day it is.

    Self Researched, Self Setup, 2700 watts total in panels, 22kwh total of battery, did not go to school for this stuff, just played with electricity taking things apart since I was a kid and got into this stuff on my own, originally out of curiosity, and then later to see what I could make of it all.

    I probably could've easily tripled my text trying to explain stuff about solar. Series, Parallel, startup resistors, dc to dc converters, soft-starters, pure-sine vs modified sine inverters, transfer switches, etc, etc, etc.

  8. I'm getting 700.9 watts out of the twelve panels that are in the Sun 🌞. The smoke from Canada and dust from the Sahara is cutting down power. I have four other panels but the Sun isn't on them yet. All of mine are 100 watts panels. After the batteries get charged I'll run the window air conditioner for awhile.

  9. I’ve got 4-320 watt and 3-315 watt panels charging 6-6volt AGM 460 batteries and when I have full sun my batteries are fully charged in 2.5 hours. Winter here with less sun it takes much longer.

  10. this is a great video, but how much would you have had to pay that week to get that many kilowatt hours from the electric company. obviously the point of the solar panel is conservation, but i'm curious, how much cash savings could it make

  11. Ideally, you should orient the panels perpendicular to the sun. That is if you put a square on the surface of the panel, it should not make a shadow. Of course the apparent position of the sun will change, and this is what makes sun trackers attractive. For a rough estimate, tilt your panel at the same angle as your latitude. Georgia is located between 34.9° and 30.6° North, so you should have a tilt somewhere between those two values. If you are in Atlanta, in the spirng, for example, use 33° and orient the panel due south. Your current setup appears to have a tilt of about 25° The tilt can also be adjusted for the season: In summer, subtract 12°, ie 21° and in winter, add 12° for a tilt of 45°.

  12. Up front I’m not a electronics geek so I won’t be able to give you exact #’s however we had a 22 panel Panasonic cell system installed last November and have enjoyed 0 $ bills since then and actually had a check for 190$ from El Paso Electric. We live in Southern New Mexico and enjoy 245 average sunny days a year. At the highest out put I’ve seen is about 7 Kwh. Right now on the sunniest of days the highest out put will be in the 5-5 Kwh because the sun angle is still high. It has been hot here and we have two AC units that are well tuned and we keep the house at 77 24/7. Do I think the cost of the system was to much? No, and the reasoning is we reduced our carbon footprint . We have battery backup for those odd times when the power is off. I like the part where I don’t pay a bill.

  13. An 8,000 BTU 1-rm AC unit (LG 8,000 BTU Window Air Conditioner, Cools 350 Sq.Ft., Amazon) draws 2,340+ Watts. Your solar panel, on its best day average, will let you run the AC for 12 minutes.
    (Hint: using how many times you can recharge an iPhone is meaningless – using machines like AC units, microwave ovens, electric ovens, etc., is easier for most people to comprehend.)

  14. Yes, it was definitely that 1 or 2 blades of grass that were denying the crucial photons from collapsing into the critical section photoelectric array and thereby preventing the panel from reaching 100W.

  15. Simpel berekend is.
    5 uur max zon x 100watt = 500Wh per dag.
    Dan is de vraag parallel of serieschakeling.

    Bezit je serie dan kan je meer opbrengen over de dag .

    Het is dus beter 2x50watt dan 1x100watt
    Dat heeft met de mppt tracker te maken en de accu die je gebruikt.

    12 volt accu werk het beste met serie omdat je voor of na die 5 uur max zon . Nog steeds een hogere voltage bezit .

    Een mppt tracker laad een 12volt accu op met 10volt zonnepanelen.
    Een 100watt singel aansluiting is max 22 volt bij die 5 uur zon.
    Een serie zonnepanelen bezitten dus al 44volt op die max 5 uur zon.
    Maar voor die 5 uur zon kan ze gezamelijk dus al 22 volt leveren .

    Dus beste in de winter en eigenlijk altijd zo lang de zonnepanelen niet in de schaduw vallen
    Altijd voor serie gaan dan parallel schakeling.

    Aangezien ik woon op een slecht gebied waar veel regen en weinig licht .
    Staat er bij mij 3×100 watt op serie aangesloten op een 12volt lipo4 accu .
    Dus 66 volt panelen op een 12 volt accu.
    De mppt tracker zal alles om zetten naar de accu .

    Een pwm lader is waardeloos en alleen zinvol als je goed koop een druppel lader zoekt voor onderhoud accu met 1 zonnepaneel.

  16. Was looking to get solar panels, but for what they said I'd need, I'd be paying 350 a month for 20 years to pay for it. But after 20 years, id paying nothing.
    But seeing as how i average less than that a month on electric bill and have a car payment, just wasn't worth it.

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