Now that I have your book, and it's awesome, by the way, I probably won't be in the comments with questions as much. I still want to help with the algorithm. I will at least say hello on each video and click like. Lastly, everyone reading this, get the book. You can't beat the price and it's perfectly intuitive. You won't regret it.
I made my own tests. A panel rated by the manufacturer may be 100 watts but that is a lie. They take the short circuit amperage(almost 0 volts) and multiply it by the open circuit voltage with the sun at 90 degrees to the panel; this is about 5 amp short circuit and 20 volts open circuit. As the panel amp load increases the panel voltage drops and a horizontal sunlight produces much less electricity. I use a quality MPP converter that under the best of conditions will deliver about 80 watts per panel. If the battery is discharged or there is a lot of RV load then the power generated reaches a maximum of 80 watts. My RV fridge takes about 11 amps DC at 12.6-14 volts. That is about 120-140 watts. I have 5 solar panels rated 100 watts each and can get under the best of conditions about 400 watts maximum. Ordinarily I can get about 300 watts with good sunlight. In direct sunlight the panels can provide enough power for the fridge and a little extra to recharge the RV battery. Parked at night I can use propane or battery. My truck has a 100 amp alternator which maxes out its v-belt capability and it is from a Ford diesel for low RPM charging; it is on a 460 engine. I have 2 RV batteries with one mounted on the truck frame and that one is usually for the fridge. When I get around to it I will install a low voltage cutoff to the fridge to prevent battery damage. There are many other things I have done to make my camper more useful and reliable. BTW, I have found too many defective LED lights for RV and auto use with their failures often an intermittent short circuit which happens when the LED has been operating for awhile.
Thanks for your comment. The power of a solar panel is determined by multiplying the Vmp and the Imp. Not the Voc and Isc. A solar panel is tested at STC (standard test conditions), this is 1000W/m² at 25°C/77°F. Sunhours is rated at 1000W/m² so we multiply by the sunhours for a given location and time of year. This is very accurate as I have shown in part one of the video. Your reference of good sunlight is not 1000W/m², more like 800W/m² at a higher temperature than STC. That's why you get less power than the solar panel is rated for. If you use sunhours correctly, then the numbers will match the expectation. I felt this was necessary to explain.
My data: 8-year-old fridge in use for a family of 4 averages 45w continuous (observed over about 20 days), which comes to 394kwh/year. Then, my 14.88kw nameplate solar array with 48x 5-year-old panels at 47° tilt (same as my latitude, which is a little more winter-oriented than commercially-installed panels) produces 18.3mwh/year on average. However, that direct panel output - not inverted AC. My whole system achieves about 89% efficiency to turn the solar power into usable AC, so that comes to 1.09mwh usable AC/1kw of panel rating, or 109kwh/100w panel. In other words, in my array (which I admit is slightly more winter-oriented than commercially-installed arrays), it takes 360w worth of nominal panel rating to offset my fridge running at 45w on average. By the way, the PVWatts tool very closely predicted my system's output, so I would definitely recommend it. I would expect it will be on to within 20% or so unless you have some shading issues you don't factor into the calculation.
In cloudy San Francisco, I have a 9.1 kilowatt solar panel system (mounted level on a flat roof) that cost ~$21K after subtracting a 30% tax credit. On a sunny June day, it can produce more than 60 kwh. I estimate that over the year, I will get about 10,000 kwh. Since the electric utility, PGE, charges a whopping $0.50/kwh, the solar panels have an excellent return on investment.
$0.5/kwh is huge! I assume you are using a grid tied string inverter which back feeds the excess power into the grid? Is your feed in tariff 1-1? Would it be interesting for you to add a battery?
I live in the deep south US - 50 miles from the gulf of Mexico - Its very humid in my area - the mioistur defuses the UV light from the sun so it does not strike a solar panel dirctly - I know power generation my grandfather was a early 1900s machanic electrican and some pf my uncles were early radio transmiter engineers - in my case im a third generation machanic electrican - I spent my yrs from the early 70s as a SCR electrician in the offshore oilfields - i understand power production - Were im at solar panels perform very poorly - sense the UV is scatterd by the moisture in the air - if a panel generates 25% rated out put at noon day down here that is concidered good - that would be on a rare low humidity day - Ive worked with panels on unmaned platforms for microwave repeaters offshore - in those cases the panels are 4ft×8ft and are utility grade panels rated at 400 volts 400 watts - In those cases we only need them to generate 80 watts each for about 1 hr a day - of course there might be 12 panels - so there is ample time to recover the lithium sulphurr batterys - What im getting at is if your planning setting up on solar, you need to buy an inexspencive panel and set it up and observe the actual out put in your area - Ive worked with solar panels sence the 1970s - in the south west a utility panel might put out 100% when the humidity is 17% at noon day - then for 4 to 5 hours we have seen chart recorder readings that recorded a 80 to 90% out put for 5 hrs of a day - in my area if we have 10% output at 3 pm that is good not including cloud shadows - for those who have never used solar panels, they dont know these things - Ive worked remote mountain oilfield sights also - at 10000 ft and 5% humidity @ 0° F solar panels might put 100% for a good part of the day - But at 100°.F @35 % humidity at sea level there often not reliable at all - In 2022 we had cloud cover from February till July - So the genrators ran every day on all the uaned platforms to charge the reapeter batterys for 5 months -
Please do a video on how to connect a charger to (4) 12v 100ah batteries wired in series. Do I need two chargers: a 12v charger to charge each battery before I hook them up and a 48v charger once they are wired in series? Also, do I need a balancer? I heard somewhere that if you charge them separately once or twice a year it will keep them balanced. I would like to get your opinion though. Also, how does a balancer affect the lifespan of the batteries?
Thank you for the information. Can you do a video about using a solar power station, such as a Bluetti 200Max and solar panels of around 500 watts? A power station can eliminate the need to purchase everything needed to customize a system as the solar station includes all the electronics in one box. Also, if this system is utilized in an RV, you can keep it as the solar station and solar panels can easily be moved to a new rig. Many thanks.
I have a reliable 3500 w 48v I can only afford 6v deep cycle battery and I have the 8 battery but my inverter is a hybrid inverter and I 3 solar panel 345 w can you help me please I have one refrigerator that’s ?
You are working the wrong way around. First, you need to do a load analysis of your devices. Then, decide how many batteries you need for your preferred days of autonomy. Then, you select a battery size to fit your loads. Then, you calculate the amount of solar power to recharge the battery in one day. Check my video about sizing your solar system for more information.
Unfortunately, a Solar Panel is only 20% efficient, up from 18% a few years ago. I have 4 x 300 W panels. Taking just one 300W panel, at 20% efficiency = 60.12W. Doing the math's. 60.12W x 95% = 57.1W x 97% = 55.38W x 49.84W x 4 Panels =199.38W. 4 x 300W = 1200W. That is the theoretical Wattage according to the attached stickers. The reality is that what I'm getting is (measured), 18V x 2.75A = 49.5W x .95 = 47.025W x .97 =45.614W x .9 = 41.05W. For the 4 panels =164.2W. Using 4 hours as an average = 656.8A/h/day The 2.75A measured with a Clamp meter. The Panels were lying flat. An efficiency of 13.68% at midday. I am on the 26 Parrell South. It is possible to increase the Amperage to 4.5A at midday as when I did the tests. That would still only get me 268.71W. Using 4 hours again as an average = 1074.84A/h/day. an efficiency of 22.4% at midday. That is not the 1200W as indicated on the attached sticker for the 4 Pannels. I do have 4 x 125Ah Batteries to charge.
No such thing as a 100W panel. Comparative tests video'd for UA-cam show a huge output range for various brands. The highest I saw was 90W. 75W is quite common. Rip-off 100W panels (about half size) make as low as 30W. Most of these tests are side by side, so test conditions are consistent. If you ASSUME your panel will output 100W max under ideal conditions you'll likely be disappointed.
Be careful I purchased a fake 100 w panel tested it was equivalent to a 50w panel ..20 watts equates to 1100 milliamps which is 1.1 amp therefore a true 100 watt panel producers 5.5 amp hour
Now that I have your book, and it's awesome, by the way, I probably won't be in the comments with questions as much. I still want to help with the algorithm. I will at least say hello on each video and click like. Lastly, everyone reading this, get the book. You can't beat the price and it's perfectly intuitive. You won't regret it.
Thanks Stephen; I appreciate your kind words. Comments like these keep me going!
@cleversolarpower it's all good brother. You have a heart for people. That resonates with me. Stay blessed.
Where can I get this book?
@@user-dp3pf1jd2k Amazon
@@user-dp3pf1jd2k
on Amazon: cleversolarpower.com/off-grid-solar-power-simplified
It is amazing what one can do with a 100 watt solar panel. Thanks for the video.
I run 6 panels of 230w each and most of the time come home to a full setup of lithium 48v 200a, by my self and 80% off grid 😋
Very informative. Thanks.
You are doing a really good job sir! Keep on going and you will reach 1m subs fast!
Great video! Thanks! We have a bit on solar also
This is surprisingly accurate, my hobby setup calculated out very close with your figures, excellent job.
I made my own tests. A panel rated by the manufacturer may be 100 watts but that is a lie. They take the short circuit amperage(almost 0 volts) and multiply it by the open circuit voltage with the sun at 90 degrees to the panel; this is about 5 amp short circuit and 20 volts open circuit. As the panel amp load increases the panel voltage drops and a horizontal sunlight produces much less electricity. I use a quality MPP converter that under the best of conditions will deliver about 80 watts per panel. If the battery is discharged or there is a lot of RV load then the power generated reaches a maximum of 80 watts. My RV fridge takes about 11 amps DC at 12.6-14 volts. That is about 120-140 watts. I have 5 solar panels rated 100 watts each and can get under the best of conditions about 400 watts maximum. Ordinarily I can get about 300 watts with good sunlight. In direct sunlight the panels can provide enough power for the fridge and a little extra to recharge the RV battery. Parked at night I can use propane or battery. My truck has a 100 amp alternator which maxes out its v-belt capability and it is from a Ford diesel for low RPM charging; it is on a 460 engine. I have 2 RV batteries with one mounted on the truck frame and that one is usually for the fridge. When I get around to it I will install a low voltage cutoff to the fridge to prevent battery damage. There are many other things I have done to make my camper more useful and reliable. BTW, I have found too many defective LED lights for RV and auto use with their failures often an intermittent short circuit which happens when the LED has been operating for awhile.
Thanks for your comment. The power of a solar panel is determined by multiplying the Vmp and the Imp. Not the Voc and Isc. A solar panel is tested at STC (standard test conditions), this is 1000W/m² at 25°C/77°F. Sunhours is rated at 1000W/m² so we multiply by the sunhours for a given location and time of year. This is very accurate as I have shown in part one of the video. Your reference of good sunlight is not 1000W/m², more like 800W/m² at a higher temperature than STC. That's why you get less power than the solar panel is rated for. If you use sunhours correctly, then the numbers will match the expectation. I felt this was necessary to explain.
@@cleversolarpower My tests were real world.
Nice video, thanks :)
My data: 8-year-old fridge in use for a family of 4 averages 45w continuous (observed over about 20 days), which comes to 394kwh/year.
Then, my 14.88kw nameplate solar array with 48x 5-year-old panels at 47° tilt (same as my latitude, which is a little more winter-oriented than commercially-installed panels) produces 18.3mwh/year on average. However, that direct panel output - not inverted AC. My whole system achieves about 89% efficiency to turn the solar power into usable AC, so that comes to 1.09mwh usable AC/1kw of panel rating, or 109kwh/100w panel.
In other words, in my array (which I admit is slightly more winter-oriented than commercially-installed arrays), it takes 360w worth of nominal panel rating to offset my fridge running at 45w on average.
By the way, the PVWatts tool very closely predicted my system's output, so I would definitely recommend it. I would expect it will be on to within 20% or so unless you have some shading issues you don't factor into the calculation.
EXCELLENT
Real world examples are nice.
In cloudy San Francisco, I have a 9.1 kilowatt solar panel system (mounted level on a flat roof) that cost ~$21K after subtracting a 30% tax credit. On a sunny June day, it can produce more than 60 kwh. I estimate that over the year, I will get about 10,000 kwh. Since the electric utility, PGE, charges a whopping $0.50/kwh, the solar panels have an excellent return on investment.
$0.5/kwh is huge! I assume you are using a grid tied string inverter which back feeds the excess power into the grid? Is your feed in tariff 1-1? Would it be interesting for you to add a battery?
Great data presentation !
Thanks!
U r so professional, wish to have the same but for a batteryless system for less maintenance
I made a video for solar without battery
I live in the deep south US - 50 miles from the gulf of Mexico -
Its very humid in my area - the mioistur defuses the UV light from the sun so it does not strike a solar panel dirctly -
I know power generation my grandfather was a early 1900s machanic electrican and some pf my uncles were early radio transmiter engineers - in my case im a third generation machanic electrican -
I spent my yrs from the early 70s as a SCR electrician in the offshore oilfields - i understand power production -
Were im at solar panels perform very poorly - sense the UV is scatterd by the moisture in the air - if a panel generates 25% rated out put at noon day down here that is concidered good - that would be on a rare low humidity day -
Ive worked with panels on unmaned platforms for microwave repeaters offshore - in those cases the panels are 4ft×8ft and are utility grade panels rated at 400 volts 400 watts -
In those cases we only need them to generate 80 watts each for about 1 hr a day - of course there might be 12 panels - so there is ample time to recover the lithium sulphurr batterys -
What im getting at is if your planning setting up on solar, you need to buy an inexspencive panel and set it up and observe the actual out put in your area -
Ive worked with solar panels sence the 1970s - in the south west a utility panel might put out 100% when the humidity is 17% at noon day - then for 4 to 5 hours we have seen chart recorder readings that recorded a 80 to 90% out put for 5 hrs of a day - in my area if we have 10% output at 3 pm that is good not including cloud shadows - for those who have never used solar panels, they dont know these things -
Ive worked remote mountain oilfield sights also - at 10000 ft and 5% humidity @ 0° F solar panels might put 100% for a good part of the day -
But at 100°.F @35 % humidity at sea level there often not reliable at all -
In 2022 we had cloud cover from February till July -
So the genrators ran every day on all the uaned platforms to charge the reapeter batterys for 5 months -
You are good👍🏾❤️
What about Aircon for the Van?
Please do a video on how to connect a charger to (4) 12v 100ah batteries wired in series. Do I need two chargers: a 12v charger to charge each battery before I hook them up and a 48v charger once they are wired in series? Also, do I need a balancer? I heard somewhere that if you charge them separately once or twice a year it will keep them balanced. I would like to get your opinion though. Also, how does a balancer affect the lifespan of the batteries?
Thank you for the information. Can you do a video about using a solar power station, such as a Bluetti 200Max and solar panels of around 500 watts?
A power station can eliminate the need to purchase everything needed to customize a system as the solar station includes all the electronics in one box. Also, if this system is utilized in an RV, you can keep it as the solar station and solar panels can easily be moved to a new rig. Many thanks.
I have a reliable 3500 w 48v I can only afford 6v deep cycle battery and I have the 8 battery but my inverter is a hybrid inverter and I 3 solar panel 345 w can you help me please I have one refrigerator that’s ?
Thanks,
Thanks , I am building motorhome. For
1200 wh solar panel !
How many and amp battery,
I do need?
Thanks
You are working the wrong way around. First, you need to do a load analysis of your devices. Then, decide how many batteries you need for your preferred days of autonomy. Then, you select a battery size to fit your loads. Then, you calculate the amount of solar power to recharge the battery in one day. Check my video about sizing your solar system for more information.
@@cleversolarpower
Million thanks again
A 100 Watt solar module produces approximately 89 Watts of useable powwr in full sunlight.
Please watch the whole video where I explain the definition of sunhours.
Unfortunately, a Solar Panel is only 20% efficient, up from 18% a few years ago. I have 4 x 300 W panels. Taking just one 300W panel, at 20% efficiency = 60.12W. Doing the math's.
60.12W x 95% = 57.1W x 97% = 55.38W x 49.84W x 4 Panels =199.38W. 4 x 300W = 1200W. That is the theoretical Wattage according to the attached stickers.
The reality is that what I'm getting is (measured), 18V x 2.75A = 49.5W x .95 = 47.025W x .97 =45.614W x .9 = 41.05W. For the 4 panels =164.2W. Using 4 hours as an average = 656.8A/h/day
The 2.75A measured with a Clamp meter. The Panels were lying flat. An efficiency of 13.68% at midday.
I am on the 26 Parrell South. It is possible to increase the Amperage to 4.5A at midday as when I did the tests. That would still only get me 268.71W. Using 4 hours again as an average = 1074.84A/h/day. an efficiency of 22.4% at midday.
That is not the 1200W as indicated on the attached sticker for the 4 Pannels. I do have 4 x 125Ah Batteries to charge.
I agree with you in that the manufacturers lie about the actual power output. Lucky to get 50% of power output that reads on the label.
No such thing as a 100W panel. Comparative tests video'd for UA-cam show a huge output range for various brands. The highest I saw was 90W. 75W is quite common. Rip-off 100W panels (about half size) make as low as 30W. Most of these tests are side by side, so test conditions are consistent. If you ASSUME your panel will output 100W max under ideal conditions you'll likely be disappointed.
Did you even watch the video? 😅
Be careful I purchased a fake 100 w panel tested it was equivalent to a 50w panel ..20 watts equates to 1100 milliamps which is 1.1 amp therefore a true 100 watt panel producers 5.5 amp hour