My solar production I have some questions

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Woodsplitter67

Minister of Fire
Jan 19, 2017
3,605
Woolwich nj
I got my system installed. I look at my inverters and its telling me my production. For example in the early AM i my produce 800 watt when the system is first waking up, later in the morning i will produce 3 to 4000 watts the sun comes up more and i produce 7 to 8000 watts. I have arbitrarily checked it and its producing 11,000 watts. My question being how do i figure out from this information how many kilowatt hours am I producing. Just say my goal is aprox 20,0000 kilowatt hours for the year. Am i going to produce this much with these numbers
Thanks for your help
 
Might help using the something like miles instead of watts. The KW reading is your speedometer, its how fast your are going at any given time. kWh is your trip odometer. In the AM the trip odometer is reset to zero and starts counting how many watts/hours you produced. At the end of the day whatever is on your watt hour meter is what you produced.Most inverters have a read out of how many kWh you produced the day before.

Yearly production is going to vary year by year just like the weather does. Some years you will produce more, some less. Various data bases used to calculate solar have long term averaged idea production data collected over a period time. The programs pick the nearest site or sites and assumes your installation will receive similar quantities of sun, clouds and rain over the course of the year. From there they can estimate your production assuming a conversion efficiency between the panels and the utility meter. Most grid ties folks claim the assumed efficiency factor is low.

If you put your system info in PV Watts you can see what it estimates for monthly production but a stretch of odd weather could skew your current results. Note PV Watts doesn't factor in shading so if you have shading you need a different program that factors it in. It may take a year or so to really see how well the system matches up with projected output. Note that new panels have a slightly higher efficiency initially that rapidly drops off, depending on the solar panel company they may just factor that into the efficiency curve so you get just a slight short term amount of overproduction for the first few days/weeks.

What do you have for monitoring?. If you have a nice bell curve on a sunny day and the instantaneous output is about 75 to 80% of the panel rating your system is probably running correctly. If you see big flat spots on the curve and the sun was out then you have problem. By the way if you remember your high school math, if you plot the kW curve out, the total number of kWh produced for the day is the area under the graph.
 
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Might help using the something like miles instead of watts. The KW reading is your speedometer, its how fast your are going at any given time. kWh is your trip odometer. In the AM the trip odometer is reset to zero and starts counting how many watts/hours you produced. At the end of the day whatever is on your watt hour meter is what you produced.Most inverters have a read out of how many kWh you produced the day before.

Yearly production is going to vary year by year just like the weather does. Some years you will produce more, some less. Various data bases used to calculate solar have long term averaged idea production data collected over a period time. The programs pick the nearest site or sites and assumes your installation will receive similar quantities of sun, clouds and rain over the course of the year. From there they can estimate your production assuming a conversion efficiency between the panels and the utility meter. Most grid ties folks claim the assumed efficiency factor is low.

If you put your system info in PV Watts you can see what it estimates for monthly production but a stretch of odd weather could skew your current results. Note PV Watts doesn't factor in shading so if you have shading you need a different program that factors it in. It may take a year or so to really see how well the system matches up with projected output. Note that new panels have a slightly higher efficiency initially that rapidly drops off, depending on the solar panel company they may just factor that into the efficiency curve so you get just a slight short term amount of overproduction for the first few days/weeks.

What do you have for monitoring?. If you have a nice bell curve on a sunny day and the instantaneous output is about 75 to 80% of the panel rating your system is probably running correctly. If you see big flat spots on the curve and the sun was out then you have problem. By the way if you remember your high school math, if you plot the kW curve out, the total number of kWh produced for the day is the area under the graph.

Thanks for the reply and thanks for taking the time. I called my solar guy. They have it monitored and hooked me up with the link and log in so now i can see the production.. its pretry cool..
 
Thanks for the reply and thanks for taking the time. I called my solar guy. They have it monitored and hooked me up with the link and log in so now i can see the production.. its pretry cool..
pics, or it didn't happen :)

upload_2018-10-9_14-9-19.png
as you can see, its been cloudy the last few days :(
 
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Fall tends to be pretty cruel for solar production.
 
I have had my panels for 4 years now, this September was so rainy and cloudy that I only produced about half of what I did the last 3 septembers. October so far has been not been trending much better so far. I have to believe that I am getting the same effect on the seasoning of my wood. Good solar months = good wood drying months and vice versa.
 
With low sun angle and tree shading we get little solar production from now until March. The second array will pickup some on sunny days, but the difference is dramatic from peak summer production.
 
With low sun angle and tree shading we get little solar production from now until March. The second array will pickup some on sunny days, but the difference is dramatic from peak summer production.

So the sun was out for a while today.. there was definitely cloudy times but so far my production was 50kwh and thats not the final total.. so i think that this is good and im happy i think...
 
So the sun was out for a while today.. there was definitely cloudy times but so far my production was 50kwh and thats not the final total.. so i think that this is good and im happy i think...
That's decent and the benefit of a more southerly latitude.
 
That's decent and the benefit of a more southerly latitude.

Im not trying to come off like an A-hole. Your in Washington state and im in new jersey. The difference between us is just slightly over 7 degrees. Dose 7 degrees really make that much of a difference and how is that such a big difference. To me 7 degrees isnt that much of a difference. What am i missing.. again im not starting a fight..
 
Im not trying to come off like an A-hole. Your in Washington state and im in new jersey. The difference between us is just slightly over 7 degrees. Dose 7 degrees really make that much of a difference and how is that such a big difference. To me 7 degrees isnt that much of a difference. What am i missing.. again im not starting a fight..
7 degrees makes a huge difference, especially when you are talking about the orbit of the earth :)

roughly 200 hours of useable sunlight per year difference... (i just picked random addresses with similar solar exposure and size)
upload_2018-10-17_15-18-16.png
 
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Im not trying to come off like an A-hole. Your in Washington state and im in new jersey. The difference between us is just slightly over 7 degrees. Dose 7 degrees really make that much of a difference and how is that such a big difference.

The difference is pretty large. In the Seattle area we are a bit above the latitude of St. John's Newfoundland, which is further north than Quebec City. The sun's angle much lower in winter and this creates issues of shading from trees and hills when shadows become more exaggerated. That's what gets us on our property. If we were on clear south sloping property with no trees than this would not be an issue, but out here we have big trees. There are doug firs that are 150+ ft tall, casting long shadows. And these are the young trees, not old growth.
 
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7 degrees makes a huge difference, especially when you are talking about the orbit of the earth :)

roughly 200 hours of useable sunlight per year difference... (i just picked random addresses with similar solar exposure and size)
View attachment 231118

Really to be honest i didnt think it made that much of a difference.. thanks for posting this.. 200 hours of production is alot. That is roughly 12 hours of sun for 16 days .. so basically I'm getting a half months more worh of solar generation then bgreen..
Thanks for the info guys and helping me understand.. i haven't checked the final total yet but im thinking I did another 50kwh day today
 
You're probably getting a lot more than 200 hrs. Our winter production is poor. Even now our #1 array is shaded and producing poorly until about noon. Wasn't this way when installed but trees keep getting bigger.
 
You're probably getting a lot more than 200 hrs. Our winter production is poor. Even now our #1 array is shaded and producing poorly until about noon. Wasn't this way when installed but trees keep getting bigger.

I also have near by trees and i can see the dilemma of shading as part of my array gets a varrity of shade theough the day
 
I never appreciated a sunny day as much as I do now with the PV system. Cloudy after cloudy day hurts, especially with a new system and hoping it will push out the kWh every day. It's all about the averages: bunches of cloudy days in October-December vs a bunch of sunny days in Jan-Sept. The sunny days win.
 
You guys need to get your panels on PVOutput. I have a consumption meter hooked up to mine so I can see track usage and production very accurately. I also have my inverters internal temperature displayed and my Wunderground weather station data added as well. Its also a great tool to track nearby arrays and compare production.

Another big plus is PVoutput reports data much more accurately in minute intervals. The graphs and data you can look at when hooked up with a consumption meter is nuts. They have daily, monthly and yearly charts and graphs. You can also add your electricity cost and it will roughly calculate your savings.

Here is my site.

https://www.pvoutput.org/intraday.jsp?id=60553&sid=53905

snip_20181019082646.png
 
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You guys need to get your panels on PVOutput. I have a consumption meter hooked up to mine so I can see track usage and production very accurately. I also have my inverters internal temperature displayed and my Wunderground weather station data added as well. Its also a great tool to track nearby arrays and compare production.

Another big plus is PVoutput reports data much more accurately in minute intervals. The graphs and data you can look at when hooked up with a consumption meter is nuts. They have daily, monthly and yearly charts and graphs. You can also add your electricity cost and it will roughly calculate your savings.

Here is my site.

https://www.pvoutput.org/intraday.jsp?id=60553&sid=53905

View attachment 231232

Thanks for posting this. Im gping to loom at this over the winter.. whats the cost for it
 
you added your own usage monitor? any more info on that?