Number crunching

My adopted home town is on the high side of these averages, while still maintaining above average rainfalls, which means that if I ever retire I can follow the Amish advice of making sure that my garden is larger than my house.

The payback, of course, is autumnal storms and crushing humidity - but that's life in the deep South....

 

I just ordered an inexpensive DLI meter, or daily light integral meter, from Amazon. It is not made for PV panels but used more for plant propagation and gardening, but it should work for my purpose. With vast local weather differences, the average sunshine data for the state or city from the past records is not very reliable data for my solar analyses. I need actual sunlight measured on my roof.

Today, sun is out, unlike yesterday. For my second day of the PV operation, it has hit 8.8kWh already. And it's not noon yet. If no cloud moves in, the PV should generate close to 20kWh today.

 

Won't a 100w solar panel and an intelligent charge controller give you the same thing, for about the same money??

 

The PV system and app reports the total amount of kWh generated from the panels. I can even look up each individual panel's kW generating in real time. Theoretically, this number should be proportional to the total number of photon hitting the panel. But whole point is to confirm what is being reported by the panel (and app) matches the empirical observation of sunshine based total amount of photons received by the panel per square meter over the course of a day. I just want to confirm the daily mol/m²/d of photon changes closely follows the kWh production from the system over the course of a day.

 

The first full day of solar generation. The sun was out in the morning, but cloud moved in the afternoon and started snowing. Still managed to generate 23.6kWh total. That is less than what we usually use in a single day (our average is 34kWh/day). But 70% coverage on winter day is not bad.

 

You ae correct, sir.
HOWEVER (comma!)
Using a separate PV panel and controller and taking independent samples would yield the same data set at roughly the same price point as the TEMU-meter, allowing for monitoring and analysis of THAT SEPERATE PV panel's performance over time; essentially acting as a data logger independent from the system.
Since humans usually have 10 fingers, the 100w panel also makes for easy math.

AND.....
You would get to harvest the electricity WHILE you were taking your measurements.

 

Can you show me a link to your $47 100w solar panel and an intelligent charge controller? If it has a Bluetooth capability and data logging app for that price, I am going to buy one... More measurements are always better to verify the data.