Recent content by dareed1

I use Windows, so I wrote a short description of how to use tesla-solar-download with Windows 11

I use WIndows 11, and the readme.md file is clearly aimed at Linux. And I prefer to not wrestle with GitHub or svn. So I did the following: I went to the link above, clicked on the green Code button, and downloaded the distribution as a ZIP file, and unzipped this into a suitable folder, which...

Yes, that explanation makes good qualititative sense. To check, I used a solar insolation spreadsheet with 5 minute summing intervals and this showed that at 38 degrees latitude south facing panels with 4 degreees of tilt gave about 1% more energy over the day of June 21 than using the 14.5...

Wayne, I'll try again. The optimal tilt angle for solar noon is latitude - declination, as I said. You're quite right that this is also the solar zenith angle: the angle of the panel normal to vertical is equal to the tilt angle of the panel plane to horizontal. Regarding the second point...

Wayne, Solar declination is not the same as elevation. Elevation = 90 + declination - latitude for the northern hemisphere. They're different coordinate systems. I think (hope) what I wrote is correct. But the meaning of your last sentence isn't clear to me, neither the phrase "below the...

This website has a simple and also a more complex equation for solar declination and shows the error by using the simple equation. To get the optimal panel tilt at solar noon, subtract the declination from the solar site's latitude.

PG&E monthly bills could jump for many customers due to new state law They're reporting on a proposal, contrary to the headline and first paragraph.

Perhaps I don't understand your system, but the idea that the CTs should be located at the inverters does not make sense from an electrical or instrumentation point of view. CT stands for Current Transducer, and it measures the electrical current. The current is the same at the GW as it is 800...

We are on TOU-C, for which the difference between peak and off peak is <10% (October through May), so I leave the PW reserve at 90% all of the time in winter. Even if you are on an EV rate plan it may make sense to raise your reserve when the multiday forecast is for stormy weather. BTW, we...

I think you need to identify the nature of your energy flows in order to see if more storage is actually useful. I ran PVWatts on Honolulu and it shows that winter (3 months) generation is about 11% below the yearly average, while summer (4 months) is about 9% higher. The other months are...

My above calculation assumed all of the panels are facing directly south, and that is the very best orientation to get peak power. BTW, for this time of year at 44 degree latitude, the optimal panel inclination would be around 66 degrees. Normally, we describe north as azimuth 0 degrees, so...

I don't suppose that you will want to hear this, but this is much more likely to be incorrectly installed current transducers than actual generation. I ran PVWatts on Rockford Maine, and even with a 45 degree roof pitch with panels oriented exactly south and ground albedo at 0.87 (meaning snow...

As yblaser pointed out earlier, the idea that smaller inverters provide better efficiency at low irradiance is technically probably true, but the effect for modern inverters is negligible. I'm not sure if the start up voltage being 35 volts is meaningful, but Delta claims MPPT operates from 50...

I also couldn't easily get anyone to provide a ManualJ calculation, so I did it myself using the nearly free software from CoolCalc. IIRC, after carrying out the calculation, I paid $10 to allow the calculation to be transferred to a PDF file. When I did this a couple of years ago, the $10...

Just in case it isn't clear, a non-bypassable charge is applied to all electric power supplied by the utility. "Non-bypassable" means that power that you send to the grid is not subtracted. So for example, if you consume 500kW in a month from the grid, and send back at other times during the...