Worst Case Scenario

January 29, 2017, was cold, cloudy, and rainy, a worse case scenario for our photovoltaic system.  I stood the chill as long as I could, but finally gave in and turned on my electric heat.  Because of the clouds, our solar panels only generated 1.9 KWH of energy while the heat used over 30 KWH.  The percentage from solar shown in the chart is the result. The chart below shows a very atypical day where all of our energy came from the grid and none from our solar panels.

The chart below shows the last ten days of percentage from solar. We were doing quite well actually until the cold front came down and stalled over us.

A Productive Winter Day

Almost a perfect day for solar yesterday. A/C was off most of the day. Ran it briefly during the night to take the humidity down a notch for sleeping. These are still the shortest days of the year.  Firstly, you see my daily percentage meter for yesterday, followed by my hourly consumption chart.   At the bottom of this post,  is the time-lapse video for the daylight hours yesterday.  You can see that the day was not unusually clear.  The temperatures were mild so the A/C was off for most of the day.  I turned it on briefly in the evening to drop the humidity, you can see that in the hourly chart by the noticeable increase in grid consumption around 11 pm.   My irrigation system also ran in the early hours of the morning.  Notice in the time-lapse,, that the sun is still very low on the horizon and is hardly visible in the video.

2016 Year End Analysis

Here’s the histogram for last year’s daily percentage electricity from our solar panels. It gives a good overall picture of the characteristics of our system.  The year started with unusually high consumption for a variety of reasons.  Nevertheless, you can see that we had more days above 50 percent than below.  With more increases in efficiency, I should be able to shift that peak some more to the right. You can mouse over the bars to display individual day values.

Rainy Season

We are well into the rainy season now so the clouds have impacted our electrical generation from our solar panels. Back in the spring with cooler temperatures and clear skies we were generating one hundred percent of our energy and more. Now we are consistently down in the forty to fifty percent range. That’s running the air conditioning pretty much around the clock.

Clouds, Sprinklers, and AC


A cloudy day, no raiScreenshot 2016-03-13 07.14.14n, and higher temperatures impacted our production yesterday.  Our yard was showing signs of stress due to no rain in a while so we ran the sprinkler system in the early morning hours.  It also got rather warm so we ran the air conditioning for a short time in the evening.  Both of these events show as indicated on our consumption from the grid.  In spite of using those high demand devices and the limiting clouds, the percentage of our energy from our solar panels was pretty respectable. Yesterday was an ideal day for isolating the consumption of these systems.

Screenshot 2016-03-13 07.56.23