Conceptually solar energy is straight-forward.  The sun shines and power is produced.  Solar power production has much more variability.  This chart reflects 30 days of solar power production recorded every 5 minutes each day.  The data was collected each day in June 2024.

Each daily power production is represented by different shades of gray lines.  One striking feature is the number of near vertical ups and downs.  These are caused by clouds.  Rainy days do not produce a lot of power.

The darkest line in the chart is monthly average solar output in 5-minute intervals.  This 30-day average line peaks at about 5,000 watts, or 5 kilowatts.  The system has nearly 7,000 watts capacity.  But the 30-day average is about 2,000 watts below capacity.

There are a few days where the sun shone sufficiently well a nice, smooth arc over 6,000 watts was produced. The 30-day average generates more watts each day than the median output would show. The daily low-power output due to clouds is much lower than the near capacity high-output days are above average. There are also a few days when the maximum power output for very rainy days did not even get as high as most of the minimum values. June is when the longest day occurs at the summer solstice, June 20. But in downstate Illinois, that does not translate into maximum solar power production.

This chart spans the course of a 24-hour day.  This illustrates that there are still at least 9 hours each day, after dark, where zero sun is shining.  There are another 3 hours in the morning and 3 hours in the evening when solar energy production is off-peak sunlight.

This is an exciting chart.  Even with all the variation and off-peak performance, it is converting photons that hit the earth into usable power.

When this solar system was installed, there was insufficient historical power consumption data.  The system was installed before it became a full-time residence.  Once if became a full-time residence, household power consumption increased significantly.  This data provides the foundation for building a home energy model from which additional energy production technologies can be added.  An annual baseline of household power consumption now exists from which to work.  The fourteen months of solar power production has yielded 120,000 data points (12 times an hour x 24 hours/day x 30 days/month x 14 months).

The data nerds at Biomass Rules are having a field day!