April's generation statistics

Here's the graph for April's generation from our array of solar panels. This is for our 2kW 8 panel solar array (Panasonic HIT panels), mounted on our south-facing roof at approximately 35-40° angle from the horizontal.

The purple line is April, and I've included March (the green line) by way of comparison.  April has again outperformed the forecast.  The forecast amount for April was 177.07kWh, for an average of 5.90kWh per day.

The actual total for April was 223.90kWh, a 46.83kWh excess (26.45% more than predicted), for an actual daily average of 7.46kWh.  Again, another record generation day this month - the 18th April saw a total for the day of 13.2kWh.  (According to http://www.timeanddate.com/worldclock/astronomy.html?n=1331&month=4&year=2014&obj=sun&afl=-11&day=1 there were 14.25 hours of sunlight on this day, giving an average sun strength of 0.926kWh per hour of daylight.)


Here's the yearly forecast chart:

For the year so far (September - April), the panels have exceeded the predicted generation amount by 61.94kWh.

Here is the yearly sun strength graph:

April achieved an average sun strength of 0.57kWh/hr (or 0.57kW as it should be written). Now the shape of the curve from March to April is more apparent - it seems debatable whether May is going to exceed an average 0.6kWh per hour of daylight.

May's current generation prediction is 228.85kWh for the month. There are 465 hours of daylight in May according to the met office, and using April's sun strength value of 0.57kW, my new prediction for May is 465hrs x 0.6kW = 265kWh, an excess of 36.15kWh.  Let's see how close I am next month!