Sunday, January 18, 2015
My head is spinning with Excel charts and graphs, numbers and formulas, oh my! Now that we've had the solar array energized for a couple of months, I thought it would be interesting to see how much energy it's generated and what effect it's had on our electricity bill. WARNING: Excel geekness ahead!
This first chart shows the output from the array. Now late fall\winter is the *worst* time to energize an array, I think, simply because you get a little depressed about the fact that it's not producing at its maximum potential. The sun is getting lower in the sky and the daylight hours are shorter. Here in Missouri, it's often gray and overcast if it's not snowing (although we've had only a few small snows so far this winter).
The red line in the chart below represents the 45 kilowatt hours (kWH) that the solar panels could produce under perfect conditions, which really don't exist.
The green line represents the average daily kWH, which is 14.5 for this time period. See those dips? You can almost chart what the weather was like with this.
This chart is for the entire year because I wanted to demonstrate the effect that the solar panels had on the amount of power we're buying from the utility company. We went "live" at the tail end of October and you can see the big difference there.
See the green arrow? That would be the days that were super cold and we turned on the "chicken furnace" in the coop to keep the girls from turning into ice-chick-les. That thing really sucks the power! (By the way, J. coined the term ice-chick-les, and I laugh every time he says it.)
Oh, and here's another way of looking at the same graph. See the significant drop off in October?
So now for the nitty gritty. Here's what it's done to our monthly electric bill:
We used more power in December because the real cold started and we had our house furnace and chicken furnace on. Still, a 71% is nothing to sneeze at.
I'm now completely obsessed to getting to the big fat zero. Once we get there, we can try to get a negative, which means KCPL is paying us to generate electricity. I can't wait to see what our numbers look like this spring and summer!