As far as I can tell, the solstice happened about an hour ago - placing it on either Thursday the 21st or Friday the 22nd depending upon your time zone.  These short days are pretty unpleasant, and I always look forward to lengthening days this time of year.  So the solstice is both a symbol of gloom, and a symbol of hope that it will all look brighter from here on.

Fitting with the gloom theme, the shortest day of the year was a cloudy, then drizzly, then outright gray and rainy day here in Auburn.  That adds up to the perfect opportunity to see what the bottom end of my solar panels performance is!  So as it grew dark I checked and found that in the worst imaginable conditions, I only generated 1.546 kWh - a far cry from our 40kWh average daily consumption, and probably just enough to power my laptop and monitor during the workday.  Depressing!

But true to the theme of hope, I updated my solar cost savings spreadsheet found that despite the lack of substantial solar output in these horrible conditions, during the first four months of operation I have still saved just shy of $1000.  Right on plan!  Even if electricity prices stay constant, inflation drops miraculously to zero, and for some reason the expected tax breaks don’t materialize, I’ll still break even in about 14 years; averaging about a 7% annual return on my investment.  I’m willing to accept that as the worst possible case!

By the spring solstice, I’m expecting much better news - the calculation (not just the forecast) of the value of this year’s tax breaks, longer and sunnier days, and probably some unavoidable electricity rate increases.  All adding up to a payback of under 10 years.  At least, that’s my solstice hope!