Just passed four years of collecting solar energy on the roof of our condo.  23.3 Megawatt hours – which they say is the equivalent of 422 trees, running a refrigerator for 14.2 years, saving 13.7 barrels of oil or running a light bulb for 205 years.  I just like not paying for electricity, although I still have to pay for a base charge.  However the amount of power that I sell back to the power company pays for 7 months base fees.

I use Enphase micro inverters which allows me to track thru their Enlighten online tracking system.  There are several advantages to using micro inverters besides seeing the hourly or lifetime statistics for each of your panels.  You can tell if one panel isn’t performing as well as another and if your array is partially shadowed it only affects that panel.  As you can see below I’m having concerns about a panel on the lower left row. Which has only come to my attention in the last month of statistics. (they are warranted so I’ve contacted the distributor).

I can also look at the hourly production for the lifetime of the array or the yearly by month. Below is a chart that tells me the best month was May of 2012 and that 2015 is shaping up to be the worst years total production to date.

Months chart for four years solar on condo

You tend to watch the stats and meter run backward in the first few months after installation but neglect to pay attention after the novelty wears off.  I like checking our solar gain and production from afar when we can’t directly experience Durango’s sun. They even have an app for your mobile device so you can see the hourly gains on any date.

Of course with the proliferation of Smart Meters and a progressive Utility company you can now see your daily usage online as well.  The chart on the right is our usage from the power company’s online app. Those days below the line are us selling back power and when it’s above the line we are buying power from the utility provider.  Black line is the daily temperature graph.