First Year of Solar

11 x 230W Siliken Panels, Enphase Microinverters

We’re at the 1-year anniversary of throwing the big red switch (yes, there really is a red switch!) on the 2.53kW solar PV installation on our home.(Incidentally, our array shares its birthday with Christof’s array over at in Colorado).

Overall, it’s been fantastic.  There has been no maintenance (unless you count a little snow removal) and no problems whatsoever.  The panels just sit up there and make electricity every day – sometimes more, sometimes less, but the array performance has met our expectations.  (The PVWatts website estimated 3448 kWh/year, and we are reasonably close to that.  I don’t think the default PVWatts derate coefficient factors in snow cover!)

As of this writing, we’ve:

  • Produced 3164 kWh of electricity
  • Exported 1969 kWh to the grid
  • Consumed 3406 kWh from the grid

So that means our household has used (3164-1969+3406) = 4601kWh in the past year, and we’ve made 3164/4601 = 69% of the electricity we’ve used.  We’ve had to purchase the remaining 1437kWh, or average 120kWh/month, or about $12/month for average net electricity costs.

People always want to know about payback; 3164kWh is worth about $316 today, and energy prices are sure to go up.  Even if they don’t, we’d be looking at  about a 16 year simple payback for our out-of-pocket costs for the installation.

Having solar on the house has also increased my desire to push my consumption down – it’s always fun to get a month where you make more than you use – and that’s what has helped motivate us to get down to an average of about 380kWh/month, less than half the average for Minnesota residences.

So – one year down, and many more to go!  You can see what the array is doing at any given time by looking at the widget on this blog, or by going to the Enphase Enlighten monitoring site.

Here’s to solar in MN!

6 thoughts on “First Year of Solar

  1. It sure looks like you need a backyard shade structure to me. The PV panels with the translucent backsheet would give a nice “dappled forest shadows” effect. Or if that doesn’t fly, how about getting crafty and building some really nice window shades that (happen) to integrate solar panels in the design? Only 31% to go. Congrats!

      • Window shade joking aside, some fixed window awnings with integrated PV might actually make sense. It looks like you have the vertical space available above the windows for a decent snow-shedding pitch, and it would also make your house more comfortable in the summer. In this case you might want to go with opaque backsheets, which would be good, since it would allow many more size options. If you fabbed them as units on the ground, and hoisted them in place when ready, the labor might not be too bad either. Note that you can also buy pre-fab mounting kits of this sort if you just want to get the job done and don’t want to go the full custom route…

  2. Congrats! Proud to share the same solar “birthday” as the Sandeen family!

    How much do you think having microinverters helped you in terms of the whole snow sweeping/melting equation?

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