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 http://www.solarchargeddriving.com 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!