After taking into account all federal and state credits as well as the cost of electricity that I didn't have to pay for, I have officially reached the break-even point of my solar system after 60 MWh of production. Here is the math / details for people considering going solar:
Cost of system (in 2019) - $37,090, consisting of 40 330 watt Panasonic panels with optimizers (13.2KW nameplate capacity), a single 11.4 KW Solaredge inverter, and critter guards
Federal tax credit - 11,127
Cost of electricity (at 0.22 cents inc delivery charges) - $13,200
SREC sales - approx $13,200 (slightly more I lost track, it's at least that much)
Break even time period - 3 years and 4 months
Total home electricity usage in that time - 61 MWh for 98% solar power (will get to 100% soon now that my line problems are fixed). This includes charging 2 Teslas almost daily. I do not have electric heat except for some space heaters when my true-up date approaches nor do I have an electric hot water heater.
Total power imported - 40 MWh
Total power exported - 39 MWh
Self-powered percentage - 33% (I only use my Powerwalls as backup)
Best production day - 96 KWh (May 31st) - this is equivalent to 8.4 hours of maximum production at 11.4 KW -clipping for over 5 hours
Winter solstice production (100% sunny) - 40KWh - Maximum power 8.7 KW
Average production - 49KWh <--- surprisingly high considering cloudy and rainy days
Best Production Month - tie between June and July at 2.12 MWh
Months where the system has exceeded 2MWh production - May, June, July, August
Lowest production month - no snow January 685KWh, snow covered February 384KWh
Problems encountered:
1) Low line voltage resulting in a loss of about 1-2 MWh because of the system tripping off on hot days. Fix required a transformer to be installed on my utility pole, which took 3 years for PSE&G to complete. It added a month to the break even period and kept me from being 100% self-generating so far.
2) Solaredge Inverter failed 2 years in. Luckily I did not go with Tesla for my install so my installer installed a replacement in less than 5 days.
Lessons learned:
1) Don't bother cleaning the panels, it doesn't make any appreciable difference but
2) If you need solar after a Winter storm because the power went out... you're gonna have to get on the roof in treacherous conditions (NOT recommended) to clean off at least some panels.
3) Get as many panels as you can, you can never have too much power if you have electric cars or electric heat!
4) For my location the best true up date with the utility appears to be in the beginning of March as I've used all my excess by then.
Overall I'm very satisfied with the system performance. I did not include the cost of my 2 Powerwalls in the calculations as I got those separately and in lieu of a generator which would have cost me just as much to install as the Powerwalls (after the tax credit). And yes I realize I would have made money investing the $37K instead, but I could have also lost my shirt doing that.
Cost of system (in 2019) - $37,090, consisting of 40 330 watt Panasonic panels with optimizers (13.2KW nameplate capacity), a single 11.4 KW Solaredge inverter, and critter guards
Federal tax credit - 11,127
Cost of electricity (at 0.22 cents inc delivery charges) - $13,200
SREC sales - approx $13,200 (slightly more I lost track, it's at least that much)
Break even time period - 3 years and 4 months
Total home electricity usage in that time - 61 MWh for 98% solar power (will get to 100% soon now that my line problems are fixed). This includes charging 2 Teslas almost daily. I do not have electric heat except for some space heaters when my true-up date approaches nor do I have an electric hot water heater.
Total power imported - 40 MWh
Total power exported - 39 MWh
Self-powered percentage - 33% (I only use my Powerwalls as backup)
Best production day - 96 KWh (May 31st) - this is equivalent to 8.4 hours of maximum production at 11.4 KW -clipping for over 5 hours
Winter solstice production (100% sunny) - 40KWh - Maximum power 8.7 KW
Average production - 49KWh <--- surprisingly high considering cloudy and rainy days
Best Production Month - tie between June and July at 2.12 MWh
Months where the system has exceeded 2MWh production - May, June, July, August
Lowest production month - no snow January 685KWh, snow covered February 384KWh
Problems encountered:
1) Low line voltage resulting in a loss of about 1-2 MWh because of the system tripping off on hot days. Fix required a transformer to be installed on my utility pole, which took 3 years for PSE&G to complete. It added a month to the break even period and kept me from being 100% self-generating so far.
2) Solaredge Inverter failed 2 years in. Luckily I did not go with Tesla for my install so my installer installed a replacement in less than 5 days.
Lessons learned:
1) Don't bother cleaning the panels, it doesn't make any appreciable difference but
2) If you need solar after a Winter storm because the power went out... you're gonna have to get on the roof in treacherous conditions (NOT recommended) to clean off at least some panels.
3) Get as many panels as you can, you can never have too much power if you have electric cars or electric heat!
4) For my location the best true up date with the utility appears to be in the beginning of March as I've used all my excess by then.
Overall I'm very satisfied with the system performance. I did not include the cost of my 2 Powerwalls in the calculations as I got those separately and in lieu of a generator which would have cost me just as much to install as the Powerwalls (after the tax credit). And yes I realize I would have made money investing the $37K instead, but I could have also lost my shirt doing that.
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