10 years of ground mounted grid-tie solar

[mopat]

10 years of ground mounted grid-tie solar. Panels are mounted with a 30.5 degrees pitch. Panels are Canadian Solar CS6P-230P and 20 of them cost $6,624 ($1.44/watt). The grid tie inverter is a Fronius IG4000 which was $2,233.







Monthly data of five and a half years of solar production; production varies significantly with the season.

System went into service 12/1/2011. We signed a 10-year contract with TVA to buy the green energy output at a rate of 12 cents per kilowatt-hour above the retail electric rate for solar and the power company kicked in an additional $1,000 to help offset start-up costs. The system received a Federal tax credit of 30% of the total system cost. The system has required no maintenance and never skipped a beat.

The 4600 watt PV system produced 43,654 kWh over the past 10 years; the utility paid about $9,200 for this power. Over the next 10 years the power company will pay a “flat rate”; paying the same rate as our usage (no premium).

 

[PeSCaLo]

Nice

 

[Bradish]

Loving seeing the actual numbers behind a setup like this. For reference, what part of the country are you in?

 

[mopat]

Loving seeing the actual numbers behind a setup like this. For reference, what part of the country are you in?

Crossville, TN 38571

 

[Mike 134]

With the 10 years in service how did the actual production compare with the PTwatts forecast?

 

[MurphyGuy]

With the 10 years in service how did the actual production compare with the PTwatts forecast?

Probably spot on.. at least it has been for my system going on 5 years now. Yearly totals fluctuate but PVWatts is generally within +/- 2%

 

[mopat]

With the 10 years in service how did the actual production compare with the PTwatts forecast?

PV Watt predicted 4752 kWh per year; actual was 4365 kWh, about 8% less.

 

[Capt. Joel]

Thank you Mopat for that graphical, long-term perspective. That's useful / encouraging for me.
I'm wondering if you knew the premium sales of your farmed electrons would be concluded at the end of 10 years.
It looks like you have grass under your panels, any thought on mowing pros / cons.


Cheers,
Joel

 

[mopat]

Thank you Mopat for that graphical, long-term perspective. That's useful / encouraging for me.
I'm wondering if you knew the premium sales of your farmed electrons would be concluded at the end of 10 years.
It looks like you have grass under your panels, any thought on mowing pros / cons.


Cheers,
Joel

Yes, we signed a formal 10-year contract with our power company which provided a 0.12/kWh premium payment.
Now we are on our second 10-year contract BUT the power company will only pay what we are charged, no more premium.

Actually wild ferns have taken over under the panels, I just let these grow. No mowing under panels.

 

[Capt. Joel]

Wouldn't it be nice if solar-farming was like growing turnips.
I've wondered for a-while, if I have the opportunity to select and buy my electricity from a supplier on the "open market", why can't I buy from my neighbor. I'd Zelle them in a heart-beat.

Thanks again Mopat, The apparent resiliency of these systems is encouraging.

 

[djnorth]

Ground mounted looks convenient to clean to maximize performance

 

[n6ac]

Here is another data point on system longevity –
Installed November 2007, SW corner of Los Angeles area, ground mount on slope south of house.
Location is 33.75, -118.33. Azimuth = 155 deg, tilt = 26 deg.
24 Panels: Kyocera Solar, Inc.:KC175GT
Inverter: PV Powered PVP4800
DC Rating 4.2kW STC, 3.72kW PTC
The dashed line is geometric computation. Colors are the various years.
The graph shows a small loss of performance over the first 15 years.
2008 was a standout in October, but a slouch in February.
2022 was variously more, and less, than 2008.
Overall, year 2008 achieved 75% of the geom calculation; while 2022 achieved 71%.
The shape of the geom curve is due to solar elevation path over the year.
Variations at any given date (note, 30-day average) are due to atmospheric conditions.
We have been charging an e-Golf for 6 years now, so no longer meet our needs completely ...

SOLAR POWER SYSTEM DAILY PRODUCTION HISTORY