Year 2 with our solar (PV) system

[Codyroo]

3.8 kw AC system.

Year 1 = ~6700 kwh generated and net usage was 7 kwh. Total credit at "trueing up" date was $245.

Year 2 = 6750 kwh. Net usage was ~-350 kwh. Total credit at trueing up date was $330.

So, for the last 2 years, my electric bill has been $200 (unavoidable fees such as distribution, generation, and public purpose programs), instead of $3000. Doing the right thing AND saving money.

[icarus]

Very nice,

by my calcs. you are averaging ~18 kwh/day,,, not bad for a 3.8 kw system.

Good luck,

Icarus

[ronhowell]

Originally Posted by icarus

Very nice,

by my calcs. you are averaging ~18 kwh/day,,, not bad for a 3.8 kw system.

Good luck,

Icarus

I find that impossible to believe!
If he has a nominal 3.8kW panel set ( which I have too), then with an efficient set-up he is probably producing no more than 3.2 kW at maximum solar isolation, around mid-day. Even ignoring system efficiencies, 18 kWhr/3.8 = 4.73 hours of power output at maximum daily! Impossible, unless Codyroo has an optimized solar tracking system for both azimuth and elevation. Even then, I find it difficult to believe!
FWIW, I too have a 3.8kW (19 Sharp 200W panels) solar set-up down here in Southern California, with a pretty high level of solar isolation. it is now approaching its 2nd year since originally installed. From April 2008 though April 2009 total solar production amounts to 3,498 kWhrs, or around 8.81 kWhrs per day.

[icarus]

You make a good point, That would be in excess of ~ 5 hours at name plate rating 365 days per year. Not very likely. In the real world you would need better than a 6 hour average @ 80% of name plate over 365 days, also not very likely.

Perhaps the OP's numbers are wrong, or my interpretation of them is wrong.

Icarus

[Cacti]

The first 11.5 months our 2.88 kw PV system produced 3464 kWh's

[icarus]

Somewhere around 1/2 of the OP's output,, more realistic.

Icarus

[Codyroo]

4.5 kw DC system, coming out to a 3.8 kw AC system. I "believe" it has 24 x Sharp 187 panels (don't have the booklet at work) and a Sunnyboy Inverter (4000 kw?). 12 panels facing south, 12 panels facing west (our southern exposure isn't very sizable in square footage).

Reading on the inverter the morning of August 4th, 2008 was 7000 kwh produced. This year on the morning of August 5th, 2009, it was 13750 (or so).

Often times, the inverter will be reading in the 3200 - 3300 range during the day, with typical max production around 3400 - 3500. If I "hose it down" and cool it off, it will shoot up to 3800 or so for a little while.

I don't have a way to print it out from the inverter and there is no software associated with it.

Don't know if that helps or not. Pics taken on June 6th, when we had generated as much electricity as we have used (system went live on August 3rd 2007, although we had run it for a few weeks prior to our "go live" date".







So we were at 12161 kwh on June 6th, thus have generated approximately 1589 kwh in 60 days for about 26.5 kwh per day. Which is about right, we typically run between 27 - 29 kwh/day this time of year with the uncommon "gust" into 30.5 kwh/day.

[icarus]

4.5 DC makes a bit more sense,

Thanks for the clarification.

Icarus,

PS My real world experience is mostly with off grid Pv systems that have very different efficiency curves.

[Codyroo]

Originally Posted by icarus

4.5 DC makes a bit more sense,

Thanks for the clarification.

Icarus,

PS My real world experience is mostly with off grid Pv systems that have very different efficiency curves.

I remember the salesman telling me that the 4.5 kw was not what the panels would do (losing efficiency when converting to AC), which is why I will state the AC potential of the system. Sorry for any confusion it may have caused.

The other nice thing is that we have a $300 surplus (currently) per year which COULD go to deferring the cost of a PHEV...oh...one day....

[icarus]

In the off grid world, total efficiencies (losses from, wiring, charge controllers, basic battery charging losses, inverter losses etc) aproach 50% of name plate rating. So a 2 kw system, net/net might put out 1kwh of power for every hour of good sun. We like to use ~4 hour average, so that 2kw system might put out ~ 4-6kwh/day usable out the inverter.

Icarus.