smkettner
Well-known member
Is it a separate meter reading gross production or reading net of usage?
smkettner said:Is it a separate meter reading gross production or reading net of usage?
DarthPuppy said:Ok, I checked the SCE meter and it appears that over the past year, my 5.8kW (DC) system produced 7400 kWh AC, which exceeded what was used by the house by a little over 1,400 kWh.
smkettner said:Is it a separate meter reading gross production or reading net of usage?
The meter provides two readings. One reading is power drawn from SCE. The other reading is power provided to SCE. I then net the two readings to determine my surplus production.
QueenBee said:DarthPuppy said:If you have one meter that is measuring power sent to the grid and power taken from the grid then you don't actually know how much power your system produced or how much power you produced?
DarthPuppy said:QueenBee said:DarthPuppy said:If you have one meter that is measuring power sent to the grid and power taken from the grid then you don't actually know how much power your system produced or how much power you produced?
Good point. The missing element would be the power produced and used by the house before feeding excess back to SCE. This would suggest that my production is significantly better than 7,400 kWh over the course of a year. So perhaps a 10 panel system would be overkill.
I now have a little more thinking to do.
Maybe it was answered somewhere but I didn't see it: "Wp" is Watts Peak, i.e. under (rated) peak power conditions.DarthPuppy said:RegGuheert said:would equate to about 3000Wp PV panels (grid-tied).
So 3,000 W is the spec I need to tell the installer that I want to add to my system? Or am I mis-translating? What is a "Wp"?
Thanks!!!
That sounds like a nice addition to your system, assuming your roof and your wallet can handle it.DarthPuppy said:I now have a proposal for 10 SolarWorld (US made) 250 panels with Enphase M215 inverters. That study is estimating a little over 3700 kWh over a year.
From what I've gleaned from these posts, that should cover at least 13,500 miles in my Leaf. Since this past month's driving suggests I'll do 14,000 miles over the year, that size should work well for me. 2 fewer panels and I likely won't have full coverage. 2 more panels and I'll likely be supplying more excess to SCE than I'm interested in.
That is only true if you use a tracker OR the inverter limits the output. Otherwise, the curve looks almost exactly like a bell (no flat top).ERG4ALL said:I was told by the Enphase people that they intentionally have more panels with smaller inverters because the generation on a daily basis is a bell curve with a flat top.
All PV inverters will clip if you send too much DC power to them. Higher rated inverters simply start clipping at higher power levels.Burr said:ERG4ALL- Thanks for the info. I never really understood the the " flat part of the curve before". I wounder how that would apply to the newer microinverters that are made for larger solar panels. SMA, Energy One, and Enphase are the only companies I know of that address the need for those solar panels above 255 watts.
SMA has had this for a while using their Sunny Island product - the Sunny Island integrates with existing SMA inverters.Burr said:One last note SMA has anew line of central inverters that will shift from "grid" to non-grid DC production during a power outage. My older central inverter systems may need replacement some day. These new SMA would be a nice adaptation. Right now, expanding the older array with microinverters for my Leaf is working out fine.........Thanks again.
The Sunny Boys are well designed and manufactured. The difference is that you only get a 10-year warranty with them instead of the 25-year warranty with the M215s. That is mainly due to the electrolytic capacitors that the Sunny Boy uses. The good news is that you can pay extra to get a 25-year warranty on the Sunny Boy if you like. By way of anecdotal information, DesertDenizen has stated in my thread on MTBF, failure modes, etc. that his lower-power Sunny Boys have served him without any problems for over 10 years in Arizona. Of course no one has that much history with any Enphase inverters.DarthPuppy said:Anyone have these installed and can speak to their quality?
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