Hi Wes and everyone else. I’ve heard from Enphase and Fronius offsite and indeed its quite possible to do “self consumption”. Both Enphase and Fronius need some additional hardware but thats to be expected and pretty minor really. SMA and SE both are supposed to do it but I didn’t pursue exactly what they need to do it, but I’m presuming they also need additional hardware to read the main. At this point nobody is reading the smart meter, but that would be the easiest and most accurate. Maybe when sunspec comes out it will be able to interface?
This whole question started from an old client up in SE alaska, who’s utility no longer accepts NEM. He’s got a lot of sun during the summer and not much in the winter as well as lots of clouds, which to me means that a battery system isn’t going to do much. And given how inexpensive GTWOB is, vs adding batteries its an interesting option. In his case I think the self consumption option is a good one. In other areas with different price structures it might be totally different. And I’m sure will have an impact as to what size system might be the most economic. The Fronius has a relay option that will turn loads on/off based on curtailment. As to load peaks, those of us off grid folks understand to do it when the sun shines and to me I think we will see more and more smart day time load use as we see more and more renewables come on line during the daytime. Thanks again everyone, jay > On Aug 29, 2019, at 11:07 AM, wes kennedy <hathaso...@yahoo.com> wrote: > > HI Jay, > > The Fronius line, primo or symo have that capability. You need the smart > meter to measure current flow at point of interconnection. > The tricky bit is what happens when a big load suddenly turns off. There will > always be a small flow of energy across the meter for a second or two while > the system reacts and curtails the pv array. > HECO was fine with this limited, momentary export of energy. > These residential systems typically have very low performance factors, as the > PV peaks around noon, when a typical load profile peaks morning and evening. > So you end up curtailing most of your pv production. > In a commercial application though, zero export can work really well, if you > size PV to midday loads. > > -Wes Kennedy > >
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