Where I live, the local utility has some odd rules, but I do get credited $0.06968 for each kWh given back to the grid. I have a permitted 4 kW array that feeds a Darfon/Panasonic inverter/charger for a 15kWh (useable) battery that was commissioned in January. The battery covers times when the panels aren’t putting out enough to power the house, such as overnight. Overnight, the house uses two or three kWh that comes from the battery. In the morning the battery recharges, and is typically done charging around 10:30 in the AM. After that, any excess is sold.
This inverter/battery setup has been working very well. The battery has not been below about 50% so far, and that was during a three-day rain event where the system wasn’t producing much. Aside from those (somewhat rare) rain events, I generally have around 10-20 kWh excess that is sold back to the grid daily. One quirk of this inverter is that in certain conditions, it goes into ‘standby’ (in the power delivery mode I’m using - it has several custom delivery modes). The inverter goes into standby mode when the house load is less than around 100-150 watts, and the panels aren’t producing power (like at night, with lights turned off). Between refrigerator cycles at night, the standby consumption ends up being around 1 kWh per day. In other words, although I am producing several hundred kWh per month, I am also buying about 30 kWh per month. Each month, I have a ‘credit’ of anywhere from $10 to $35, which rolls forward for a year, At the end of the year, any credits not used are expired. So, it is not exactly net metering, but a combination of buying a bit, and getting credit for kWh produced. My power bill used to be anywhere from $80 to $150 a month. The highest bills were from November through January due to Xmas lights, small space heater use, and driving the EV more to visit people. I have not had a bill that required payment since the system was commissioned. When I am driving (not driving much at all these days due to shelter in place) I typically drive less than around 30 miles per day. I normally can plug in the EV around 2:30 or so, and the 30 miles (around 7.5 kWh) is charged back up in a couple of hours. I normally try to keep the charge current somewhat low to ensure I am not drawing off the grid when charging. Occasionally, the car takes a bit (1-2 kWh) from the house battery when charging, but the house battery gets recharged quickly the next morning. A typical day’s excess generation (10-20 kWh) means I can drive up to 80 miles a day without drawing from the grid. Again, 80 miles is well beyond my typical driving needs. I only have one vehicle, and it is battery electric (Hyundai Kona EV). This particular inverter/battery setup can be completely islanded. I’ve done that for a few days at a time, and the inverter handles the power used by the house very well. As when grid-tied, the battery typically doesn’t go below 70-80% of charge - the discharge cycle is 20-30% of nominal capacity. There is excess once the battery chargers, but the inverter simply provides what the house needs (like an ICE generator) and doesn’t need to ‘bleed off’ any excess, like some have suggested. If this system were used in an off-grid house, it would perform like I have done by disconnecting the grid connection. It also has a ‘dark start’ mode for situations when the grid isn’t available, such as an off-grid house. The system is more than just a set of panels an an inverter, but I like it the way it is - suits my needs very well. Tl;Dr - I have a 4 kWh solar array and 15 kWh battery system that runs the house and charges my EV. Tom Keenan > On May 28, 2020, at 7:16 AM, Robert Bruninga via EV <ev@lists.evdl.org> wrote: > > Wow, that is a travesty. Utilities should not be allowed to get away with > that kind of greed. > > > > I’d say that ALL 16 kW of my solar production in the spring and fall and > most of the summer is EXCESS (when generated) since we don’t run AC except > on the hottest week or so of summer, and the only thing running is the > cycling of the Refrigerator. So almost all of our production is banked in > the grid via NET metering until we use it for the 12 hours of sundown and > almost continuously in the winter for heatpump heat. > > > > Not allowing homeowners to contribute to the grid during peak solar days > when the utility needs it most is a travesty of utility greed and > illiteracy of the community politcians. (in my humble opinion…) > > > > Bob > > > > *From:* Bobby Keeland <keela...@gmail.com> > *Sent:* Wednesday, May 27, 2020 4:58 PM > *To:* Electric Vehicle Discussion List <ev@lists.evdl.org> > *Cc:* Robert Bruninga <bruni...@usna.edu> > *Subject:* Re: [EVDL] : V2g for DIY EV's (economics) > > > > Robert Burnings said "With GT, there is no such thing as wasted, or excess > power, its all converted to $$$ on your electric bill." > > > > That all depends on your local electric company. When we produce more > electricity than we use the excess does go to the utility. We are not paid > for that electricity like people are in some other locations (States?). We > just get a VERY SLIGHT reduction in the cost of any electricity that we buy > from the utility at night. > > > > To make matters worse our local electric utility is no longer installing > net meters when any customer adds solar panels to their home after January > 1, 2020. I assume that anyone in my area that adds solar panels will have > the same situation that we had before we got net metering. Electricity that > we got from the utility we paid for. Any of our "excess electricity" that > we generated went to the utility, and we also paid for that. There is/was > any $$$$ in our case. > > > > Dr. Bob Keeland > > Louisiana > > > > On Wed, May 27, 2020, 3:11 PM Robert Bruninga via EV <ev@lists.evdl.org> > wrote: > > I disagree. When you make a $10,000 investment in a solar array, any sun > that falls on it and does not give you retail value in return for the > electricity is truly a wasted economic value. With GT, there is no such > thing as wasted, or excess power, its all converted to $$$ on your > electric bill. And that is what lead the Solar explosion about a decade > ago. No batteries, no maintenance, but economic power for life... at > Half the cost of the utility... > > Bob > > -----Original Message----- > From: EV <ev-boun...@lists.evdl.org> On Behalf Of Lee Hart via EV > Subject: Re: [EVDL] : V2g for DIY EV's > > Willie via EV wrote: >> BTW, I believe someone mentioned that the not produced power when an >> inverter "cuts back" must be dissipated somewhere as heat. I don't >> believe that is the case; I believe the inverter can just not produce >> the available power with no heat generation. > > I agree. It would be a stupid design that burned it up as heat. Any sane > design would just turn off or throttle back the inverter. The energy isn't > "wasted" any more than the sunlight that falls on a sidewalk or street is > "wasted". > > It does lead to an interesting question: If you have excess electric > power, what can you do with it to accomplish some useful purpose? > Provide free public EV charging? Light up a greenhouse to grow more food? > Run a freezer to store more food? > > Lee Hart > > -- > When something bad happens, you have three choices: You can let it define > you; let it destroy you; or you can let it strengthen you. > -- Theodor Seuss Geisel > -- > Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA > (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20200528/12f97dcb/attachment.html> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > ARCHIVE: http://www.evdl.org/archive/index.html > INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub ARCHIVE: http://www.evdl.org/archive/index.html INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
