These days, most new Air conditioners are variable speed for maximum efficiency. This means they rectify line voltage to DC and then run everything internally off of DC. This means you can run them on high voltage DC just as well as AC. Some manufacturers even advertise them that way. You can hook up 3 or 4 solar panels to them (DC at 90 to 120 VDC) and they will parallel into the DC system and run on sunshine or grid. And these are NOT special systems. They are regular low cost mini-split AC/Heatpump units that simply happen to run internally on rectified DC.
These are an ideal use of solar in a non-grid tied system. But again, only of 50% value,because in the spring and fall, you dont need AC or heat and so your 4 solar panels are doing nothing. But using about 4 Solar panels for the bottom coil in a water heater are a good idea. You need hot water every day, and so this gives you 100% effectiveness of these 4 or so panels. Just be sure you fully understand the consequences of a switch (plazma) when switching DC. These are just some of the DIY uses of solar panels in the ARRL book http://aprs.org/Energy-Choices.html Bob On Mon, Jul 15, 2019 at 2:20 PM paul dove via EV <ev@lists.evdl.org> wrote: > That's good, all the inverters I have seen disconnect the solar panels > when the grid goes down so you loose power from your own system to protect > line workers. I never liked that configuration. > > The last time we had a 3 day power outage was in August in Alabama. It was > hot and muggy and no hot water.... oh and the gas pumps were out so you > couldn't buy gasoline because the had electric fuel pumps. Some of the > stations got generators and were pumping gas after a day but not all. > > > On Monday, July 15, 2019, 8:40:54 AM CDT, Robert Bruninga via EV < > ev@lists.evdl.org> wrote: > > > a $250 generator won’t power your house. Maybe a few appliances. > > > > Can do mine. I need about 100W to power all the lights in the house that I > need (20 or so LED's) > I need about 250W to power the refrigerator (50% duty cycle) > > A small generator can do that nicely! > > I do not need anything else during grid down. But then I have not used a > generator in years. I just plug the house into the 2 kW available from My > Chevy Volt. Or the 1 kW from the Prius. > > Dont need no stinkin generator. > Oh, and while the sun is up, I have 16 kW of solar power...(DC, but the > Sunny Boy inverters now include 1.5kW of grid-down AC as well per > inverter)... > > Bob, Wb4APR > > > > > > On Jul 13, 2019, at 6:15 PM, Robert Bruninga via EV <ev@lists.evdl.org > > > > wrote: > > > > > > WHen you go grid-tie solar, nothing changes. you do the same thing you > > did > > > before. A $250 generator and a $15 can of gas is far more cost > > effective > > > to produce a few dollars worth of power outage comapred to a $13,000 > > > battery to produce $2 worth of power (a 14 hour outage)... Bob > > > > > >> On Sun, Jul 14, 2019 at 7:05 PM paul dove <dov...@bellsouth.net> > wrote: > > >> > > >> One thing I haven’t seen mentioned is power outage. If the grid goes > > down > > >> with net metering so does you solar. > > >> > > >> You have to be off-grid to stay powered when the grid fails. > > >> > > >> Sent from my iPhone > > >> > > >>> On Jul 14, 2019, at 11:16 AM, Robert Bruninga via EV < > > ev@lists.evdl.org> > > >> wrote: > > >>> > > >>> But why are you so determined to use batteies when the cost of grid > > power > > >>> is ditrt cheap. > > >>> > > >>> a 1kwh deep cycle lead acid battery might cost $100. It will store > 10 > > >>> cents of electricity per day. > > >>> After one year it is SHOT. that is $100/365 days or about 27 cents > per > > >>> kWh. So you are paying TRIPLE the cost of electricity just for a > > battery > > >>> compared to just getting it from the grid? And this does not even > > >> mention > > >>> the cost of solar panels. This is purely battery storage costs. > > >>> > > >>> Even if you find magic battteries that can do 1000 discharges before > > >>> replacement, that still is 10 cents per kWh storage cost and still > does > > >> not > > >>> even count the cost of solar to get the energy inthe first place. > > >>> > > >>> AND, unless you do a full cycle of thebattery everyday, to use y our > > >>> incoming solar, then you are not fully using your array.investment. > > Sure > > >>> you can throw away all kinds of money at this problem, but nothing > > >> canbeat > > >>> being grid-tied and a net meter. Just do it. Do a small system at > > >>> contractor prices... then add panels at your leisure and at 20% of > the > > >> cost. > > >>> > > >>> bob > > >>> On Sun, Jul 14, 2019 at 10:50 AM Peri Hartman via EV < > > ev@lists.evdl.org> > > >>> wrote: > > >>> > > >>>> Actually, I am proposing something simpler than a power wall - that > > does > > >>>> not feed back to the grid. Maybe that simplification doesn't reduce > > the > > >>>> cost of the battery system much, but it would reduce the legal paper > > >>>> work down to a normal electrical permit. > > >>>> > > >>>> Peri > > >>>> > > >>>> ------ Original Message ------ > > >>>> From: "Willie via EV" <ev@lists.evdl.org> > > >>>> To: ev@lists.evdl.org > > >>>> Cc: "Willie" <wmckem...@gmail.com> > > >>>> Sent: 14-Jul-19 7:30:58 AM > > >>>> Subject: Re: [EVDL] Solar off grid with an EV? (transformers) > > >>>> > > >>>>> > > >>>>> > > >>>>>> On 7/14/19 9:06 AM, Peri Hartman via EV wrote: > > >>>>>> How hard would it be to build a battery system that normally > > supplies > > >>>> 100% of the domestic power but, when depleted, switches over to > supply > > >>>> domestic power from the grid ? Also, I think it would be safe > > >> assumption, > > >>>> or at least a reasonable simplification, to assume that the battery > is > > >>>> always sufficient for the load, except when depleted. The battery > > would > > >>>> always be charging from a solar array, never from the grid. > > >>>>>> > > >>>>>> It seems to me, a system like this would completely circumvent any > > >>>> negative conditions imposed by power companies. Of course, once the > > >> solar > > >>>> panels fill the battery, excess production is lost. > > >>>>> > > >>>>> You have described a PowerWall. The battery is one or more units > > that > > >>>> will supply or charge 5kw and holds 13-14kwh. If about 11kwh will > > carry > > >>>> you over night and if you don't use more than 5kw over night, a > single > > >>>> battery unit will serve you. With good sun, day time self power use > > >> can be > > >>>> around 20kw, including car charging. > > >>>>> > > >>>>> In 5 or so months, I have bought less than 10kwh from my utility > and > > >> sold > > >>>> them something like 10,000 kwh. That is with one battery unit. > > >>>>> > > >>>>> Cost installed was about $13k. For smooth operation, I am highly > > >>>> dependent on the utility to accept my excess power. > > >>>>> > > >>>>> _______________________________________________ > > >>>>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > >>>>> 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 > > >>>> 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/20190714/9cbd7158/attachment.html > > >>> > > >>> _______________________________________________ > > >>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > >>> 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/20190713/f4fdb073/attachment.html > > > > > > _______________________________________________ > > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > > 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 > > 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/20190714/1405062d/attachment.html > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > 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/20190715/4ae1ff56/attachment.html > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > 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/20190714/6ca64a42/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
