Idea for excess power

jcheil
jcheil Solar Expert Posts: 722 ✭✭✭
in Advanced Solar Electric Technical Forum #1
Ok, I have this idea, which may be far fetched, but would like some opinions.
I generally produce an excess of power. Usually by 1-2pm I am floating.

Is there a way to take that existing power that I could be producing after that time and "give" it to my neighbor to assist in his charging?

A direct wire run would be about 250'. However, we are lucky in that he already has a 500' roll of #2 AL 3 conductor wire (courtesy of the electric company) available for free. So what would normally be the biggest expense of doing this (if it CAN be done) is taken care of.

I am on a 24v system (see sig) and have an FM 80. He is on a 12v system with a C60 and a C35.

EDIT: last minute idea, or maybe send AC to him to run a charger?

Any ideas are appreciated. Thanks.
Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #2
    Re: Idea for excess power
    jcheil wrote: »
    Is there a way to take that existing power that I could be producing after that time and "give" it to my neighbor to assist in his charging?

    A direct wire run would be about 250'. However, we are lucky in that he already has a 500' roll of #2 AL 3 conductor wire (courtesy of the electric company) available for free. So what would normally be the biggest expense of doing this (if it CAN be done) is taken care of.

    I think the most cost effective solution is to buy your neighbor a couple more solar panels.

    If you do connect a cable to your neighbor, be sure not to get a headache thinking about the implications for grounding and lightning protection.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    #3
    Re: Idea for excess power
    vtmaps wrote: »
    I think the most cost effective solution is to buy your neighbor a couple more solar panels.

    If you do connect a cable to your neighbor, be sure not to get a headache thinking about the implications for grounding and lightning protection.

    --vtMaps

    Unfortunately he is maxed out on his solar (based on controllers).

    Next step would be to convert him to 24v - which I have thought of, but IF my idea would somehow work it would be cheap in the long run (since we already have the wire). And yeah, lightning...
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • waynefromnscanada
    waynefromnscanada Solar Expert Posts: 3,009 ✭✭✭✭
    #4
    Re: Idea for excess power

    There is also to consider, the present friendship between you and your neighbour. All is wonderful as you provide him or her with "free" electricity. Down the road it becomes your "duty" to supply, they've learned to depend on it and consider it their own. Then when you need more than you're presently using and so cut back on what you're delivering for free, suddenly you're the bad guy and everything goes downhill from there. Human nature. Sometimes it's just best to maintain a certain distance. That old saying: "Good fences make good neighbours." Tear down that fence and what's yours is mine, and what's mine is mine.
    Just something to consider.
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  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    #5
    Re: Idea for excess power
    waynefromnscanada wrote: »
    There is also to consider, the present friendship between you and your neighbour. All is wonderful as you provide him or her with "free" electricity. Down the road it becomes your "duty" to supply, they've learned to depend on it and consider it their own. Then when you need more than you're presently using and so cut back on what you're delivering for free, suddenly you're the bad guy and everything goes downhill from there. Human nature. Sometimes it's just best to maintain a certain distance. That old saying: "Good fences make good neighbours." Tear down that fence and what's yours is mine, and what's mine is mine.
    Just something to consider.

    True, but we are a rather unique community here. Everyone depends on everyone else in some way so nobody ever takes anything for granted. Sure that could change based on typical human nature, but unlikely since we all have the same like mentality. I suppose I could always put an electric meter inline and charge him :)

    But all "human" issues aside, I would be interested in people's opinions on how to do this, regardless of cost and complexity.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,631 admin
    #6
    Re: Idea for excess power

    Sending him AC power or higher voltage with a DC regulator at his end... But there you go--Another piece of electronics (battery regulator) or, at least, wiring up an existing charge controller (from backup genset).

    You just need to install an On/Off AC relay at your end controlled by your charge controller (Midnite/Outback/Voltage Controlled Switch) to cycle the AC to his local AC battery charger.

    It will work, and with AC, you get isolation (running DC to his place just makes grounding/lightning issues worse/more complex).

    Depending on the size of your system and his AC battery charger--You could end up with some "pulsing" of your local AC power (i.e., your lights/audio-visual equipment may change a bit with 110-120 VAC cycling of remote loads).

    Another issue may be the input to the remote AC battery charger--It may not last quite as long. Cycling AC power (perhaps as often as every few minutes to every few seconds--depending on how you set up your "waste not" power sharing) can stress the AC input stage (surging rectifier/high voltage capacitors).

    Just setting up the power cable run (poles or buried in conduit) seems to be a fair amount of work/costs in themselves.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    #7
    Re: Idea for excess power
    BB. wrote: »
    Just setting up the power cable run (poles or buried in conduit) seems to be a fair amount of work/costs in themselves.

    -Bill

    Well, he is retired, so he has plenty of time :)

    Do you have a specific recommendation (link) to a relay to use with my FM80 for this purpose?
    And perhaps a suggestion on the settings in the FM80 for this application?
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,631 admin
    #8
    Re: Idea for excess power

    A transistor based relay ("digital") would be a could option here (no contacts to fail):

    http://www.phidgets.com/products.php?product_id=3953_0

    However--Make sure it has a good heat sink (these things can dissipate more heat than a normal mechanical relay--Yes, more losses). But you should be able to connect the signal directly from the Outback to the relay.

    I do not know anything about programming the FM80--There is an "in float" function (I believe) that you can use to program the FM80's output signal. You may have an issue with setting up a time delay (i.e., you probably want to cycle the relay on for ~1 minute minimum rather than have it chatter a few times a second). Could be an issue where the remote load takes the FM80 "out of float" (if AC loads are greater than array output at that moment in time).

    You might also want to put a timer on the output (to export power only from noon to 5pm) and some sort of "exporting" LED in your home so you don't have a failure somewhere kill your battery bank (AC relay shorts, FM80 software crashes, etc.).

    The Midnite has a "waste not" function built in with programmable PWM parameters designed for this type of application.

    The whole "fail safe" is (for me) a big issue... It is very nice that you can share power with your neighbor--But you are taking on some additional risks of damaging your battery bank/etc. (somebody else pulling power from your system) because of this.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • jcheil
    jcheil Solar Expert Posts: 722 ✭✭✭
    #9
    Re: Idea for excess power
    BB. wrote: »
    You might also want to put a timer on the output (to export power only from noon to 5pm) and some sort of "exporting" LED in your home so you don't have a failure somewhere kill your battery bank (AC relay shorts, FM80 software crashes, etc.).
    -Bill

    Excellent point! I too am all about the "backups" and "what-ifs".

    Now I am thinking, I wonder if it would be better for me to use an additional small inverter for this circuit over to him or just have this relay control an additional circuit on my main panel fed from my inverter. I am leaning towards an additional one myself even though that is an additional cost.
    Off-Grid in Central Florida since 2005, Full-Time since June 2014 | 12 X Sovello 205w panels, 9 X ToPoint 220w panels, 36x ToPoint 225w panels (12,525 watts total) | Custom built single-axis ground mounts | Complete FP2 Outback System: 3 x FM80, 2 x VFX3648, X240 Transformer, FLEXnet-DC, Mate-3, Hub-10, FW500 AC/DC | 24 x Trojan L16RE-B Batteries 1110ah @ 48v | Honda EU7000is Generator and a pile of "other" Generators | Home-Made PVC solar hot water collector | Custom data logging software http://www.somewhatcrookedcamp.com/monitormate.html
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #10
    Re: Idea for excess power

    I'd send him the AC power, as high as voltage as you can, to reduce loss. 240VAC is good, if you can get a pair of transformers - boost it to 480V, and you may even get some isolation from system "disturbances" (lightning) and some galvanic isolation. Or just send 240VAC (fused with good HV rated fuses at each end.) and he'd need an appropriate battery charger.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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  • Calimobber
    Calimobber Registered Users Posts: 2
    #11
    Re: Idea for excess power

    I was thinking in mikes terms. Why not just run your inverter and run an extension cord over to his house charge his batt via battery charger(I know is inefficient but all these options are)... hummm idk might run into problems confusing his charge controller but it seems since his controller is maxed so you cant add 12v solar to it anyways. idk just thinking out loud :)
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  • AceNZ
    AceNZ Solar Expert Posts: 104 ✭✭✭✭
    #12
    Re: Idea for excess power

    The best approach depends on existing equipment and how much you're both willing to spend to get everything aligned and safe.

    If you were *my* neighbor, I would just ask you to provide an extension cord with 240VAC, with some guidelines on maximum power allowable power draw, and I'd plug it into the second (generator) AC input on my inverter/charger. A few minor config changes, and it would be ready to go. Easy.

    OTOH, I'm not sure I'd want an extension cord draped across my yard forever -- but that's just me.
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