legal definition of off-grid

PattiMPattiM Registered Users Posts: 6 ✭✭
I'm hoping for some facts - my understanding of an "off grid" solar system is a solar system in which a 115VAC inverter output connects to and supplies permanent household (for example, the in-wall 115VAC receptacles) wiring, which is to say, wiring which is governed by the NEC.  If there are provisions for switching between a system like this and the public electrical grid, or running both in tandem, then it's considered a "grid-tied" system.  Can someone please comment on this?  I'm mostly interested in any details (or FAQs) on "off grid" systems in Arizona.

Thank You Very Much,
Patricia

Comments

  • petertearaipetertearai Solar Expert Posts: 443 ✭✭✭✭
    That would be my understanding, why do you ask? 
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • Wheelman55Wheelman55 Registered Users Posts: 116 ✭✭✭
    edited June 2019 #3
    Re: “off grid” - might or might not be legal in your community. Might or might not be able to get insurance. Might or might not be able to get a mortgage. Possible that the mortgage that you have now could be cancelled by your current lender. 
    Building Off-Grid in Terlingua, TX
    14 CS 370 watt modules. HZLA horizontal tracker. Schneider: XW6048, Mini PDP, MPPT 80-600, SCP. 1 Discover AES 48 volt LiFePO4 battery 130 ah
  • PattiMPattiM Registered Users Posts: 6 ✭✭
    edited June 2019 #4
    That would be my understanding, why do you ask? 
    Thank you very much for the reply Peter:  I have had a set of solar cells and batteries (800W nominal) that I brought from my apartment in CA that I use here to run a 115VAC freezer in my garage via an extension cord and a 115VAC charger for my electric bicycle via another extension cord.  No connection between inverter and house power, which is fully conventional 115VAC.
    I was thinking of maybe going "all solar" and was considering grid-tie vs non-grid-tie and maybe putting a *lot* of solar cells on the roof, etc.  But then I realized there were lots of code issues in full-house 115VAC systems in either grid-tie *or* non-grid-tie flavors, but I couldn't find a reference for the actual "definition" (in the county codes) of a "non-grid-tie system."  So I asked here - do you have a reference in state/county docs (or the NEC) for that?  Or maybe even some useful terminology for such systems.  It pays to know facts. 
    Thank You Very Much, Patricia
  • PattiMPattiM Registered Users Posts: 6 ✭✭
    edited June 2019 #5
    That would be my understanding, why do you ask? 
    Thanks Peter for the reply:  I brought an 800W system I used in my apartment in CA here and use it now (via extension cords) to run a 115VAC freezer in my garage and a small electric bicycle charger (115VAC) also in the garage.  I was researching upgrading to a roof-mount system with a LOT more cells, but couldn't actually find a definition for what an "off grid system" or a "grid tie system" were in the Yavapai county codes.  So I was asking here.  My house is a regular on-grid system with no connections to solar.  So do you know where I would find definitions, maybe in the NEC?
    Thank You Very Much
    Patricia


  • Dave AngeliniDave Angelini Solar Expert Posts: 5,287 ✭✭✭✭✭
    Ask Yavapai county building department.

     I know from past experience it is not a big issue. In NEC either there is a utility at the home and you are grid tied or, there is no utility and you are offgrid with batteries. As you get into the larger cities offgrid can be an issue but usually there is a way to do it.

     There are various schemes to self consume and not sell to the grid also.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • BB.BB. Super Moderators, Administrators Posts: 30,740 admin
    I don't know about Arizona, but in California, GT Solar (grid tied solar) is an "exemption" to generation of your own power.

    In California, if you currently are on-grid (have utility power to your home, office, etc.), GT Solar is an allowed exemption of local power generation.

    If you, for example, generate your own off grid power (like you are doing), that is "not allowed" by the state public utility rules--As well as simply unplugging the meter and going completely off grid... Basically, the utility has used "your home" to take out loans and build out infrastructure--And if you take your home off grid (even if just using candles and a hand pump for water), you (in theory) have to re-emburse the utility for "stranded costs"... I have not heard of anyone actually having to do this, but is in the rules.

    And many cities/etc. have rules that homes must have utility power/sewer/water (if present in neighborhood)... If you disconnect one or more, the local building department could "red tag" your home.

    On the other-side, we had one member here that built an off grid home, but needed a building permit and inspection... Their building department required a "meter socket" on the main panel to get the final approval... And there is the off grid home with an empty meter socket. And everyone is happy.

    If you start mounting solar panels on your home, and running wiring around the house, there is a good chance that the building department would want to have permits and inspections. Would they come out on their own to hassle you? Probably not, but a local electrician, utility inspector, neighbor that does not like the looks of solar panels on your roof (especially if you are in a home owners' association), somebody could turn you in.

    Lastly, if you had a fire (or solar panels blew off roof and damaged a neighbor's property), and there was any indication that the solar wiring, battery bank, solar components were possibly the source of your fire, your homeowner's insurance company may just walk away as you had an unpermitted electrical system.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PattiMPattiM Registered Users Posts: 6 ✭✭
    edited June 2019 #8
    Ask Yavapai county building department.

     I know from past experience it is not a big issue. In NEC either there is a utility at the home and you are grid tied or, there is no utility and you are offgrid with batteries. As you get into the larger cities offgrid can be an issue but usually there is a way to do it.

     There are various schemes to self consume and not sell to the grid also.
    Thank you very much.  I did ask, but they couldn't specify what constituted an "off grid" solar system - they would only refer to codes which used that term without defining what it meant.  I asked about extension cords vs. the wall wiring and they couldn't help me, at least not the person behind the counter.  So I was looking for the actual term definitions.  The people I know who are "off grid" have systems which connect to their in-wall wiring for running washing machines, kitchen appliances, etc.
    No city here.  County.
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    Seems to me the issue isn't well defined. It might help if you could elaborate on what the problem is or what you're tring to do.

    In terms of NEC, a pv system would generally be defined as a separately derived power source, much like a generator.  

    The NEC requirements for an off-grid system would be largely the same as for an on-grid system.  NEC generally deals with permanent installations (breaker panels, in-wall wiring, etc.).  Extention cords and such temporary installations generally aren't covered.

    FWIW, "off-grid" to me means exactly that.  There is no wire going to the house potentially carrying grid current to the house.  If there's grid going to the house, there's potentially a grid-tied situation.  "Grid-tied" could mean lots of things.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • PattiMPattiM Registered Users Posts: 6 ✭✭
    edited June 2019 #10
    Estragon said:
    Seems to me the issue isn't well defined. It might help if you could elaborate on what the problem is or what you're tring to do.

    In terms of NEC, a pv system would generally be defined as a separately derived power source, much like a generator.  

    The NEC requirements for an off-grid system would be largely the same as for an on-grid system.  NEC generally deals with permanent installations (breaker panels, in-wall wiring, etc.).  Extention cords and such temporary installations generally aren't covered.

    FWIW, "off-grid" to me means exactly that.  There is no wire going to the house potentially carrying grid current to the house.  If there's grid going to the house, there's potentially a grid-tied situation.  "Grid-tied" could mean lots of things.
    Thank you very much for the reply...   Well, most people I've spoken to who have "generators for their house" install fixed generators to automatically start up and manually or auto-switch to supply their house wall-power - this requires a complex permitted/engineered connection.  I have a portable 3kW generator in the garage, but would need to start it up and plug my freezer into it, and then run an extension cord to my house fridge in the event of an extended power outage.  That's what I'm thinking of for my solar system.  Low tech, low convenience.  I'm beginning to realize that "off-grid" means a house where the wall power (115VAC, 15 Amp) is supplied by a fixed local generator/batteries+solar.  But if house-wiring in-wall power is not connected in any way to a local power source (only to the power poles of the public utilities), that means the house is not an "off grid system."  I'm trying to make sure I'm not doing something against NEC or county codes by running a few extension cords from a solar system.

    A second issue: I've been using lead acid batteries - and that's a sticking point.  These batteries are required to have a vented box (hydrogen) by NEC, under all circumstances, I believe.  This may therefore require inspection/permitting.  OTOH: used Leaf LFP batteries do not require this.  So there is a lot to think about.
  • BB.BB. Super Moderators, Administrators Posts: 30,740 admin
    For emergency backup power... Gensets, many times, are the most cost effective. You store them with oil in them, and store fuel (gasoline+fuel stabilizer) or use LPG or Natural Gas for fuel.
    I suggest using as small as practical genset for your loads... If you are just running a freezer and a few lights, a Honda eu2000i (small inverter genset) which uses around 1 gallon of gas every 4-9 hours (depending on loading)--Vs a larger 3.5kWatt genset which may only run 2-4 hours on a gallon of gas (albeit with a larger load)... 1-2 gallons per day vs 10+ gallons per day--Storage issues and finding a local service station with power/fuel in an emergency can be an issue.
    There are many options out there... From full Natural Gas/Propane backup gensets with full automatic start/stop and transfer switches to just a smaller portable genset and some sort of manual transfer switch for whole house, or just a few circuits:
    https://www.homedepot.com/p/GenerLink-30-Amp-Meter-Mounted-Transfer-Switch-MA23-N/301961623 (whole house transfer switch--Plugs into your utility meter socket)
    You can use the small manual transfer switch with most TSW/PSW (True/Pure sine wave) inverters too--If you wish.
    If you have natural gas or a decent size LPG tank, your fuel storage issues pretty much "go away" (gasoline, with fuel stabilizer should be replaced every 6-12 months; and diesel with stabilizer has a limited life too).
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Registered Users Posts: 4,478 ✭✭✭✭✭
    So if the idea is to run critical AC loads off a generator or battery/inverter system in an outage, there are a couple of fairly simple ways to do it:
    1.  Use portable gear (portable genny, RV type solar/battery) with regular AC plugs.  When grid power fails, plug the loads into the portable power.  Be careful with extention cords (especially long runs with undersized wire and large loads like heaters), but there aren't likely any local code issues doing it this way.
    2.  Use a lockout panel for critical loads that lets you pick a power source (grid, or genny/solar, but not both at the same time) for critical loads.  Maybe something like this:
    https://www.homedepot.ca/product/square-d-30-amp-generator-panel-with-18-spaces-36-circuits-maximum/1000722300

    Option 1 is really simple.  There is no connection at all to grid power, and no real NEC issues.  This would not likely need a permit for electrical (but may if there are structures like genshed or battery enclosures involved).

    Option 2 involves having critical load circuits hardwired to the A/B lockout panel.  The hardwired critical load circuits would need to comply with NEC (probably do already), and the lockout panel would need to pass local inspection, but still fairly straightforward (though there may be some grounding stuff to work through if using portable gear).

    I'm not sure battery venting is actually covered in NEC, but is certainly something to consider if using a large-ish bank in a confined space.  Cars with (small) lead acid batteries are kept in garages with no issues.  Bigger banks (10s+ kwh) could be.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • PattiMPattiM Registered Users Posts: 6 ✭✭
    edited June 2019 #13
    I wanted to avoid all connections to the in-wall wiring for the time being.  That's a pretty expensive proposition requiring engineering plans, contractors, and expensive-ish equipment.  Also, it seems aimed at being a bigger consumer of solar energy, requiring a lot of panels - typical in-house wiring is set up for several kilowatts concurrent.  I know I don't have to actually use all that power, but the resale value of a house is an important consideration for many folks.
  • softdownsoftdown Solar Expert Posts: 3,347 ✭✭✭✭
    PattiM said:
    I wanted to avoid all connections to the in-wall wiring for the time being.  That's a pretty expensive proposition requiring engineering plans, contractors, and expensive-ish equipment.  Also, it seems aimed at being a bigger consumer of solar energy, requiring a lot of panels - typical in-house wiring is set up for several kilowatts concurrent.  I know I don't have to actually use all that power, but the resale value of a house is an important consideration for many folks.
    The buzz on resale value of grid tied solar is quite disappointing. in fact a number of new buyers have the panels removed for aesthetic reasons. Bizarre by my way of thinking. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
  • BB.BB. Super Moderators, Administrators Posts: 30,740 admin
    And others are "scared" of all those panels and wiring on the roof of their house...

    I too would not expect GT Solar (or even off grid solar) power systems to have much (if any) positive return on investment for home resale value.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • cjpetriecjpetrie Registered Users Posts: 4
    I built my off-grid system in a rural Texas county. There are simply no lines, pipes, or cables coming onto my property. "NEC" plays no role, though I've tried to follow code. There is no motgage on my homestead, so no inspections other than for the septic tank were required. My detailed experience is published on lulu.com : https://www.lulu.com/en/us/shop/charles-petrie/ten-years-off-grid/paperback/product-1dgpvmym.html
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,287 ✭✭✭✭✭
    Texas is pretty good about Offgrid.

     It is each building department that determines what is good or bad. This is with NEC, NFPA, UL, or any other body that the state has adopted and will be "chosen" to enforced locally. I had one last year during a room addition, that a county decided after 19 years to enforce the building code.

    The inspector tried to tell the people he would have to turn off power, the owner called the sherrif and he said, can I turn it on when he leaves  :) The sheriff told the inspector to leave...  

    Nice job! Stay cool down there!
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • softdownsoftdown Solar Expert Posts: 3,347 ✭✭✭✭
    Per thread title, I think off grid means that the public utility is not supplying power. Others will argue that you are on the grid if you have cell and/or internet. Different grids of course.

    If you also have city water and city septic? Well, city slicker you are.
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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