Questions about grid tie procedures.

If I wire up my 25 panels through my combiner and through the kill switch and my meter whom do I hire to finish the wiring to the grid? Do I contact the electric company first before the job is even done or what is the procedure to follow? I wonder how much I will get stuck paying for hooking up 4 wires where needed? The panels will be ground mounted so no permit is needed there.

Thanks.

Comments

  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Questions about grid tie procedures.

    Welcome to the forum.

    Yes, if you are installing a grid-tie system you need to talk to the utility. They're not all the same, and each one may have different requirements for you to follow.

    The same goes for your local building/code inspector. The wiring all has to be done to meet code, and there can be variations in that by locality as well.

    The way you express yourself indicates you may not grasp just how these systems work. You've left out the word "inverter", which is an integral part of the system. Different inverters will have different requirements for panel configuration, and the panels themselves will have varying specifications which enter into the design. Not to mention the back-feed power restrictions and circuit protection requirements.

    In theory you can do the job yourself providing it meets code and passes inspection. Some locales do require a licensed electrician to at least 'sign off' on the wiring. Others do not.

    I'm sorry this answer sounds dreadfully vague, but the rules aren't the same everywhere you go.
  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    Re: Questions about grid tie procedures.

    I am guessing you are in the Memphis Tennessee area... So, somebody out there may be able to help.

    DSIRE has some information specifically for Tennessee. You can see if anything applies to you. There appear to by ~10 different utilities in your area--Need more information before anyone can help much.

    In general, before you start, you need to contact your utility. You cannot legally connect until you meet the utility's requirements. Some will want permits, specific installers, insurance, etc.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • peakbaggerpeakbagger Solar Expert Posts: 341 ✭✭✭
    Re: Questions about grid tie procedures.

    Most utilities but not all need the system installation signed off by a master electrician or building inspector before connecting. If there are incentives involved many programs require a site audit in advance of the installation. Everything needs to be complaint to whatever version of the electric code in effect in your area. The grid ties inverter usually needs to be approved by the utility which generally means that it must be a UL 1741 rated, most fleabay inverters are not.

    Keep in mind that home insurance will typically not cover a loss associated with non legal installation.
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Questions about grid tie procedures.

    It can get even worse. Here they require a structural engineer to sign off on the roof loading of adding panels and get a building permit for such inspection. This along with the electrical design signed off by an electrical engineer to pull that permit.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Questions about grid tie procedures.
    solar_dave wrote: »
    It can get even worse. Here they require a structural engineer to sign off on the roof loading of adding panels and get a building permit for such inspection. This along with the electrical design signed off by an electrical engineer to pull that permit.

    In this instance the OP says they will be ground-mounted, so he won't have that to contend with.

    And yet ... some areas have specific rules for ground mounting as well, to deal with issues such as wind and soil compaction. If you build a structure to hold the panels up off the ground it may require building permit, depending on the size and type.

    Rules, rules everywhere and not a brain to think;
    Rules, rules everywhere bureaucracy doth stink.

    (With apologies to Coleridge.)
  • DarkAlchemistDarkAlchemist Registered Users Posts: 12
    Re: Questions about grid tie procedures.

    Inverters will be of the micro inverter type out at the panels. As far as where I live it is currently under the evil reign of MLGW where I can't have water and/or gas from them if I go off grid for electricity and codes dictate I am not allowed to have a private well for private consumption within the city limits (yes, they are crooked as it gets here and why I am leaving as soon as I can). Gotta love an all in one monopoly but this is not where I plan to finally rest.

    Where I was (wife suddenly passed away Feb 7 so I moved) I called the coop that handled us and I could do everything myself except the final step of connecting the system to the grid. Hence, my original question of doing it all myself up to the point of the actual grid tie. The master electrician can do that and the final inspector can sign off on it once he has done that and both of those is about 800 to 1k dollars.

    I wanted to say that when I last checked the pay back was local electrical rate + 8 cents per kwh for solar and much much less for wind and even less for hydro.
  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    Re: Questions about grid tie procedures.

    You might want to talk with the electrician--If you have to pay him $800+ , you may as well have him do some of the heavy lifting.

    I guess MLGW is:
    The Memphis Light, Gas and Water Division is a municipal public utility serving Memphis and Shelby County, Tennessee.

    Utilities+Government--A marriage made in .... somewhere ....

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DarkAlchemistDarkAlchemist Registered Users Posts: 12
    Re: Questions about grid tie procedures.
    BB. wrote: »
    You might want to talk with the electrician--If you have to pay him $800+ , you may as well have him do some of the heavy lifting.

    I guess MLGW is:



    Utilities+Government--A marriage made in .... somewhere ....

    -Bill
    That is the monopoly and 800 to 1k is the paperwork fees, inspector, and for his time but if he has to lift more than a finger at the box the costs can rise to 2500 dollars.

    You know I was scanning around the net and it seems in 2009 4kw residential home was the first here to give power directly to the grid and TVA paid them local residential rate + 12 cents and back then that was almost 20 cents per kwh they produced. Now I see my +8 cents is now the program is closed for 2013. WTH? Looks like they are not paying back anymore (like Australia is doing by end of 2014 by law) as of 2013. Well, it seems the man is fighting back and if batteries were not so expensive and constantly going up I would tell them all to stuff it up their ends and I would live off grid.

    I suspect more and more will cease paying or heaven help us if we end up like Spain where they are taxing people with solar because they want you on their state ran electric.
  • Eric LEric L Solar Expert Posts: 262 ✭✭
    Re: Questions about grid tie procedures.
    As far as where I live it is currently under the evil reign of MLGW where I can't have water and/or gas from them if I go off grid for electricity and codes dictate I am not allowed to have a private well for private consumption within the city limits (yes, they are crooked as it gets here and why I am leaving as soon as I can)

    Choose carefully where you move then. I just skimmed the Green Power Providers Program that MLGW runs with TVA, and even with the restrictions you mention it looks a lot better than many utility programs in the southeast. Even the possibility of a $1K utility rebate and $.09 per kwh generated, which I'm sure is above wholesale in your area, is way better than Alabama Power, e.g. (no rebate, .03-.05/kwh produced).

    The fact is that utility rebates and decent grid-tie agreements are disappearing; your utility isn't as bad as you seem to think.
  • DarkAlchemistDarkAlchemist Registered Users Posts: 12
    Re: Questions about grid tie procedures.
    Eric L wrote: »
    Choose carefully where you move then. I just skimmed the Green Power Providers Program that MLGW runs with TVA, and even with the restrictions you mention it looks a lot better than many utility programs in the southeast. Even the possibility of a $1K utility rebate and $.09 per kwh generated, which I'm sure is above wholesale in your area, is way better than Alabama Power, e.g. (no rebate, .03-.05/kwh produced).

    The fact is that utility rebates and decent grid-tie agreements are disappearing; your utility isn't as bad as you seem to think.
    TVA wasn't bad but they have shut down the program as of AUG 2013 because they have met their MW goal. It was really good what TVA used to do even at 8 cents over local rates but they have ceased now.

    As I said all over the world the grid is shutting down paying people and in Australia the old rate was 40 cents per kwh then in 2011 it went to 30 cents and those people who were promised 40 cents will now get 20 cents then in 2014 0 cents thanks to their govt. Broken promises by them and I see that happening here as the price per kwh goes down more people can afford solar which means more people expecting to be paid. The Australian govt used that as an excuse to pull out completely from paying anyone and it is happening over here. I suspect when those 36 cent per watt panels arrive in 2017 by 2019 the local electrical companies will have ceased paying and you don't pay you will not get from me so no grid tie. The only problem is that off grid is so expensive and in reality too expensive for most people.

    Basically the man has you and they know it.
  • Eric LEric L Solar Expert Posts: 262 ✭✭
    Re: Questions about grid tie procedures.

    You might consider a small battery-based system with a transfer switch at your house, and a low-voltage cut-off at the inverter which will switch your system over to the grid when the battery voltage falls below a set threshold. Then you maximize opportunity loads aggressively. That's what I have done with a 5.5 KW system with a smallish battery bank (17.5 kwh). Surplus power during the day is routed to heating (winter), air con (summer) and hot water heating.

    This summer, I've been averaging 16 kwh/day from my system, and buying an average of 4.5 kwh/day from the utility. Those 4.5 kwh are "expensive" in the sense that I have to pay the associated connection fees and taxes (so monthly bills are just under $30 for about 140 kwh of power), but cheap in the sense that they provide the power that I would have to make a big investment in more batteries, a larger inverter, generator and fuel and so on to provide myself (for prolonged cloudy periods, heavy loads like the electric range and dryer, etc.).

    If you do it this way you can probably do it all yourself without involving the utility; there's not likely much they can do about it as long as the transfer switch is up to code.
  • DarkAlchemistDarkAlchemist Registered Users Posts: 12
    Re: Questions about grid tie procedures.

    You know I was thinking about something like this but I couldn't figure out when I would use the battery side or the grid side. I know when my wife was alive we had 4 people living in a 70 foot x 16 foot mobile home and ran about 80-130 a month at 8 cents per kwh but with just me in this HUGE house (was once split into 4 apartments until the previous owner got caught then was reconverted back to a house) of my mothers with just a room AC and the fridge (a tad too warm in there by about 10 degrees f) I use 125 a month where the electric rate is more at about 9.5 cents per kwh and my family comes over and uses the stuff some days too but with natural gas being very expensive here and a gas water heater plus the water bill that really isn't all that bad (besides the ADMIN fee here is way more too). My figures are 6000 to 9000 watts of solar I could be 100% off grid at 4.5 hours of solar a day average.

    What kills the above is the cost of the batteries and they aren't never ending. When you consider Justin Case on youtube has 40kw of batteries and each battery is 12v 200ah at over 220 dollars a piece that is almost 2 of my complete bills. Now where I am going it gets even worse as their electrical rate is the lowest I have seen since before 1985 at only 4.5 cents per kwh.

    My real wish is that I could live off grid out in the boonies and to be left alone until my dieing day because I am tired of the govt and the pushing and prodding they are doing. I am literally about to explode and go postal but my sanity hasn't left me so I restrain myself but without my wife and what the govt is doing to people I really have to try hard not to.
  • solar_davesolar_dave Solar Expert Posts: 2,343 ✭✭✭✭
    Re: Questions about grid tie procedures.

    My wife and I talk about it too, but with our current setup we are getting pretty well cost independent. Nat Gas at about $17 a month (for 4 ish Therms the rest is overhead) and Electric on average about $40-$50 a month (low months in spring $0 from carry over pay out from previous year and worst case month about $150 for off peak night time AC usage and car charging), annually about $500. Going battery here is about impossible to meet the mid summer peak loads of 125 kWh a day. We could maybe reduce that to about 100 kWh a day with some additional conservation efforts but the low hanging fruit is all used up.

    One good thing is we can control our gasoline usage to nearly zero dollars if need be.
  • Eric LEric L Solar Expert Posts: 262 ✭✭
    Re: Questions about grid tie procedures.
    You know I was thinking about something like this but I couldn't figure out when I would use the battery side or the grid side.

    I measured my typical night time loads, and then sized the bank to support those loads at the winter solstice with no more than a 25% depth-of-discharge (so bank remained 75% charged). I picked the winter solstice since it's the longest period between the end of production one day and the start the next. I picked the 25% D.O.D. number since it's the most economical trade-off point between battery cycle life and use for deep-cycle batteries.

    The house switches to grid power when the batteries hit 75% state of charge. This keeps the batteries from being stressed and should improve their lifecycle. If there is heavy cloud cover, what typically happens is that the house runs on the batteries overnight from the day before, then the panels produce enough power the next day to support the house loads (even with the clouds they produce a few kwh) but, because of the clouds, there's not enough to recharge the batteries very far. So the next night, about 24 hours after the last full charge, it will go over to the grid. If the next day is also cloudy, it will go off grid during the day since there's almost always enough power from the panels to get the batteries up to the grid disconnect voltage and support the basic house loads, but since it was still cloudy and the batteries didn't get a full charge, it goes back on grid at night. This continues until sun conditions improve, but at my location I usually don't have to wait very long for a full charge.

    Notice though that even with a small bank and cloudy skies, I'm off-grid most of the time. When conditions are even partly sunny, I'm off grid all the time, except for a few large loads that are connected to the grid at all times (dryer, electric range, and a central heat pump that we don't use much).
    What kills the above is the cost of the batteries and they aren't never ending. When you consider Justin Case on youtube has 40kw of batteries and each battery is 12v 200ah at over 220 dollars a piece that is almost 2 of my complete bills.

    Those wouldn't be my first choice of battery type for that large a bank since he's forced to use multiple strings. I used a lower-voltage battery (6 volt L-16) and a single string and it was not very expensive sourced locally from a distributor. My bank is not even half the size of that guy's, but as I say I don't use much from the grid.
  • DarkAlchemistDarkAlchemist Registered Users Posts: 12
    Re: Questions about grid tie procedures.
    Eric L wrote: »
    ...The house switches to grid power when the batteries hit 75% state of charge.
    I asked Justin Case about this and he said "Well if you have 5 to 7 thousand Dollars for the controller then you need a (Selectronic SP Pro) Should do the trick. a switch is easier. Just search that on the web. " 5-7k? That is insane and I might as well go completely off grid at that price. What switch is automatic and will do like you said for unattended operation?
  • Eric LEric L Solar Expert Posts: 262 ✭✭
    Re: Questions about grid tie procedures.
    I asked Justin Case about this and he said "Well if you have 5 to 7 thousand Dollars for the controller then you need a (Selectronic SP Pro) Should do the trick. a switch is easier. Just search that on the web. " 5-7k? That is insane and I might as well go completely off grid at that price. What switch is automatic and will do like you said for unattended operation?

    No, nothing like that. Several inverter makes can be programmed to switch between grid and batteries depending on battery voltage. I use a Magnum MS-PAE model with the ARC controller, but the Ouback with the right Mate controller (Mate 2 maybe), some Schneider/Xantrex inverters, and likely other makes can do it as well. And it does it unattended, of course.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Questions about grid tie procedures.

    Will I regret asking "Who is 'Justin Case' (sounds like a fake name) and why should anyone listen to what he says?"
  • BB.BB. Super Moderators, Administrators Posts: 29,489 admin
    Re: Questions about grid tie procedures.

    "Just-In Case"??? ;)

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DarkAlchemistDarkAlchemist Registered Users Posts: 12
    Re: Questions about grid tie procedures.

    Youtube with a lot of videos describing his setup with the pluses and the minuses of his off grid system (yeah, he describes the bad along with the good for only a fool would say there are no bumps in the road with off grid).

    You really should watch Youtube more as he is one of the people everyone references.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Questions about grid tie procedures.
    Youtube with a lot of videos describing his setup with the pluses and the minuses of his off grid system (yeah, he describes the bad along with the good for only a fool would say there are no bumps in the road with off grid).

    You really should watch Youtube more as he is one of the people everyone references.

    No thanks.
    Too much nonsense on Youtube for my tastes.
  • DarkAlchemistDarkAlchemist Registered Users Posts: 12
    Re: Questions about grid tie procedures.
    No thanks.
    Too much nonsense on Youtube for my tastes.
    Each to their own as I prefer Youtube help videos over TV any time. I went from 109 hours a week of TV 22 years ago to 0-1 now.
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Questions about grid tie procedures.
    Each to their own as I prefer Youtube help videos over TV any time. I went from 109 hours a week of TV 22 years ago to 0-1 now.

    "Over TV".

    Um, yeah. Never thought of TV of being educational either, even when it was touted as such. I don't even believe the news these days.

    When it comes to technical advice, I'll stick with my own years of education and experience thanks.
  • NorthGuyNorthGuy Solar Expert Posts: 1,925 ✭✭
    Re: Questions about grid tie procedures.
    "Over TV".

    Um, yeah. Never thought of TV of being educational either, even when it was touted as such. I don't even believe the news these days.

    If you watch news, you can notice that many of them are taken from YouTube and then shown on TV.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Questions about grid tie procedures.
    The panels will be ground mounted so no permit is needed there.
    I hope you checked and are not just assuming that. It's not necessarily true and varies with where you are.
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