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  • Sergeant
    Junior Member
    • Mar 2010
    • 12

    #16
    Originally posted by Mike90250
    Grid-Tie vs Off-Grid

    If you only have a few, spotty outages from your electric company, you really want to go Grid Tie. You need a building permit anyway, and just need Utility to sign off. Most utilities in larger cities have established plans. More Rural areas are sometimes more difficult, but generally, not impossible. You use the electric company as your nighttime battery. If a power failure happens, ride it out with a cheap $500 generator you bought by not buying $5,000 worth of batteries.

    If you annually, have regional ice storms that take out power for days/weeks at a time, then it's worth a battery backup/grid tie. Your house keeps running if the neighborhood shuts down. 1 backup generator, 2KW. Costs more, and less efficient, but useful.

    If you cannot get power to your property, and have to go off grid (like me) electric will cost you 5x as much as buying it from the electric company. And battery replacement costs every 7 years. And 2 backup generators. And meticulous maintainance to keep it reliable 24/7

    I may have mis-read your actual monthly usage. Wow! You need to look into conserving a lot of energy. I think you can see that there is a big cap, and conserving is less expensive than installing a lot of PV. 2,986KWh is a LOT of power.
    I have a generator for small outages...that's not an issue. Why do I need a permit though? I live outside the city and own my own home and land. I never have had to have any permits. I'm not sure why the great power usage...my heat and a/c unit are kept off during the day and turned on only at night. Would it be possible to set it up where it's off grid during the day and. Let the sun power my frig during the day and switch to grid during the evenings when we're at the house? I already have a separate input that I use to power my house with my generator during power outages .

    Comment

    • Mike90250
      Moderator
      • May 2009
      • 16020

      #17
      Any human inhabited house in the USA, is regulated by county/city building code, unless it's on the national historic register. You cannot alter the structure or increase room size without a permit. Or you are breaking the law. Some sort of admin law, that exists to extract money from people with the nerve to build. I had to get a county permit, and an engineering approval, for the 12' pole to hold my solar array. The pole mount was certified by it's mfg, but the county needed a engineer (for $250) to tell me to auger a 24"w 10'd hole for the pole and fill it with rebar & concrete. Or they can make you take it apart and show the wires inside your wall are done properly.
      But that's the rules. Electric company in my area will only install poles and wires to a permitted structure. So I could not even get power to my gatehouse.
      So vote some different county officials in that write rules your way.
      Powerfab top of pole PV mount (2) | 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

      solar: http://tinyurl.com/LMR-Solar
      gen: http://tinyurl.com/LMR-Lister

      Comment

      • Sergeant
        Junior Member
        • Mar 2010
        • 12

        #18
        Originally posted by Sunking
        Sergent first thing is if you have grid power available, you do not even want to consider going off-grid with a battery system. The reason is simple, if you go in with a battery system you will be paying 5 to 30 times more for electricity than you do now buying it from the electric company. There are a few rare cases where going off grid can ever pay off as it takes some very special circumstances like living like a hermit and a recluse.

        Now before you even consider going grid tied or off-grid, the very first step is a complete remodel of your home, upgrading all appliances, lighting, and all mechanical systems in addition to life style changes. For every dollar you spend on upgrades will save you 2 dollars on the solar PV install

        Upgrades mean replace all windows and doors, add insulated siding, insulation in attic and crawl spaces. Replacing Air Conditioning with highly efficient dual fuel heat pumps. Getting rid of all electric hot water heaters and cooking and use either LP or NG, replace all fixed lighting fixtures with fluorescent and all bulbs with CFL. Finally upgrade your refrigerator.

        Once you get all that done first, you may find out you do not need solar PV, and if you do, well you just cut the cost down by 50% or more. The upgrades to your home are equity positive meaning the value of your home goes up more than what you put into it. Solar PV in all states except states like CA and AZ is net negative.
        Makes sense. Thank you.

        Comment

        • Sergeant
          Junior Member
          • Mar 2010
          • 12

          #19
          Originally posted by Mike90250
          Any human inhabited house in the USA, is regulated by county/city building code, unless it's on the national historic register. You cannot alter the structure or increase room size without a permit. Or you are breaking the law. Some sort of admin law, that exists to extract money from people with the nerve to build. I had to get a county permit, and an engineering approval, for the 12' pole to hold my solar array. The pole mount was certified by it's mfg, but the county needed a engineer (for $250) to tell me to auger a 24"w 10'd hole for the pole and fill it with rebar & concrete. Or they can make you take it apart and show the wires inside your wall are done properly.
          But that's the rules. Electric company in my area will only install poles and wires to a permitted structure. So I could not even get power to my gatehouse.
          So vote some different county officials in that write rules your way.
          HuH!!! Sounds like it's going to be more trouble than it's worth, for me to continue in this direction...I thought the Sun would be able to produce more energy than this.

          Comment

          • jlowell
            Junior Member
            • Mar 2010
            • 1

            #20
            Originally posted by Sergeant
            HuH!!! Sounds like it's going to be more trouble than it's worth, for me to continue in this direction...I thought the Sun would be able to produce more energy than this.
            Sarge.....as of 3 or 4 months ago Texas started doing some very minor inspections outside of city limits...they are minimal and mostly pertain to new structures and septic systems.

            I am a homebuilder in Houston and of course in the city we have extensive inspections. In the county for new structures there are now 4 inspections.

            In your case I doubt you would need it. Just ask. It is no big deal and won't open up a can of worms to inquire. I am building myself a place in the country and it is a relief not having to deal with the building bureaucracy for once.

            Your problems lie elsewhere from what I read...(and I am a newb at this).......sounds like you need to get your power consumption down as Mike or one of the other pros said.

            cheers,

            jim

            Comment

            • Sergeant
              Junior Member
              • Mar 2010
              • 12

              #21
              Originally posted by jlowell
              Sarge.....as of 3 or 4 months ago Texas started doing some very minor inspections outside of city limits...they are minimal and mostly pertain to new structures and septic systems.

              I am a homebuilder in Houston and of course in the city we have extensive inspections. In the county for new structures there are now 4 inspections.

              In your case I doubt you would need it. Just ask. It is no big deal and won't open up a can of worms to inquire. I am building myself a place in the country and it is a relief not having to deal with the building bureaucracy for once.

              Your problems lie elsewhere from what I read...(and I am a newb at this).......sounds like you need to get your power consumption down as Mike or one of the other pros said.

              cheers,

              jim
              Sure, the inspection is not a problem, but my co-op requires producers/homeowners to produce a $1,000,000.00 insurance policy if they are going on-grid with their system...kind of defeats the purpose if a person is installing a solar system to save money when they have to spend more in insurance premiums to even have it. It would be neat to know a way around this...any thoughts???

              Comment

              • lile001
                Solar Fanatic
                • Feb 2010
                • 105

                #22
                Originally posted by Mike90250
                1800 x .8 (a 20% loss in power from being heated by the sun) = 1440

                1440 x 5 hours = 7,200Wh per day

                7.2 KWh x 30 days = 216KWh per month expected harvest, with perfect sun angle


                So, installing a Grid Tie (no batteries, just PV and Inverter) system, looks like it could make a big dent in your electric bill, with a yearly average net meter program. If you add batteries, you increase the cost a fair amount, increase maintainaince, and decrease efficiency a bit.

                If you can take and input your roof direction and pitch (angle) into the PV watts website, for your area, you will get a much better, climate adjusted (cloud cover) estimate for your area.

                http://www.pvwatts.org/
                Translation: with grid tie, you don't have to have a solar array that matches your usage. Anything you do helps lower the bill. While it would be fun to shut off the power company ("Take that, you heartless capitalists!") it might be better to join them and sell power to them. If you can offset a third or half of your juice, then you are fighting the good fight.
                Lawrence Lile, PE

                Comment

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