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Can powerwall be setup for off grid with natural gas backup?

Discussion in 'Tesla Energy' started by rmay635703, Nov 25, 2015.

  1. rmay635703

    rmay635703 New Member

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    Somewhere In, WI
    I have been ready my whole life to live off grid and my sub $8 a month electric bill (not including the $20+ of fees) goes to show I am ready.
    I find it odd that people have trouble reducing their electric consumption, it was the easiest part, just means a different TV, PC and lighting use, along with natural gas powered appliances (dryer,water heater,stove)
    no different than what my depression era grandmother would have done, if you aren't using it unplug.

    Anyway

    My question is a simple one

    Powerwall is setup to be a grid tie setup.

    What would I need to make it tie into and control a natural gas inverter, while being FULLY off grid?
    (that can sync up to another AC source if needed)

    My idea is a simple one I have always had, and I already have some lithium, a small solar panel, electric car, and a 2kw genset that can be setup for remote electric start and natural gas. Originally I thought of just DIY and getting the grid connection cut.

    In my area natural gas produced electricity at home is cheaper (long term) than buying electricity off the tap,
    it also allows for some level of at home co-generation (even better)
    because it does get awefull cold and some of the heat from the motor can be diverted to add some heat to the house while also recharging the battery source.

    So if my mind I would need a controller that would kick in the genset when the battery was below some pre-set level, say 50% and then recharge the battery up.
    To do this would require
    1. A way to charge the powerwall from 110vac
    2. A controller to turn the genset on and off based on battery SOC and obviously loads

    I never use more than 3kw of energy even when I have all sorts of things going on in the house and could easily keep myself from overloading the system.
    My TV is efficient, my lights are all LED, my fridge is efficient and my EV doesn't draw over 1200 watts, amazing what I can do on 10 watts now days.
    The only sticking point is hair dryer use but given the fact that I don't charge the car and run the hair dryer (thank you 1930s wiring and popping the breaker) I can easily adapt to that limitation with some simple common sense.

    So any suggestions?

    Also there was talk of a $3000 price point, what can the powerwall do out of the box? besides of coarse just be a battery.

    Thanx
    Ryan
     
  2. Ampster

    Ampster Member

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    #2 Ampster, Nov 25, 2015
    Last edited: Nov 25, 2015
    Powerwall is a battery. Most of the functionality you are asking about would be delivered by the inverter.

    To charge a PowerWall off 110v you would need a 400v DC charger or a power supply that would provide 350-400 volts DC. You would also need a high voltage cutoff relay set up to shut off at the correct voltage.
     
  3. rmay635703

    rmay635703 New Member

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    ?? So the powerwall has absolutely no functionality built in at all?I thought it would at least come with some sort of management system?If that is the case I can still DIY for less at the same reliability, how does tesla package these systems?What usually has to be bought and what type of equipment do they usually bundle?
     
  4. stopcrazypp

    stopcrazypp Well-Known Member

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    #4 stopcrazypp, Nov 27, 2015
    Last edited: Nov 27, 2015
    Why don't you look at the page itself?
    https://www.teslamotors.com/POWERWALL

    It has a pretty clear diagram that shows how it ties into a solar panel system and says clearly it does not include a DC-AC inverter. It does not say anything about a AC-DC inverter either (which you would need to charge from your 110VAC source), and it appears to not include it.

    The two companies that are working on compatible inverters is SolarEdge and Fronius.
    You may want to look at Solaredge which already has datasheets on their Powerwall compatible products:
    http://www.solaredge.us/groups/us/products/storedge

    It is not currently intended for off-grid applications with generator, but rather used with solar panels.

    What it does have is a BMS and liquid cooling (so you don't have to worry about battery management, it's largely just a black box that takes in and outputs 350-450VDC, although there are some battery control lines looking at the StorEdge datasheets).

    This thread may also be of use:
    http://www.teslamotorsclub.com/showthread.php/48989-SolarEdge%C2%92s-StorEdge%C2%99-DC-coupled-storage-solution-allows-home-owners-to-maximize-self
     
  5. Ampster

    Ampster Member

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    As pointed out above, it does have a battery management system which might be able to control a charger. Yes, you might be able to DIY for less using Volt, Leaf or Tesla packs from wrecked cars. As far as reliability and integration on the DC buss, we don't know yet. Time will tell.
     
  6. EVSteve

    EVSteve 110% Solar Powered

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    I hope it does work without being grid tied using solar panels. I've had an ongoing issue with the local utility for the last few years. Despite numerous complaints they can't get their voltage coming in to stay below the Pennsylvania requirement of 252v. They keep pushing things up to 255v incoming at times causing my solar inverters to shutdown due to over voltage. It claims a lot of power production especially in the winter. Every time they shutdown they idle for 5 minutes then try again. Powerwall was my solution to get off the grid not only to stop using carbon sources at night through net metering but also to maximize the use of my panels.
     
  7. Cosmacelf

    Cosmacelf Active Member

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    Do note that Powerwall is still vaporware at this point. as are the compatible inverters which are necessary for its use in a working system. I'm not sure why Tesla keeps announcing things with delivery dates that keep slipping, but they do.
     
  8. EVSteve

    EVSteve 110% Solar Powered

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    Compatible inverters arw vaporware? We have SolarEdge inverters. On their website are the components combined with a firmware update that make the connections possible. Are you claiming SolarEdge has been listing equipment they haven't produced? Cause I have 3 of them sitting in my backyard.
     
  9. nwdiver

    nwdiver Active Member

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    Well... the 'off-grid' aspect is 'vaporware'; There are no SolarEdge inverters capable of operating without the grid as far as I'm aware.
     
  10. jeffhre

    jeffhre Member

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    "I find it odd that people have trouble reducing their electric consumption, it was the easiest part, just means a different TV, PC and lighting use, along with natural gas powered appliances (dryer,water heater,stove)"

    LOL, not so easy w/o turning to NG. I'm trying to wean myself from fossil fuels, not just use less electricity!
     
  11. EVSteve

    EVSteve 110% Solar Powered

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    All grid tied inverters are technically capable of operating off grid. All that is needed is a AC coupling setup that fools the inverter into thinking grid power is being supplied. Lots of companies have been doing this for a while now.
     
  12. Cosmacelf

    Cosmacelf Active Member

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    Afaik the solar edge firmware is not shipping yet, so you cannot, today, buy a power wall compatible inverter.
     
  13. rmay635703

    rmay635703 New Member

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    For me the main thing I need is reliable battery management so the powerwall would get me 90% to where I have to be, I can run a variety of voltages and rectify AC if needed but controls will be crude.

    Also AC inverters in my experience are a very weak link, especially when talking something other than low voltage DC to AC.

    Our area is 100% coal (well almost), in my case my goal is to use the least ENERGY the most efficiently,
    I could care less what form it is in if it all comes from fossil fuels.
    Gas water heaters (if you have the right one) are more efficient round trip than electric ones considering my local electric source mix.
    Gas cogeneration (home level electricity) is more efficient than traditional electric (not counting geo thermal which is impossible in this town)

    Last month my gas bill was $5 and my electric bill was $7, this will change by a factor or two once I get this months bill but still, I don't think its too bad.
    Summer I tend to be under $3 a month on both.

    In my mind,
    Use whatever form of energy is most efficient and the least expensive to get the job done.

    Foolish to do otherwise and yes I would love to go solar but its not feasible when you have a 1/12 of an acre in Wisconsin by trees and other nuisance objects. But I do have about 60 watts of solar :0
     
  14. EVSteve

    EVSteve 110% Solar Powered

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    Why is geo impossible in your town? Using a ground source heat pump with a desuperheater would be better than gas imo. Any way I can reduce the risk of CO entering the house I'll take. The way the gas is produced plus the explosion possibility makes gas a no go for our house.
     
  15. rmay635703

    rmay635703 New Member

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    My 1/12 of an acre lot is unbuildable and non-conforming, you can draw into that what you want but the likelyhood of geo thermal with the regulations and setback on a super small lot is basically zero, if I were to touch this house in any way I would be totally screwed.This areas goal is to condem and eliminate all the little 100+ year old properties and merge them into larger lots, obviously if you want to spend $250,000 on legal expenses on a $16,000 house anything is possible but I rather not go that route.To me if I can get my average utility bill including fees below $30 a month I've won, that is only possible if I break the grid connection, you can feel great about being gas free but if your using 1000+ KW hour equivalent of energy and I'm using 120KW a month (converting gas energy to electric) a month I think I've won.Ah well.
     
  16. jscholl

    jscholl Member

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    Obviously I don't know your situation, but I'd be careful about going off-grid. I saw someone on here mention a case where a woman used solar panels and batteries to totally disconnect from the grid, and because of that her house was condemned as unlivable. As I said, I really do not know your situation at all, but if your house is in danger of being declared unlivable anyways, I would suggest being cautious. That being said, you do you.
     
  17. GSP

    GSP Member

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    Can power wall be setup for off grid with natural gas backup?

    Anyone interested in this sort of thing should check our Homepower magazine. They have tips for how to design and build your own off grid system, or how to pick a good installer to do it for you.

    GSP

    Renewable Energy Efficiency Technologies | Home Power Magazine
     

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