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Off grid feasibility

  • 03-11-2018 11:31pm
    #1
    Registered Users Posts: 861 ✭✭✭ homewardbound11
    Registered User


    Probably thinking out loud here .

    But is there any cost analysis of PV array with battery being backed up by a generator .

    Just thinking aloud of desiel costs and generator use to keep a battery array topped up for domestic use . Would there any economical benefit to not being on the grid


Comments

  • Posts: 0 [Deleted User]
    Combobulator


    It's not cost effective for a normal house. If you live in a temporary structure, miles from the nearest ESB pole or in a live-aboard vessel it's another matter.

    Modern li-ion batteries are too expensive to be viable for the scale required to have a week's autonomy. You can reduce your battery costs by at least ⅓ if you went with a traditional lead acid battery.

    Then there's the upkeep. Off-grid is not plug and play.


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,761 CMod ✭✭✭✭ unkel
    King Elon I


    Modern li-ion batteries are too expensive to be viable for the scale required to have a week's autonomy.

    A week is a very long time to have battery storage for. For sure that would be expensive to set up. Why are you suggesting a week, is that some sort of rule of thumb / generally accepted standard for off grid living?

    It would be far cheaper to have just a day or two of autonomy with the use of a genny as backup?

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    I am working for the past few months in designing an off grid system due to local constraints.
    No one can say that is feasible or not, here…
    I follow lots of forums where other people thinks to join or are living in a complete off-grid situation...and they are still enjoying life, with their wife ! :)

    My initial "today's" design that will give me a similar level of live comfort as now, involves:

    2 x 16 330W PV on a two tracker setup, with individual inverters
    80 tubes solar ,for a dual setup 2000l + 500l cylinder to store the extra heat, in water for DHW and for heating UFH
    batteries to compensate for 3 days of normal usage
    a 5kw vertical wind turbine to keep batteries happy
    a 5kw stand-by function diesel generator, soft start-stop and variable power
    Total cost around €12k and I am independent for whole remaining heart beat and life breath...

    I suggest to start with making the list of appliances needed for the comfort and then crunch those numbers related to hour, day, week, month, year.... is pointless to start from the PV or generator if you don't have the numbers correct.

    But to get here, i began with numbers, per appliance, per consumption, per hour of day, day of the week, week of the month, month of the year... you get the points and add some buffers, just in case.

    Lots of variables but from the comfort of my bed... mostly is "the state of your mind" in the first stage of "what can be wrong, can go wrong" or...can I use the hair dryer and the kettle at the same time !? What if I don't have lights today or heat tonight !? What if the fridge stop working for lack of electricity...what if the water pumps stops working and no water in the tank … and so on...
    All these questions have already answers given by humans...you just needs to be prepared to deal with and enjoy that situation.
    -LEDs rather than bulbs
    -fridge that works on 48V or normal 220v but with a ticker insulation, you can power off for 24 hours
    -some sort of ventilation with built-in heating that works on 24-48v battery system or off PV directly
    -very well and good fabric for the building, in relation to insulation and air-tightness
    -underfloor heating for heating
    -heat recovery ventilation to have a good healthy temperature across rooms
    -cooker that can work on electricity or gas
    All other basic foundation of a house (pumps for water, freezer to store food for long period of time and so on) can be programmed to work harder day time when is excess PVs and go in stand-by of odd during night time.

    More...if you need, ask please.

    Have fun...


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,761 CMod ✭✭✭✭ unkel
    King Elon I


    rolion wrote: »
    2 x 16 330W PV on a two tracker setup, with individual inverters
    80 tubes solar ,for a dual setup 2000l + 500l cylinder to store the extra heat, in water for DHW and for heating UFH
    batteries to compensate for 3 days of normal usage
    a 5kw vertical wind turbine to keep batteries happy
    a 5kw stand-by function diesel generator, soft start-stop and variable power
    Total cost around €12k

    Would you mind sharing your break down of that total cost of €12k? What batteries are included? I guess for 3 days of normal usage you would need at least 30kWh for an average Irish house (which uses 3.5MWh per year so about 10kWh per day - that's of course without any electric heating of DHW or UFH)? I'm not expecting much of a detailed answer from you BTW. You have a poor history of giving details about money. I'd love you to prove me wrong here though :)

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    unkel wrote: »
    Would you mind sharing your break down of that total cost of €12k? What batteries are included? I guess for 3 days of normal usage you would need at least 30kWh for an average Irish house (which uses 3.5MWh per year so about 10kWh per day - that's of course without any electric heating of DHW or UFH)? I'm not expecting much of a detailed answer from you BTW. You have a poor history of giving details about money. I'd love you to prove me wrong here though :)

    You will not get a breakdown from me...you have answered your own question..
    Not getting in same time waste as the gas vs electricity war...you prove I'm wrong designing a typical Irish house demands when talking about a fcuking non typical Irish house on an offgrid topic ... ;)
    Happy Monday.


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  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    Anyone wants to discuss off-gridd_ing / away of the system !?
    I advise to begin H E R E ! :)
    Be good...


  • Posts: 0 [Deleted User]
    Combobulator


    unkel wrote: »
    A week is a very long time to have battery storage for. For sure that would be expensive to set up. Why are you suggesting a week, is that some sort of rule of thumb / generally accepted standard for off grid living?

    Generally yes. Who complains about too much energy?
    I run deep discharge cycles between a week and a month with micro-cycling on my 5year old, flooded lead acid golf cart battery, that I tested yesterday as good as new, what cost me €300 for 2.8kWh.

    Law of averages; when you have multiple intermittent generators it's easier aim for a week than a day. 4 days with sun = enough for 7 days.
    It is expensive building and maintaining your own services will never be as cheap as accepting three wires from the ESB.
    It has other benefits.

    A forklift battery will suffice, no need for high energy density expensive wall mountable battery tech.


  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    @unkel
    Was thinking when my Leaf's battery goes at a level that is not sustainable anymore to keep the car driving it can be "removed" and adapted to work with a minimum investment and for a minimal demand in the house,mostly lights,life support and water.

    @Liam
    Probable the needs of one post here does not characterise the needs of the off-grid demands.
    You will prioritise what you need in "case of" and work from there,all the way up to "life support" ?
    I can stay without audio/video/IT for a day or two ,even few nights but not without lights,heat and water...
    I'll share when i know more...


  • Registered Users Posts: 16,233 ✭✭✭✭ Sleeper12
    Registered User


    Just thinking aloud of desiel costs and generator use to keep a battery array topped up for domestic use . Would there any economical benefit to not being on the grid

    Have a look on YouTube. Plenty of people living off grid posting regular videos. Even in countries with all year round sun they struggle & do without a lot of "luxuries" that we call necessities.


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 59,761 CMod ✭✭✭✭ unkel
    King Elon I


    rolion wrote: »
    @unkel
    Was thinking when my Leaf's battery goes at a level that is not sustainable anymore to keep the car driving it can be "removed" and adapted to work with a minimum investment and for a minimal demand in the house,mostly lights,life support and water.

    For sure, their is a whole new second life for a Li-ion battery after the car is a write off / end of life or if the range is no longer enough for your needs. It will be able to do a lot more than just minimal demand too. After about 15 years the usable capacity will probably have gone down from 22kWh to maybe about half that.

    I wouldn't think taking the battery out of your Leaf and attaching it to your home is something your average DIY person installing a few solar panels will be able to handle though :)

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



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  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    unkel wrote: »
    :)

    For an offgrid situation / setup, i will say the most important thing is the mindset, the correct mind set...a very healthy menthality of the person or the couple deciding to go to that deep away fron "normal" level,away from the concrete,glass,noise and daily loads,well, i will call the first step completed.

    Not lastly,not very rellevant as a DiY skill is the respect for others and respect yourself. Sometime,your right mindset can save you from a very peculliar situation while other times,you will need to rely on other people reciprocal help,"i scratch your back, you do mine". So, being arrogant and offending without any facts can bring the off-grif person in a deeper off mood,risking his life and partner's too.

    As a technical logic massive chaneg over challenge,here on-grid wife was using the cooker ,hover and ironing at the same time...There,you will have to watch the meter and serialise them,one after the other...as there time is not running at all...no pressure to get the kids at school,to get ready for work now otherwise you will encounter the morning traffic or that you need to cook or get food from the shop...

    In meantime, to let you dream about off-grid feelings,i gift you with a look at the below place and think about car noises and traffic increased every month (now is almost 90 minutes),concrete,glass,metal,bills and regulations,massmedia with their agenda,people / neighbours with their own ... while there, will I worry about board's posting skill set assesments and challenges !? Dont think so... is going to be a stresful silence... :)


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