A 10-step guide to going off grid - from your utility | RenewEconomy

A 10-step guide to going off grid – from your utility

Ergon Energy provides guide to households considering using solar and battery storage to quit the grid. It says it doesn’t want to scare customers into staying with them, but there are 10 things people should consider first.


Last year, a CSIRO study confirmed that up to one-third of all consumers may wish to quit the grid altogether if presented with the right technology, and they get tired of the way they are treated by the grid-based utilities.

Many downplay the idea, describing such decisions as “irrational” and “uneconomic”, and seek to convince consumers to stay on the grid, sometimes with scare campaigns about the cost of leaving. One utility, however, has decided to address the issue in a different way, and published a 10-step guide for consumers considering the idea.

foyster off grid
David Foyster

Ergon Energy doubles as the main network operator and retailer in Queensland – apart from the south-east corner – and because it services regional and sometimes remote areas, is likely to be at the forefront of the move to quit the grid. In fact, it predicted as much in its annual report several years ago.

“With reducing costs for solar PV/battery systems and a rise in off-grid enabled products on the market, many more people are considering making the switch,” the company notes in its newly posted off-grid briefing for consumers.

“We’re here to support you in any decision you make about your energy future. So, if you’re thinking of going off-grid one day, we want to ensure you’re well informed before you spend any money.”

The principal author of the report, Dean Comber, Ergon’s product manager for customer inverter systems, says it is about providing consumers with “choice and control”, and this involves solar PV, battery storage and home energy management systems.

“We appreciate there is a small and growing number of customers who wish to exercise choice and control by buying and managing their own electricity generation and storage system and disconnecting their premises from the grid,” Comber told RenewEconomy in an emailed statement.

“Based on our insights from our research, the media, and informal discussions with customers and intermediaries such as the PV and storage industry, we want to ensure aspiring grid-disconnectors have an understanding of the realities of living with a stand-alone system.

“As you know, once they buy their Tesla or other battery system, disconnecting from the grid may seem an easy next step, in theory, but it’s not the same for every customer and there are many technical or cost differences between grid-connected and stand-alone battery systems.”

The Ergon approach is a softer one than that adopted by the main networks lobby, which last year published assessments that put the cost at disconnecting at around $72,000 a home. That may be the case for some, but not for all.

Comber, in an email to colleagues in other networks a few weeks ago, said Ergon was seeking to highlight the realities of leaving the grid, “without looking like a big corporate entity trying to scare customers into staying with us.”

In his statement to RenewEconomy, Comber says that Ergon recognises that a “positive outcome” is certainly possible for those “grid-disconnectors” who have energy-efficient homes and lifestyles, who are willing and able to maintain their stand-alone systems, and who are prepared to make lifestyle adjustments if necessary to live within their energy means.

“We also know that some may simply be prepared to make more significant investments in larger systems to meet their energy use patterns.”

The key motivation, he says, is to minimise bad outcomes for customers who want to disconnect, but find that it is not such a great idea for them. Those bad outcomes include having oversized systems, still facing standing charges, or just finding the whole experience terribly inconvenient.

The issue about leaving the grid is particularly important because so many consumers are looking to battery storage, particularly with feed-in tariffs low and many in some states losing the premium tariffs that they have enjoyed in recent years.

But, installers note, there is a large degree of misunderstanding about what battery storage can achieve, and what different technologies are best applied for households depending on their need.

Others suggest that consumers may jot be getting good advice because of the sales-driven process of some vendors. And there are also concerns about quality and safety standards.

“Early feedback on our new web page about going off-grid is that many people have had their eyes opened to the challenges of living off the grid,” Ergon says.

“We also hope that the PV industry will view this web page as a resource to help educate their potential customers and manage their potentially unrealistic expectations before investing time that may prove to be wasted.”

So, what are the ten things that consumers should think about before going off grid? Here is a summary:

1. Payback on your investment

To determine your payback period on a solar PV/battery system, here are some things you should consider:

  • The purchase price
  • Solar panel capacity required
  • Usable battery capacity required
  • System maintenance costs
  • The loss of an existing feed-in tariff
  • The future price of electricity (will it go up or down, and by how much?)
  • Your electricity usage – both your daily peak demand and your total use in an average week.

You should also consider if you’ll stay in your home long enough to recover your costs. Discuss your ideas with a number of solar PV/battery suppliers to see what options they suggest.

2. Roof space for solar panels

Considering your daily electricity use, is there enough of your roof in the sun for the amount of panels you’ll need? If you don’t have enough roof space, you may need to mount panels on your shed or even on the ground. This could come with further set-up costs.

3. Back-up power generation

Having an off-grid electricity system means thinking about the right size generation and storage to get you through your peak daily needs. Also through any time there is a run of cloudy days. Your solar PV/battery system won’t supply power if:

  • The battery has been fully used at night-time and needs charging
  • There is a system fault or breakage
  • It is undergoing scheduled maintenance.

If you can’t do without power at those times, you’ll need a back-up generator to meet your basic electricity needs. A generator must be housed somewhere safe with appropriate ventilation and not cause a disturbance (eg. noise and smell). Generators will run best when maintained regularly and refuelled. Read more about generator safety and use

4. Spikes in your power use

Your electricity use varies greatly within a day, with regular high spikes of demand for very short times. Air conditioners and pool pumps can create short bursts of high demand when starting, often only lasting a few seconds.

An off-grid system’s inverter must be able to supply this high start-up power or the appliance may not start properly. This demand is additional to other electricity loads running at the same time, for example the TV, fridge, computer, etc.

If your inverter cannot supply these high spikes in demand, you may have to give up some non-essential appliances, or use them less and more carefully. Otherwise, you may have to install a larger system at a higher cost.

5. Lifestyle changes

Going off-grid usually requires some lifestyle changes, depending on the type of appliances you have and your electricity demand.

Energy saving habits and energy efficient appliances will help to prevent your system cutting out or not having enough power to run your home. Also, you can consider the impacts of:

  • Having house guests
  • A particularly cold winter or hot summer
  • Hosting a party.

Would your chosen size of system cope?

6. Battery safety risks

All battery types have risks including explosion, fire and chemical leakage. To keep you, your family and your neighbours safe, ensure your batteries are:

  • Installed correctly
  • Stored safely (think of closeness to living spaces, exit paths and potential damage to your home and car)
  • Regularly maintained.

There are regulations governing the housing of batteries that could add to your purchase costs. Read more on our battery safety webpage and the Clean Energy Council website.

7. Ongoing costs

Solar panels generally have 20 – 25 year performance and operating warranties. Inverters and battery management systems may only have a five or 10 year warranty. This means you’ll probably need to replace inverters and batteries at least once, perhaps twice, during the life of your solar panels.

If your system breaks down, it could be quite costly to fix. And with no electricity supply from the grid, you’ll have to pay for fuel to run your generator.

You may also have to pay someone to clean your panels, check your system (ideally annually) and service your generator.

8. System maintenance

When you go off the grid, maintaining your power supply becomes your responsibility. Regular services by an electrical professional are essential.

Minor issues could be inconvenient or possibly result in you using your back-up generator for quite some time. It depends on the level of system support, so some important questions for a potential supplier or installer include:

  • How is the product supported?
  • Is there someone to call early in the morning or at night for assistance?
  • How long might it take spares to come, considering they may need to come from another country?

9. Charging an electric vehicle

If you have an electric vehicle (EV) or are considering buying one, charging it creates a high electricity demand. Meeting that extra demand may add a lot to your solar PV/battery set-up costs and the roof space required for panels. The average EV draws around 18kWh of charge to travel 100km*.

10. Your property value

An off-grid home may draw in some potential buyers and deter others, so if going off-grid is appealing to you, consider the following:

  • The potential buying pool could be smaller when you come to sell your home
  • Even if a buyer is prepared to pay more for an off-grid house, that amount may be less than the total amount of the payback you expected
  • As well, check with your home insurer to ensure your home remains suitably insured.

Also, it’s a good idea to check any local council restrictions or estate covenants.  These can include restrictions on solar panels on the front of houses, where the batteries are housed and the use of petrol/diesel generators – particularly at night given the potential noise levels.

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  1. Finn Peacock 4 years ago

    I think that is a great approach by Ergon. Good on them. Bit late though? The discussion seems to have moved on from everyone clamouring to get off the grid with grid connect + storage going mainstream? People seem to appreciate that the grid had a lot of value as a backup.

    • Gyrogordini 4 years ago

      Finn, I suggest that for many city and rural folk, staying connected is the lessor of two evils. By all means, reduce consumption to the max, and monitor ins and outs, but my preference is “dependent (connected) self-sustainability”

    • Ian 4 years ago

      Finn, you’re a man with a lot of influence, perhaps the following concept may be of use to you. : home battery storage has two functions 1. Time shifting day time solar production to night time energy use -daily cycling requirement. 2. Standby function. Storage needed for days of poor solar resource. A daily cycling battery need not be large it only needs to cover a relatively small night time use of electricity 7 KWH should be quite adequate. The standby function, is another kettle of fish, it needs to cover the whole day’s energy requirement and several other contiguous days requirements too , 70 KWH may be required, and the times that this would be used maybe only once or twice a year. This is the point where the utilities laugh with glee . Realistically a standby FF generator is needed, or some other work around.

      • Mike Dill 4 years ago

        I am researching a V2G solution for those few days when the sun does not shine for a few days in a row. My EV has plenty of battery to run my house for a day, and I can charge elsewhere, even if it gets expensive.

  2. Chris Fraser 4 years ago

    Even before considering this list, I don’t think I can go off. Your house could possibly go off, if you have reasonable thermal performance (mass and insulation). By swapping out gas and installing modern appliances and gadgets, my consumption is actually going up ! And not even an EV in sight.

  3. Peter Bulanyi 4 years ago

    Did I miss something? The critical issue of life cycle and replacement cost of batteries was not mentioned. This is most important when having this particular conversation with grid-disconnect clients to ensure there is no misunderstanding.

    • Peter Bulanyi 4 years ago

      Oops! Apologies, mention of battery replacement cost is there in Point 7, paragraph 1, although I believe it should be a headline item in itself especially with large off-grid battery banks in the $10k plus range. Inverter replacement can be covered off by household insurance policies post warranty, PV modules can last well beyond 25 years if they are of good quality, but battery replacement costs needs particular highlighting as I can’t see a way around it except mitigation via the expected but yet undefined reduction in battery costs into the future.

      • solarguy 4 years ago

        Peter, Large battery banks cost much more than $10k.

        • Peter Bulanyi 4 years ago

          For sure, I originally wrote $10k – $100k then changed it to “plus”. We just installed a 100kWh Li-Ion battery bank with a cost of Euro80k. For that one we have to air-condition the battery room otherwise the warranty is at risk. Temperature is such an issue with batteries, but easily overlooked too.

  4. Alan S 4 years ago

    Of course there isn’t a single answer that suits all cases:

    If you’re on the old FiT that here in SA will apply to 2028 you’d be financially better off staying as is – on grid with no battery.

    For those on the reduced FiT who currently schedule their electricity use for when their system is generating it may be sensible to install a small battery system and stay connected. Get an inverter that isolates from the grid when there’s a blackout to keep the lights and fridge going.

    If you’re an early adopter like those who paid $20k for a 1 kW system 15 years ago and want to reduce grid-dependence you might want to get batteries and go off. However get some independent advice, do your sums and wait a couple of years for battery prices to drop. There’s a good case for staying on grid and minimising use.


  5. FaulcoPete 4 years ago

    I don’t see any mention here of what I consider to be the most egregious action of the incumbent power industry, viz the sly and persistent change in the billing methodology whereby fixed charges rise and usage rate falls or remains flat. They don’t give a toss if an environmentally aware customer instigates efficiency measures and/or installs a renewable energy system; they’ll get you via fixed charges and you are powerless to stop that unless you disconnect. This is the hand that we are dealt with, due to that industry’s greed and environmental disinterest. Customer response is then driven partly by irritation, or downright anger, and the stay-or-disconnect option then is more than just a financial decision.

    • Ian 4 years ago

      Faulcopete you are right of course , but Ergon’s advice expressed in this article is faultless.

      It may be helpful to look at the storage requirement as being of two types.1. Is the daily cycling of batteries to time shift solar energy production to night time use. 2. The standby function to cover days of poor solar resource. Day time cycling needs only the common 5 to 7 KWH battery system. The standby storage needs to cover several days of total daily energy usage probably 10 to 15 times the daily cycling requirement. Unfortunately the network operators offer a much cheaper standby option even with their fixed fees etc., again, very unfortunately a network connection is thus still required for all practical purposes. You now have the situation where you need a network connection and have to pay for it, the daily cycling function of a small battery system might save the few self generated KWH but comes at a substantial price $10 000 to buy a 7 KWH storage system to save maybe $1 or $2 a day. You have to be really P!ssed off with the utilities to spend so much money to save so little or live in a remote location where the off grid option starts to look more attractive. The other issue is the total rort of the battery suppliers. Lithium batteries wholesale are approaching $150/KWH to the EV market yet are over $1000/ KWH to the home battery market. This makes the utilities look like saints in my opinion.

  6. hugh spencer 4 years ago

    As one who has been living remote “off grid” for 28 years (there’s no grid up here) I would agree that having to manage one’s own electrical consumption demands a substantial shift in behaviour and awareness. We have quite a big system – most of it cobbled together over the years. Central to managing it is having a prominently mounted Amp-Hour meter (Trimetric 2020) which gets looked at many times a day – it is our “fuel gauge” (and allows us to detect when things go wrong (rat’s chomped through a cable – breaker has thrown etc) and fix it. If you have lead acid batteries (only get good AGM cells) they must seldom if ever be discharged by more than 30% of their capacity – if you want the batteries to be around for a long time, this is where the Amp-Hour meter is critical (and this restriction must be taken into consideration when sizing your system – 900AH battery bank is really only 300AH). Always use maximum power point charge controllers (MPPT) – as they can boost the effective output of your panels on grey days by up to 30% (and reduce panel wiring costs). If you can – have a spare inverter, charger and controller -so if one goes down – you are not stuck. I’d be very leery of some of the “all in one inverter-charger-controller” – if any component fails – you are out the lot. And if it’s really lousy weather – go do something useful outside! And yes – the new evacuated tube solar HWS – are fantastic – and unless you are hot water hogs, you probably will never need to boost them. And read up all you can on solar stand alone power.

    • solarguy 4 years ago

      Hello Hugh, I have to say that the only thing as a professional designer & installer is that most AGM batteries are crap. You didn’t mean Deep Cycle lead acid gels like BAE etc, did you? Those can give over 4000 cycles down to 40% DOD. That’s 11 years life! Of course 30% DOD will give max life, say 15yrs.

      • hugh spencer 4 years ago

        You are probably right – we use Sonnenschein A602/960 – (24V system) – they seem to be the top of the range – we’ve had them for10 years – and they are holding up well (I need to re-check conductances) – we did have Sungel 2SG1000 and they failed (plate swelling and cracked cases). However, this may make you cringe, we have developed a desulphator which really works – it doubled the Sungel life (though the control and test cells still burst) – it puts out 1500A pulses – kinda different to the commercial ones! (you need that sort of current to overcome battery capacitance). The beauty of AGM (good ones that is) is that they do not gas – and can operate in any position – and do not require housing in a ‘special battery enclosure (plus you can’t muck with the electrolyte!)

    • Sophie Vorrath 4 years ago

      Hi Hugh,
      Very interesting to read about your experience. Any chance you’d like to submit something like this for our sister publication One Step Off The Grid?I have sent you an email.

    • Phil 4 years ago

      Spot on Hugh . I have triple redundancy with 2 of everything and the genset as the third level. It’s not that much more expensive in real terms and i simply split the solar panels into 2 identical halves each with it’s own mppt solar charger

      I recently had to take an MPPT charger out of service. Fixed the problem and returned it to service. I was on half charge while that happened . But i have double the number of solar panels needed , and it happened to be sunny weather , so it was not an issue with a full charge.Even in cloudy weather it would have just meant a genset start

      So far the entire system downtime over 3 years is less than 10 minutes. Or beyond 99.9999% uptime. This is way beyond the grid reliability.When i was In Brisbane we have 97% uptime one year due the floods.

      I liken off grid electricity to the difference between townwater and rainwater One is unlimited , expensive crap. The other is limited but fantastic.

  7. solarguy 4 years ago

    This is pretty well much the truth, what Ergon is saying. I laugh when people think that 10kwh of storage is all they will need to go off grid!

    • Andrew Roydhouse 4 years ago

      It really depends on how well you’ve done your homework on your real power needs.

      If you have tracked it accurately on a daily basis over a few years then you can get a much better idea of your needs vs generation capabilities.

      In our case over the time we’ve had our solar panels operating we have been net contributors to the grid every rolling 365 day period.

      Analysing how many usable hours of battery storage is needed is a relatively simple matter that can be calculated easily. It then becomes a trade-off as to how much (and what capacity) you use a back-up generator.

      That then becomes a straight-forward trade-off between operating cost and capital cost of back-up generator vs capital cost of additional kWhour of battery capacity vs capital cost of additional kW solar panel capacity.

      Provided you have a well insulated house that requires minimal heating then costs are not so great.

      • solarguy 4 years ago

        Hello Andrew, I agree with what your saying. As I’m a SPS/Hybrid designer I know what is possible, however there are so many people who are used to chewing through 30-40kwh/day, want to buy a property, build a house that’s too expensive to get the grid.
        They don’t realize that to have the same lifestyle, the SPS cost could be $100k.. If their willing to be educated and to compromise, as well as be prepared to get new energy efficient appliances and ditch the house design for a more efficient passive solar design, then marvellous things can be achieved for a lot less.

    • trackdaze 4 years ago

      Why would you want to go off grid It will stop you exporting?

      Sufficient Energy storage to moderate peak demand ought to be encouraged by the network or at least by its regulator.

    • Phil 4 years ago

      I have 10kwh of storage for a 6-10kwh consumption per day system.

      I get away with it because i have 100% more solar panels than a normal system with a 5% panel tilt optimised for cloudy days.

      It takes an east coast low or monsoon type of cloud cover to need a genset start. Even on a really cloudy day you will still get 6kwh as the panel angle grabs nearly all the skylight

      6 genset starts a year is all i need

      • solarguy 4 years ago

        Yep, looks like you have it sussed. But why is your array tilted at 5 degrees, what latitude do you live at? 10 degrees is the self cleaning angle after all.

        • Phil 4 years ago

          Hi Solarguy , Coffs Harbour hinterland is the location

          I set one panel up when i first made the brackets up with an inclinator and confirmed pretty good runoff started at just below 5 degrees

          Never had a problem with dirty panels . I only clean them once a year.

          They are mounted on top of a shipping container with 6 strings 3 panels so i can stay below the magic 120v dc DIY legal level.

  8. wmh 4 years ago

    On cold winter days most energy is used for heating. You need to quantify the energy lost as heat to the outside before you can estimate your heating power and energy storage needs. You could use electric heaters to warm each room and when the temperature has stabilised to your satisfaction, measure the input power or energy over time and the inside-outside temperature difference, to get a figure in watts per degree.

    Energy use can be estimated well enough from nameplate ratings for lighting and all appliances except airconditioners and the fridge where you really need a suitable meter to get a total 24 hour figure, (e.g. MS6119 from Jaycar) together with the peak starting power. Hot water usage can be estimated by timing showers and measuring water temperature.

    At this point you would have enough household data to realise how much energy you might have to provide on a daily basis and work out whether off-grid is a good choice.

  9. MaxG 4 years ago

    Well done Ergon; sums it up nicely.

  10. Geoff 4 years ago

    Congratulations Giles. Your first non Happy Clappy “renewables” article.
    You can learn from the pragmatic Ergon.

  11. Phil 4 years ago

    I think Ergon have done well here and covered all the Key areas.

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