Michael Mobbs (centre) heads off grid.

Here’s a strategy to go off the city grid.

It has worked for some but let’s not see it as tablets brought down from the mountain, immutable commandments. No one’s made a planet sustainable that I know of, and not even one project in a city is sustainable, including my place. (What do I know? I’m just feeling my way toward the light here.)

It’s easier to go off the grid in the country. Often a country house will already be off grid or it will be cheaper by far to go off grid there than to connect. One electricity pole for a farm, for example, can cost $25,000, making an off-grid electricity system the cheaper option.

Let’s see if we city folk can catch up with country folk and go off grid, too.

Better still, let’s switch from being city sheep to being humans who respect ourselves and Earth.

But are they off the grid?

The strategy (1)

Off-the-grid technology is readily available. There are lots of products to choose from and to compare. We can buy it tomorrow at the local plumbing place, tank place, solar shop, appliance shop, timber shop. Local trades can put it in and maintain it for ordinary folk like you and me.

Going off the grid is 90 per cent in the mind, 10 per cent in the products and materials.

What’s not easily found here in Australian cities is something we need inside ourselves – self-belief.

Put fear aside and trust your curiosity. This may sound counter-intuitive – but have fun. Look for those in your project who take pride in and enjoy their work and don’t take themselves too seriously.

No one dies off the grid.

No one goes broke.

Be prepared to build self-belief in the people we depend on when we go off the grid – trades, the design industry, councils, red tape makers like Standards Australia and state governments.

And be prepared for the joy in your heart at the new way you’ll connect with the sun, the rain and Earth.

Here’s a list of the things we need off the grid: energy, water, transport, materials and food – and how to get them.

Get ready

Measurable goals: Put these goals in your building, design and design plans:

  • No stormwater to leave the site
  • No mains water
  • No mains sewer
  • Only recycled timber
  • All energy from the sun or wind
  • All food locally grown
  • No waste
  • Recycled steel, concrete
  • Prefab as much as possible
  • Collaborative design process involving builder, plumber, designer, engineer

Make these goals essential and get all invoices submitted saying the services and materials comply with your design brief and goals.

As we’re not “there yet” with these things allow for exceptions if the goal can’t be met after serious attempts are made by all involved in the project. If you prefer, get there by instalments, so make this easy on yourself.

Budget: $20,000–$50,000

Link payment to delivery: Remember: with these goals you’re buying the result, not the product. For example, with solar panels you’re buying the promised amount of power not the panels. Hold back payment of the balance of the purchase price ’til you and the installer agree the panels are giving the agreed, promised amount of power. Take the same approach to your water, sewage, timber and other systems and materials.

Reduce the energy, water, food and transport you use: By cutting your energy and water use you’ll also cut the cost of the new appliances and systems as they won’t have to make as much energy and water. As food uses 20 to 40 times more energy and water than your house, by buying food from local farmers, farmers markets and growing your own you’ll dramatically cut the water and energy that’s in your food due to the practices of commercial agriculture.

This is only about being efficient. It is not about lowering your lifestyle.

In 1996 our young family made the kitchen and bathroom bigger as we needed more space.

For $48,000 we got a bigger kitchen and bathroom but lowered energy use from 26 kilowatt-hours a day to about 7kWh a day, and water use from about 150 litres a person to about 57 litres a person. Efficient appliances and energy and water systems can do that. Today the same project would cost about $20k because the same solar system can be bought now for about $3k instead of the $26k it cost back then.

Since 1996 the four-person household has had energy and water bills less than $300 a year.

Anyone can do this. Here are some things that work in our house and can work for you, too, as you get ready to go off grid – they’re intended to lower your energy and water use:

  • Turn the fridge down – Your fridge can use most electricity as it’s on 24/7. By turning it down a degree or more you can still keep your food in good condition as well as save up $100 or more a year
  • When changing a light bulb buy an LED – LED’s use about a quarter or less of the electricity of light bulbs and last at least five times longer
  • Ventilate your fridge – Your fridge can use half of your energy and all of the energy from your solar panels if you have them; by ventilating your fridge with cold air from below your building you cool it so the fridge engine does not come on as often and does not have to work so hard to cool it – this means your fridge uses less electricity
  • Grow plants on your western wall – By shading your western wall from the sun you prevent the sun heating up the wall in summer and heating up the inside of your house – this is cheaper than insulating the wall and more efficient


Let’s deal with electricity first.

Space: About 30-40 square metres for solar panels (from 260 watt to 327 watt each) – about the size of a 600-litre fridge for an integrated lithium ion battery and inverter

Weight: About 500 kg for the inverter and batteries (about 1.5 tonnes if lead acid)

Cost: If purchased as a one-off for your place about $25–35k, but if purchased as a bulk purchase with over 15 other buyers about $20k

Capacity: If you can get the daily average electricity use under 5kWh a day then a 4.5kW solar system with at least 10kWh of useable battery storage should mean you have enough capacity. The key here is to get the most efficient appliances (choose a fridge that uses less than 400 watts a day) and use natural light wherever you can.

Warning: Tesla, the battery rock star of the moment, only sells, services and warrants its battery. It does not provide or sell the inverter needed to put the sun’s energy into and out of the battery(s), so you have to deal with two product suppliers and possibly two installers if you choose to wait until late next year when Tesla batteries are expected in Australia.

Advice to me is that most inverters in place in Australia will not work with the Tesla and many other batteries in the market here now. It’s hard to assess Tesla founder Elon Musk’s assertions that no new inverter is required for his battery as his company publishes no technical details that I have access to. Most of the inverters being used now will have to be replaced when new batteries are installed.

I had to change my existing solar inverter to put in batteries here and that applies to all the other battery products on the market at the moment. Generally, over the last decades, I’ve learnt to make decisions based on facts not assertions and I won’t be drawing any conclusions upon Mr Musk’s assertions until I get the facts in a technical data sheet. Would you?

Note to solar industry: how about promoting a recycling industry? My old inverter and solar panels are still in good working order but are unused. I gave them away but as the solar subsidy doesn’t apply to either it’s cheaper to buy a new inverter and panels because the subsidy reduces the price so much that the labour to put in the old panels and inverter costs more than the new system. How sustainable is that?

On 31 March 2015 I disconnected my house in Chippendale, Sydney, from the poles and wires. Since then the electricity has come from the sun through an integrated battery and inverter system.

It’s been a learning roller coaster with system outages requiring visits to friends and the local pool for shower and clothes washing, and lots of to and froing with suppliers, products, contacts and ongoing research as I seek to educate myself.

I’ve leant on Samuel Beckett’s advice which I put as, “Fail. Try again, fail better.”

The system failed because the software didn’t work.

It’s clear to me now the system was not ready for market.

The manufacturer upgraded it and the installer visited three times with a USB to install the upgrades into the batteries. Unfortunately, the installer failed to re-connect the main data logging system (a Wattwatcher system) so the capacity to obtain a full record of energy generation and use data has been missed. Note to self: data is essential when designing, monitoring and amending off-grid systems. The incomplete data is pieced together in the graphs and summary (3):

Comparing the house’s daily solar production, energy consumption and battery life

Law: Some key legal issues for going off the grid for electricity and for setting up a local power station include these – for the full legal advice see the Street Coolers website.

Here’s an example of a legal issue answered on the site:

Question 1: Is it lawful to disconnect from the local distributor’s network?

Answer: Connection of premises to a distribution network is at the election of the occupant of the premises, and requires an application and agreement (usually in standard form) with the distribution network service provider.

If the premises require electric power for essential purposes such as lighting, mechanical ventilation and/or smoke detectors, then it may be necessary to demonstrate that electric power is available to the premises, before a certificate of occupancy can be issued for the premises.

While connection of the premises to the local distributor’s network is a common method of demonstrating the availability of electric power, for the purposes of obtaining the certificate of occupancy, demonstration of the adequacy of alternative electric power sources to provide those essential services is an alternative method of satisfying that requirement.

We city folk face different challenges with electricity and gas to those in the country which include:

  • lack of space: the five or so square metre array of lead acid batteries needed for a four-person household may not be available in many city house sites
  • structural limits: lead acid batteries are typically on the ground due to their weight and often well away from a house in case they catch on fire
  • differing financial and personal incentives: each new electricity pole to a farm costs between $15k to 30k and staying off the grid may often be cheaper than going on the grid. In the city where we’re all connected, and most people don’t care or have this as their priority, for change to happen there it has to be cheaper to go off grid and disconnect than to stay connected; and farm folk often are “connected” to Earth and “get” this clean energy issue.

Now, to gas.

Starting with my place, it’s still on mains gas for cooktop cooking, boosting the solar hot water and the oven.

Once I learn how the solar and battery system performs through this winter I’m moving on to disconnect from gas, which will be later this year during summer.

The cooktop is used at least three times a day and will be replaced by an induction cooktop. Some newer ones are cheaper, use less standby power and, I’m told, are similar to the experience and ease of gas cooktop cooking. Lots of research to be done here and I’ll report what happens.

New kitchen in Sydney’s Sustainable House – just like any other ordinary Australian house on the grid


To be self-sufficient and disconnect from mains water and sewer the house needs a total of 15,000 litres storage minimum (for drinking, cooking, bathing) and 3000 litres for a recycled water system for clothes washing and toilet flushing

The rainwater need not be in the one tank but may be in several that are connected


You can recycle your sewage in cities to irrigate your land. You can also use it to flush toilets and the garden.

In NSW, so long as you use a system accredited by NSW, a local council has no legal power to refuse consent to the use of an onsite system in any town, city or place. After some 20 years dealing with local councils in NSW and their health folk I can say with confidence that the law on this point is completely unknown to them and to the onsite system providers. All the accredited systems are listed on NSW Health’s site.

This part of the off-the-grid world is locked in a dark and primitive place somewhere near the set of Mad Max where ignorance is bliss. There are few players, and few good products – perhaps six or so at most. There are over 60 million onsite systems in the US where the US EPA, in partnership with industry, strongly promotes education, best practice and research – three times Australia’s population; go figure.

It’s much easier, and the guidelines are less demanding, to get commercial sewage systems approved. There’s no scientific basis for this discrimination; but it’s there to be used. You might, for example, join with neighbours, or put a few lots together, to install a commercial system?

While it’s difficult, tedious and time-consuming, fossicking may turn up some rare folk in the industry and government who you can turn to if you wish.

For a full legal advice about on site sewage visit the Street Coolers website where you can download it as a pdf.

If you want to park this aspect you might, at least, future plumb your place with separate, unused pipes to the toilet(s) and clothes washing machine and garden tap(s) so you or a purchaser can connect to them later.


This can use more energy and cause more pollution than the systems supporting a house, so it’s big. It’s also the toughest for most Australians.

  • If you’re buying buy near a train station
  • If you’re not near a train station use the bus
  • If there’s no bus or train or car share and a bike is not an option but you need transport, buy a second hand efficient car
  • If its available use car share instead of owning a car
  • Work at home or in walking distance if you can
  • Walk

Yes, the options on this list aren’t available to most Australians. Most of us are locked into using cars because of the way politicians and designers have designed our cities. Some few cities overseas have made dramatic and successful changes to this but this is not the place to cite those examples; some are referred to in other articles in The Fifth Estate.


Food is key to going off the grid because it uses most energy and water and causes most air and water pollution – more, for many of us, than transport.

Buying food from local farmers and growing your own is the best you can do in the city. Look for the farmers markets closest to you.

Let’s compare the water in food with the water in our houses.

Four people in my house use less than 230 litres of rainwater a day for cooking and washing.

Yet a modest breakfast of commercially grown food uses over 1100 litres; that’s a brekky with an egg, small punnet of yoghurt, a slice of bread, a tomato and some bacon. Three meals a day for one person will need over 3000 litres of water.


This can be the toughest in the to do list as the design and building folk mostly lack experience or the will to use off-the-grid materials. There are a few who willingly learn or have the experience; an audited contact list would be handy. In the meantime here is the list of materials to use:

  • Only recycled timber, only recycled concrete, cement
  • No tiles – in the bathroom and kitchen use steel and timber – for an example of a sustainable, beautiful, award-wining bathroom we have to go to one of the countries with earthquakes where timber is used, such as Japan or in this particular example, New Zealand
  • To cut waste and building time get as much made off site as possible for example, stairs, buy modular second hand steel kitchen benches from commercial kitchen outlets or on the internet
City dreaming in Maroubra, Sydney, where bigger is better and aggressive blandness is all.


The sustainable development sector in Australia is, I think, a huge failure. It’s a minor player in our culture.

We have to work harder than we need to get an off the grid project. It’s far easier and cheaper to build on the grid stuff. The behaviour, attitudes of local, state and federal governments may vary a little around the edges but the reason our cities are vastly on the grid is our governments and those who they truly answer to are vast owners, profiteers and controllers of the rules and financial systems underlying the grids.

Despite this, having met over 20,000 people who’ve visited my place over the last 20 years I know there is widespread passion and enthusiasm among we Australians to go off the grid.

There is rampant failure in the sustainable sector to build what’s promised, to make claims which are wrong, poor quality controls, second rate business models, and poor strategists abound. Without the subsidies, for example, the solar industry would not have grown so fast, as it has no initiative and is under-capitalised. We need multi-billion-dollar companies with skin in the solar game – urgently.

Perhaps the greatest failure lies in the red tape sector. Why, for example, aren’t off-the-grid projects fast tracked instead of taking longer and costing more for approvals than the muck that is approved each day?

Since 1996 almost no water – no more than about 5000 litres – has left my site. But now, 19 years on, Sydney Water is still insisting I pay a stormwater levy to it and Sydney Council (remember, “Green, global, connected”?) still also charges me a stormwater levy.

Even in the tumultuous (another “one hundred year event”) Sydney storm this year no water left my house. So there’s no financial incentive or reward for a house that goes off the stormwater grid. Laughably, Sydney Water drops me a note now and then threatening to disconnect me for not paying the stormwater levy. Those folk should get out more, you know, read a book like, Sustainable House. A card saying “thanks” would be nice.

Just my thoughts.

May the sun and the rain be with you and upon your roof.


This is written for Belinda Bean and those at Macquarie University Sustainability Cottage in response to Belinda’s email to me: “Mobbsey!!! I’m trying to pull together an off-grid strategy for our little sustainability cottage here at MQ – something we want to achieve in three years time. Have you seen anything in the way of an off-grid strategy or succinct energy management strategy I could model off. Just to help get my head around things. Belinda Bean”

(1) Costs and assumptions are for a four person household.

(2) An example of the issues faced by going off grid in the country is here:

(3) In providing the following details on data analysis I’m delighted to say “thank you” to my colleague, Marianna Verlage, and to all the fabulous young people working in the off the grid space. They’re in small, medium and large companies; in local, state and federal governments; folk I talk to in the street, on tours of my house and can be as young at five or six and in their teens, twenties and thirties. I love talking to you all and being inspired by your simple, infectious enthusiasm. Here’s some early analysis by Mariana of the data we’re getting from the off the grid electricity system – enjoy:

“We are trying to build graphs that show the continuous usage, production, and battery life at Michael’s house and because we do not have access to raw data files, the best I could do was to get the daily values that I sent you earlier today. It took about three hours to compile that information going back to March.

“Because we now know that the total production values are not accurate (thank you for your advice on that), I am having to pull daily files from Tigo’s monitoring system to at least get production values for the new panels. This will probably take me another two to three hours because this process is very manual as well (I am able to download data files but they are individual daily files and I then have to aggregate all the data).

“Just my time to collect the data (I haven’t even begun to analyse it yet) is costing Michael about $240.

“Again, I wanted to share this information and be completely transparent about the data collection process this time around. A lot of Michael’s work depends on sharing accurate information with people, so having easy access to reliable data is imperative moving forward. Hopefully we can come up with a solution where this process of collecting and analysing energy data for his house can be streamlined.”

Comparing the house’s daily solar production, energy consumption and battery life

Of the 27 days recorded for July, 11 of them had consumption that exceed solar production. On those days, solar production was on average 35 per cent less than the house’s consumption.

Six days in July were recorded where the battery life reached below 10 per cent. This is when we start seeing inconsistencies in reporting and system outages. Increasing the storage capacity by 2kWh will help with this issue.

Although there are only six Tigo panels installed at the Sustainable house, the solar energy produced by these new panels for the month was 61 per cent of the total solar production.

Examples of Alpha ESS reporting: comparing good reporting days with days where we had outages

When there is a system outage, the Alpha ESS software stops recording production, usage and battery information, which leads to daily values that are unreliable.

However, this is the most accurate reporting system we have for the house and is the one we used for the graph above.

For transparency, we have included an example without a system outage and one with an outage.

Example of a day with sufficient battery life and accurate data reporting (23 May).
Example of a day with insufficient battery life causing a system outage and incorrect reporting (11 June). System outage occurred at 22:30.
Tigo panels monthly solar production.

Since their installation in March, Michael’s six Tigo panels have saved 151.17 kg of CO2.

The Tigo panels work to maximum efficiency despite some being shaded.

The upcoming panel installation at the Sustainable House will work in the same way and will increase the current array’s efficiency by roughly 20 per cent.

Full data is available here.

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  1. The city has one advantage over the country RAPS installation.
    Renewable production varies. Such as PV fluctuating 30% to 100% winter to summer in line with length of day time, solar intensity, cloud cover, etc.
    Neighbours can share resources in the city (Radburn style), where oversupply in one part is re-directed to unmet demand nearby. Including people away on holidays on one side, people with visitors on the other, with the emphasis on building community (kerbside garden style) where a normal part of the conversation is relative use of resources for both individual family and overall community ‘health’ and benefit. (see 105 Sturt St., Adelaide by Dr. Paul F.Downton)

  2. Hi Michael,
    I visited your house when you installed the waste water tank in the backyard.
    The massive problem your ideas have is that they are individualistic. Imagine if your ideas caught on and lots of people installed their own water systems.
    Soon politicians would be under pressure to cut back spending on mains water. But mains water and sewer delivered the great breakthrough advance in public health. You effectively are promoting an anti-social, every man for himself solution. That would take us back 250 years and create a new dark age – not for you and your kids of course, but for all those who don’t have your financial resources to develop and maintain a safe off grid home.
    And finally yes – you do owe Sydney Water money for the stormwater levy. its called living in a community.

    1. Its rather ironic to suggest that Michael is not being community minded in his actions. While many of the centralised services we use are valuable they also in many cases have very serious negative consequences upon the broad community and the house demonstrably reduces those consequences.

      Coal fired power is one of these. The mining processing and burning of coal is the largest source of toxicity of any human activity.

      • 7.7 billion tonnes mined and burnt annually.
      • It is the dirtiest of fuels.
      • Coal death toll: China suffers 670,000 smog-related deaths each year.
      • The single largest cause of global warming.
      • Coal-fired power plants are the largest source of mercury emissions on earth. Reference https://www.nrdc.org/international/china-us-mercury-limits.asp

      An average grid connected home in Australia produces around 6 tonnes of greenhouse gas per annum from fossil fuels powered electricity. Despite our vast renewable resources, Australia’s power grid is THE dirtiest and most polluting power grid in the western world per MWh.

      Avoiding runaway climate change requires a rapid reduction in emissions.
      Minimising our personal reliance on the coal powered grid while also advocating for a radically greener power grid is a vital and urgent priority.

      Water is a truly limiting resource in Australia and we are stretching the supplies we have and unconstrained growth in water consumptions drives new dams which have serious negative consequences. The construction of desalination plants is clear evidence we are stretching our centralised water supply assets.

      What Michael has done has clear community benefits. These include
      Reduced demand from coal fired power stations, lower greenhouse pollution and mercury emissions.
      Decreased demand for new dams and flooding valleys.
      Decreased demand for natural resources like timber though the use of recycled timber, so our forests are less impacted.
      Decreased toxic runoff into streamwater through the use of non-toxic materials.
      Increased awareness in the community regarding the real extent of our environmental impact on multiple fronts, which when we rely solely on centralised services tends to lull people into a blissful ignorance of their very extensive impacts.
      Increased awareness among others of the opportunities for adopting elements of the system even without going off grid. For example, we use 50% more energy in our homes that we need to simply because best of breed efficient appliances are not being used.

      We need to shift to a a judicious combination of BOTH less impactful centralised and decentralised services like energy and water. We need to reduce waste and the consumption of natural resources so that can live sustainably where currently humans are by no means living sustainably.

      This is a big and complex challenge which requires the efforts of many. Part of the way to get there involves pioneers who are working at the leading edge trying radical new approaches.
      It requires first developing sustainable approaches and then working out how to systematise them and scale them up to city and regional levels or into marketable products and services. It’s necessary and vital.

      The project and the ideas for others has clear community benefits and to suggest otherwise is incorrect.

  3. Thankyou Michael for another initiative to push the environmental envelope. You have been as inspiration to me for many years.
    I am currently looking at systems to enable our clients to go off grid in the homes we build (that like yours generally use very little power) however I am still debating with myself as to whether going off grid is actually a model we (society) should be following. The grid itself is actually a useful piece of infrastructure, which does negate the need for batteries. And regardless of the fact that we get a useless feed in tariff at the moment for exporting, is it better from a social point of view to stay on the grid and aim for producing more power than we use (on average) and sending that back to the grid as green energy for someone else to use? Your thoughts?

    1. Hi, Jeremy, thanks for your feedback and this question, “And regardless of the fact that we get a useless feed in tariff at the moment for exporting, is it better from a social point of view to stay on the grid and aim for producing more power than we use (on average) and sending that back to the grid as green energy for someone else to use? Your thoughts?”.

      I asked myself this question, too, this year and the answer I chose was to go off grid as I wanted to stop using dirty electricity – I was polluting our air by using it.

      Since 1996 I’d been prepared to pollute Earth’s air as the alternative (dirty, inefficient batteries) wasn’t attractive.

      Now new tech batteries are clean and efficient the balance weighs, for me, at least, towards batteries and no dirty grid power. I’ve yet to calculate the embodied energy in the new lithium batteries, though. Time will tell the answer.

      But, I feel to my core, and am persuaded by the science, that we must stop using dirty power right now. As for the benefits of the grid; yes, uni, hospitals, etc need it for the moment. But they can make their own solutions, too, if they wish, now.

      Just my thoughts, Michael