Until recently, Australia’s incumbent utilities – both network and gentailers – would have comforted themselves with the thought that going off-grid in a big city would be too expensive to contemplate.
A report from the Grattan Institute in 2015 suggested that taking an average home off grid in the city would cost around $72,000. It simply didn’t believe that it was going to happen.
The continuing fall in the cost of rooftop solar, and the plunging cost of battery storage, has turned that assumption on its head.
SA Power Networks, which delivers electricity to 850,000 customers in South Australia says the cost of of solar and storage will fall to around 15c/kWh before long, less than half the cost of grid power. Little wonder the networks lobby is calling for radical change of policies and rules to stem the potential loss of one-third of their customers.
Roger Franklin, a resident of the Brisbane suburb of Wynnum is a typical case in point. He got so fed up with the soaring cost of gas and electricity – and their surging “network charges” – that he decided to cut links to both of them.
He dumped his contract with his gas supplier, which was costing him $2 a day just for a connection, and decided to instead install LPG for his hot water and cooking. He then cut off the electricity supply, after installing a 6.5kWh LG Chem battery storage system to go with his 4.2kW solar array.
Already, his bill as gone from a combined $600 a quarter for electricity and gas to just $20/quarter –the average cost of replacing his LPG bottles.
The battery storage and the controls that go with it were installed by Brisbane-based software company Redback Technologies.
CEO Phil Livingston isn’t actually a supporter of individual homes and businesses going “off-grid”, but admits it is inevitable in some cases.
He uses this example as an illustration of what could happen, and the implications of new technologies and their plunging costs.
“This is an extreme example, but it proves a point,” he says.
“Self consumption of solar- generated electricity is the number 1 motivation for many consumers …. And what this shows is that even with small battery, going off-grid is a possible scenario.”
Today, Livingston adds, Redback Smart Hybrid systems with similar PV array sizes and battery storage capacities as Franklin’s can be bought and installed for under $10,000.
Franklin’s system in Queensland, a state with some of the lowest electricity prices nationally is saving $2,400 a year as a result. “You do the math,” he says.
Looking as part of an overall energy system, Livingstone says Redback “doesn’t see much value “in such a scenario.
“But (we have to acknowledge that) this is a very real scenario,” Livingston says. “We are seeing a significant proportion of customers moving down this track … a double digit percentage.”
This fits in with forecasts from the likes of the CSIRO and network owners lobby, who suggest that more than two thirds of homes will connect with solar, and if they don’t get a good deal from utilities, around one third will quit the grid altogether.
To avoid this scenario, they suggest, Australia needs to start changing its energy market rules to allow the adoption of new technologies to accelerate, and adapt to this reshaping of the energy market.
Franklin’s household uses around 8kWh of electricity a day. Most of his appliances – such as his reverse cycle air conditioning – are scheduled to run during the day, and he has a smallish quote of around 3kWh for the evening.
The graph above shows a typical recent day. In cloudy weather, the battery storage system is fully charged by around about noon (that’s the red line at the top).
The solar array meets Franklin’s day-time needs and fills up the battery. After that, it becomes a “load follower” – providing enough power during the afternoon to power the house, while excess power is spilled.
When the sun goes down, the battery storage is discharged, powering the house.
On average, Franklin wakes up in the morning with around 45 per cent of his battery capacity still there, sometimes it falls to 30 per cent.
The lowest he can go – the depth of discharge – is 10 per cent, so maybe winter will provide some challenges; but while the days are shorter and the angle of the sun is lower, there are usually more clear days. Time will tell.
“We think he’ll make it. It might get down to 15-20 per cent .” There is no back-up generator, so if it does go below 10 per cent, Franklin will do without lights – something that he is prepared to do.
Giles Parkinson is founder and editor of One Step Off The Grid, and also edits and founded Renew Economy and The Driven. He has been a journalist for 35 years and is a former business and deputy editor of the Australian Financial Review.
This post was published on March 29, 2017 8:00 am
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View Comments
Giles,
Franklin is using LPG for hot water and cooking, we also use LPG but only for cooking as an ET SHW system takes care of the hot water @ close to zero cost P.A. and we spend about $20-30 / quarter on LPG.
Franklin is using LPG for hot water and cooking, we also use LPG but only for cooking as an ET SHW system takes care of the hot water @ close to zero cost P.A. and we spend about $20-30 / quarter on LPG.
My only conclusion is the he:- 1. lives alone and takes extremely short showers and or misses a shower a few days a week. 2. doesn't all ways use gas for cooking (perhaps microwave)
As the Redback inverter can't use a genset for back up, he is going to be a very unhappy chappy, when more than 1 days bad weather happens, as his PV is too small and so is his storage.
So get used to using only 2.3kwh on those days Franklin and hope they don't last too long.
Breakthroughs in battery cost and performance are coming, as well as solar. They'll be able to afford lots more batteries, and more solar.
Yes Mark, But later down the track. This guy wouldn't have got all this, i.e. 4.2kw PV, 6.5kw battery, Redback hybrid inverter plus installation all for under $10k.
More like $16k. And as I said bad weather is going to leave him an unhappy camper, anytime of the year. Sure in good weather he is going to be ok. And I don't know if I believe the claimed $20 for gas every quarter either.
I know this because I'm a designer and installer.
Solarguy
You are correct in your numbers - around $15k installed and the gas numbers - $100 for the year and yes, I do not believe it either! I was working on around $160 per year so better than expected. Putting most of it down to the Bosch Instant Water Heater - seems extremely efficient. Cooking - just a regular gas stove.
Never been unhappy with the solution and have come close to camping during cyclone Debbie, however in the end I had power where as my neighbours didn't - for a few hours at least!
One of the reasons I went with the LG Battery solution was the ability to add a second battery should the need arise. I also knew that the price of batteries would come down and their energy density would improve - and honestly I expected to be adding a second battery in the April/May period when the days got shorter - however there was no need. You certainly watch the weather more - in particular tomorrows weather, but apart from that - after about 6 months I stopped checking the system every few hours to once a day.
What has been interesting is the performance improvements that Redback have made to the inverter. These improvements have been all software based and have improved the charging times and the user interface.
I think we are all in agreement that this is not a solution for everyone in all locations. Moving 200km up or down the coast would change the solution - however for me it works out just ok!
Hope the system designing and installing business is going well
Regards
Roger
Giles - interesting post and below are the answer your questions
1. Live alone
2. Shower at least daily
3. Living proof I cook each day
4. Backup Generator - stay grid connected if you feel you need that. Certainly cheaper, quieter and as you say - it would work with the Redback inverter!
5. I live in SE Queensland so have very few multi-poor weather days. Cyclones are devastating to solar power production - but honestly, I had more power than my neighbours who lost power twice during the last cyclone. If you life in Melbourne - best to allow for 5-8 days of zero solar generation. That or stay on the grid!
6. Your 2-3kwh on poor weather days is about right - but I only need 60-90 minutes of clear skies to get the battery topped up again.
7, Microwaves are good for making pop corn and thawing out the dog food in a hurry when I forget to take it out of the freezer - don't use it much more than that. Prefer to cook on gas!
8. Use a drier - great for towels - but during the day.
9. Coffee machine is well used - it is the 1.8kw line on the chart above - thought about cutting down on drinking so much coffee - but thought again!!
10. Jugs, Toasters all use 2kw+ of power, but not for long and yes I have and use these too!
11. Dishwashers may use less water than washing dishes in a sink - but boy do they use power!
12. My fridge uses the majority of my overnight power
13. LED lights are just amazing.
14. Builders with compressors overload the system when they plug in!
15. I have a max current draw of 5kw (or there about) so two major appliances on at one time is fine. This could be a big issue for some house holds who want to run everything at the same time.
16, Kid and older people get off the grid. Kids run around turning off everything and older people just smile and nod in a knowing way. The people in the middle all say - "so what happens if I turn everything on in the house at once - how long will the battery last then ha!" My response is around 1 second - before the inverter cuts out due to overloading.
In summary - I use around 8kw of power per day, I eat many times during the day and shower at least daily (but not for hours at a time) and yes live alone - but working on the last one! (thanks for asking!)
Anyway - made it from the longest to the shortest day without loosing power and am looking forward to the days getting longer!!
Regards
Roger
Not sure where he got $10000 figure from - I reckon $12500 for battery, inverter, and panels inc installation and STC Rebate.
And I would say panel size is too small for Winter days, and cloudy days. I would usually go with at least 6kW.
Yep Garry, Starting to get on the money, all up though it would be even more than that, like about $16k.
Correct - was around $15k installed - will save $5k over 10 years by moving from Town Supply Gas to LPG. I think they included this in the $10k number - slightly more to the story!!
Roger
Winter days are interesting but Cyclones are devastating to solar power production!
Would have put more panels up but have no more roof space!
Regards
Roger
His battery system could do with an upgrade to 10 KVA as evidenced by it is fully charged by 11:00. Then all the negative comments (and he does not need more solar panels as evidenced above) would allow him to go through a cloudy period, when he doesn't need to run the air conditioning anyway. I say "Good Job" and he does not need to go without lights, just use LEDs at 3-5W
The only reason his battery is full by 11am is because it is only 6.5kwh and has not been completely discharged. If his PV was increased if nothing else it would go along way to helping over come the battery short fall. Having said that he should have spent the extra bucks and gone for the LG 9.8kwh useable, as well.
Not negative just facts!
Solarguy - 100% correct, long term I may add a second LG 9.8kwh battery which is one of the reasons I went with LG. With nearly 9 months of daily cycles, the LG is still charging up to full capacity 97% of the time - with around 3% getting back to the 75%+ range due to cloud/rain /cyclones etc
The best analogy is a car's fuel tank - generally sized at 50-75 litres depending on the size of the car to give a 500-750km every day range - which covers 95%+ of trips. Very few have 150+ litre tanks to cover the twice a year road trip. 6.5kw is more than enough for 95+% of the time.
Regards
Roger
Good as far as it goes but for more avoidance of fossil fuel, I think off-grid houses might find they need to go back on the grid. The hot water could be solar or a heat pump running though the day direct off the solar PV. There would be less for the battery but it would get rid of the LPG fossil fuel use. Then what about the car? When that is an EV, electricity requirements might go up quite a bit, enough to use perhaps a third or half of the PV output. Perhaps then backup would be needed often enough for it to be nuisance to be off grid.
Yep, all practical considerations Peter. SHW over heat pump any day. He will still need LPG for cooking and it is the cheapest way for the most part. A cheap genset will get him out of trouble, but it can't work with the Redback inverter and because of that, can't charge the battery, just run loads.
Should have said 'and an induction cooktop to get rid of gas altogether'. I have friends who swear they are better than gas for cooking on. Also friends who swear a heat pump for hot water is preferable to direct solar hot water if the roof space is used to allow more PV. Once the water is hot, the space is making more electricity for the battery. A neighbour with a new heat pump hot water system and large PV is using very few kWh's per week on the high COP heat pump and she assures me she showers every day.
Induction cook tops ok when there is plenty of solar, when there isn't no joy, use the gas!.
On the HP, NO! Takes away from A/C usability.
One of my customers thought that but wouldn't listen, he already had a HP, but was soon disappointed. He now has a ET SHW system that I sold him after doing his PV, now he said to me ,I wish, I had listened in the first place. He is grid connected. All happy now.
HP HWS and off grid PV are very bad partners.
Think hard about why I have stated that!
I had the option to have solar panel powered hot water on my build but decided to stick with a standard hot water system. One of the reasons is that the various inverters could be single point failures.
So even if the PV system turned to ash, I would still have "solar hot water".
Note that I have a hybrid system atm.
Sure. Redundancy/backup is a good thing. That is one of the reasons that I am a bit sceptical about enthusiasm for being off-grid in the suburbs, even if you have enough roof space for PV to replace big fossil fuel consumers such as hot water, space heating/cooling and petrol cars.
Peter - I used all of my roof space for Electric Solar Panels and agree that LPG is still a fossil fuel but gas is great to cook on and space wise, LPG Instant hot water heaters are small. As for Induction cook tops - have a portable one that is amazing - but did not feel that I had the battery storage to use and rely on electricity for cooking - which I largely do in the evening.
Regards
Roger
Roger hasn't supplied a depth of discharge/battery lifetime graph, so I wonder just how long his batteries are going to last if he takes his depth of discharge down below 50%?
Radbug - LG Chem battery seem to think that it has a 6000 cycle life - which give is a 15plus year life with 80% capacity. Can only say that after around 220 cycles, there is no difference in performance. Ask me in 15 years.
Regards
Roger
I take my hat off to Roger and family in being brave to go off grid. Perhaps current finances are an issue but if I was Roger I would seriously think about adding extra solar panels and battery to give insurance for a run of days that are less than blue sky. Could we get a progress report from Roger in a few months to tell us how things are working out for the family.
Yes you can do it for less than 10K a lot less, We did it for 7K we have been using my system for over a year it works great. We have 6Kw of second hand solar panels on the roof, two new PIP4048 4Kw inverters that work in parallel so 8Kw inverter and a second hand LiFePO4 20Kwh usable battery we use about 25 Kwh per day thru summer with the AC on 24/7.
we also have Grid and when its cloudy we just switch back to grid.
I am also building an electric car a VW Karmann Ghia with an AC50 motor.
as Elon says if you aren't part of the solution you are part of the problem.
So what are you waiting for?
Tom - your system sounds fantastic - would love your 20kw storage, more for piece of mind than actual requirement however . Using the Air Con during the summer - I used around 25kw per day too - but turned it off at night as I live close to the sea and normally have a coolish breeze. My normal power usage is between 6.5-9kw per day. Love to hear more about your car too
Regards
Roger
Well guys for the record I made it from the longest day to the shortest day without loosing power - but it was close during Cyclone Debbie! To answer some of the comments, I have occupied all of my north facing roof with panels so it is what it is!
Does it work - absolutely! There is been a huge learning curb as we learnt how to manage our energy consumption, in particular maximising our daily use of power. The Redback inverter has been excellent with no major issues. The IG Chem battery has been perfect too
What would I change - more battery storage, which to be honest I expected to add at some stage - was just running out of vital organs to sell to buy more! Some surprises - everyone focuses on Clothes Dryers using a lot of power - well Dishwashers do and the one that nearly nailed us - an Cloths Iron! Yea I know - who irons their cloths... Me!
Long term I think we will most likely add more storage to give us more breathing space but that is about it.
Has there been some funny moments - way too many to mention. The best would be the neighbours running in during the last power cut to see why we still had power.....! Made them a cup of coffee and sent them home with a few torches! Others include door to door solar sales people (honestly guys - look up before knocking on the door) and new power companies trying to save you money by moving your plan to them. He wanted to see our power bills and thought we were being funny when we produced blank pieces of paper! Builders - well the first thing they do is plug there huge compressor into the power..... which overloads the inverter so everything goes very quiet for 30 seconds while it restarts and we unplug their compressor.
But to be honest - unless we tell people that we are 100% solar powered, you really would not know - and that was the aim!
Would I do it again - Yes, in a heart beat. Will it work for everyone - NO, but it will work for a growing group of people who want to make it work and live in a location where there is ample sunlight. If you live in Hobart and use 40kw per day - I really hope you have acres of roof space and alot of money to buy storage!
As the price of storage comes down - more people could take advantage of it - but will they - lets see. There is no doubt that the existing energy generators and distributors have deep pockets, are politically well connected and are likely to do everything it can to stop or slow down the role-out of house hold storage, as household storage is the key to disrupting the energy market as we have known it.
If you are thinking of going off the grid - plan well and do it!
Regards
Roger