Living off the grid means that I am not ‘plugged into’ the NSW electrical grid, therefore I have to supply my own electricity.
Where I live there are virtually none of the services delivered by our councils that we Australians take for granted, with the exception being the periodic maintenance of the 8 kilometres of dirt road that forms the terminal end of the road into the closest town to here. The nearest power pole is about 500 metres away and in 2012, when I moved here, the cost of having the power extended to my house from that pole would have been about $50.000. So pay $50.000 for the privilege of grid power, and thereafter periodic power bills, or go off-grid solar. I chose the latter.
I’m no expert in electronics, far from it, so what follows is garnered from eleven years of experience of living with an off-grid power supply rather than from technical knowhow.
Some months back I came across a news report posted to my Facebook page from an Australian TV broadcaster that extolled the virtues of renewable energy and the clean green future that it promises to deliver. Reading some of the comments below the article regarding the content of the report I came to the conclusion that none of the people posting those comments had any ideas at all about the every day reality of living with renewable energy. And eleven years ago that was me.
In short: The ‘brain’ of an off-grid solar system is an inverter which converts the direct current (DC) generated by the solar panels into alternating current (AC) that is needed by most electrical appliances to make them work. The inverter, along with a charge controller, then directs AC current thus generated to batteries where it is stored, and then from the batteries to the appliances within the house when in use.
At present I have 12 solar panels which, in ideal conditions of full unobstructed exposure to the sun, collect about 3Kw (3000 watts) of power that is fed via cables to my 3Kw inverter. Therefore at any one time I have 3 Kw of electrical power that I can use. My storage is via two lithium batteries capable of storing 4Kw (4000 watts) each of energy, giving me a total of 8Kw (80000 watts) of stored electrical power.
I haven’t been able to verify the following because I can’t find online what I’m about to type, but some years ago I remember reading that the electrical grid in Australia delivers 23Kw (23000 watts) of power to each household 24/7/365. That 23Kw is a lot more than the 8Kw I have stored in my batteries, and that 23Kw is available all day and night, and is irrespective of any prevailing weather conditions.
So what electrical appliances does my system allow me?
The list comprises:
1 x 53L hot water heater***
1 x 420L LG Inverter Fridge/Freezer
1 x 328L Hisense Fridge
1 x 145L Hisense Chest Freezer
1 x Westinghouse Bar Freezer
1 x Sharp Microwave Oven**
1 x 7.6L Crockpot
1 x Anko 3.2L Air Fryer**
1 x 22L Sunbeam Multi Function Countertop Oven + Air Fryer**
1 x Sunbeam Pie Maker*
1 x Braun MultiQuick 9 Hand Blender*
1 x 1L Russel Hobbs Food Processor*
1 x Optimum Food Processor*
1 x Vevor Water Distiller***
1 x Oscar 9200A Juice Extractor
1 x NutriBullet*
1 x 5 cup Rice Cooker*
1 x Optimum 10 Tray Food Dehydrator***
4 x 1.1Kw water pumps**
1 x 21.5 inch iMac Desktop Computer
1 x 28 inch iMac Desktop Computer
1 x Canon inkjet printer
Items with one * are power intensive, but because they are only used for such short periods of time they could be considered at inconsequential. Items with two * are very power intensive because when in use have to be used for much longer periods of time, with this being especially so for the those items with three * that need to be operated for hours at a time. Using items with two or three * can therefore be a challenge for use in off-grid situations.
Cooking is via two bench top gas burners
So as you can see I can truly live within the 21st Century.
However if I were to turn on or attempt to use all, or just the wrong combination of the above, all at the same time my inverter would suffer its equivalent of a nervous breakdown and would shut off all power in order to save my batteries, which means nothing would work until I turned off some appliances and restarted the system. This does not happen when connected to the grid.
So, from my perspective at least, living off-grid means that one has to be cognisant of how much power one is using at any particular time.
An illustration of what I mean. Today started out as partly cloudy and become totally cloudy by about 2pm. At 7.30, when I water the vegetable garden, my inverter indicated that my batteries were 72% charged. 3/4 of an hour later the 1.1L water pump delivering the water to the garden had discharged to the batteries to 60% capacity. During that time no sun had shone directly onto the solar panels. I left home at about 8.45 and returned at 11.30 to discover that the batteries were 74% charged, and left to its own devices the panels would have probably recharged the batteries close to 100% by the end of the day, even though the sky was now 90% cloud covered. But I could’t allow that to happen because (a) the holding tank at my accommodation was empty, i.e. I had very little water, and (b) I had to heat water if I wanted to have a warm shower tonight. Through use of the petrol generator to augment the diminished power coming from the panels I first used the 1.1Kw water pump assigned to this task to fill the holding tank with water, then turned on the hot water heater for an hour to heat the water to a temperature sufficient for a hot shower. When that was done and the generator switched off about an hour later the batteries were 98% charged. After a ten minute shower followed by a five minute use of the Anko 3.2L Air Fryer the inverter indicated that the batteries were at 95% charge.
There have been a couple of occasions in the past when I’ve been pumping water to the accommodation and having the hot water heater turned on that I’ve tried to use a hose to water part of the vegetable patch to discover no water gushing forth from the hose, i.e. I’d inadvertently tried to run the water heater and two pumps at the same time – it didn’t work, the inverter shut everything down. One day, when I grow up, mummy tells me that I’ll be able to upgrade to a 5Kw inverter and increase the number of storage batteries that I have, and when that happens this type of issue will be resolved.
Apart from being aware of my power consumption and having to resort to the use of the generator when needed living with the off-grid system that I have is easy really, and despite the above-mentioned mindfulness I run the LG and Hisense fridges and the Hisense chest freezer almost 24/7 (see below) and use all of my other appliances, with the exception of the food dehydrator and the water distiller, just about anytime I want to.
Regarding the fridges and freezer: Following a suggestion I saw on a Facebook off-grid group I’ve attached a timer to the fridges and the freezer. So at 11.00pm the timer turns those appliances off and at 6.00am turns them on again. There’s been no ill-effects to the food stored and the batteries are not discharging during the coolest hours of the day.
Regarding the use of the food dehydrator. Every year I dehydrate turmeric, arrowroot and ginger, and this year (March 2023) I’ve started to dehydrate chillies. Due to the location of trees around my place my solar panels receive more direct exposure to sunlight in winter than they do in summer. Also during winter I don’t need to water the vegetable garden anywhere near the extent that I have to in summer. So with more energy into the batteries earlier in the day coupled with less intensive energy being withdrawn I have an abundance of energy available for other purposes, such as dehydrating food. Also, I’ve taught myself a little trick when it comes to dehydrating. Once I’ve thinly sliced what it is I want to dehydrate instead of relying solely on the dehydrator I now use the dashboard of my two cars. I park the cars so the front of them point directly towards where the sun traverses the sky and place the dehydrating food onto plates located on the dashboards of the cars. And very affective dehydrators those dashboards have turned out to be.
This year I’m toying with the idea of using the 180 sq. cm. tray of my ute as a very big dehydrator by placing the food I’m dehydrating onto the floor of the tray and laying perspex sheets on top of the sides of the tray so as to at least partially, or to totally enclose the area underneath the perspex. It should work I think.
For more details on off-grid solar:
https://solarcalculator.com.au/off-grid-solar or
https://www.solarempower.com/blog/what-is-on-grid-and-off-grid-solar-system/