This has been a long process starting some years ago and culminating with going fully off grid in June 2015. My wife and I have a lodge – www.dreamlodge.co.za which has 3 cottages we built to be off grid, all have solar water heaters, 2 have candles and paraffin lamps for lighting and the other has solar PV (12V running a few lights), gas fridge (an antique), a gas stove, and a wood stove for heating.
Since the beginning of 2015 we started taking our house off grid as well so as to finally say goodbye to utility power.
We already had a 300l solar geyser which we had used for years, and a gas stove and oven for summer and a wood burning stove for winter:
The first step was to get a generator for when everything goes pear shaped (sun doesn’t shine etc). So I was hunting around for a reasonable priced genny. I then came across this advertised secondhand, and couldn’t resist it!
I didn’t know anything about these type of engines when I bought it, but figured it out over time. They are very simple with very few moving parts and will run on a variety of fuels including diesel, veg oil, old engine oil and various blends of all of these.
Apart from reconditioning the head, the engine was working. It also took some time to figure out the the packet of brushes I got amongst all of the other spares, were actually supposed to be inside the generator, so once they were in I had lights!
Reconditioned head and new OEM Lister head gasket :
Eventually the copper head gasket turned out to be a problem as it leaks a bit of coolant from between the copper sheets, but I have a more modern gasket on order to replace it.
Now I had to build a room for the genny to live in, and for the PV panels to live on top. The old bathroom/kitchen on the original house had the main distribution board where the Eskom feed can in so that was the obvious place:
I removed the rusted old roof, and broke down some walls for a new door. Then I built a concrete block to mount the generator on:
And finally install the genny. Note the electric light!
So now the genny was working, next was to get the solar up and running. I built a frame for the PV panels from angle iron on the roof of the generator room. The best fit for the roof was 6x300W panels:
And finally, hook the genny, panels and some batteries together:
Currently I have a 6KVA JSM Power inverter/charger to charge the batteries from the generator and supply the 220VAC for the house, 1800W of panels into a Microcare 60A MPPT charge controller. At that stage there were 4x 150Ah Trojan T1275 batteries in series to give 48V, which I have since increased to 8 batteries.
The generator is now installed at the other end of the room and I am busy with a waste heat water heating system which I will describe when it is complete. The cooling for the engine is by thermosiphon through a 150 litre water tank. After you have run the generator for about one hour, you end up with 150l of water at 50 degrees celcius. This water I would like to circulate through radiators in the house for winter heating.
In total we have the following free energy/energy saving gizmos:
Wind pump – 6ft Climax
Solar pump – Watermax OB with 200W of panels
700W 220V pump connected to house inverter (failsafe for when the other 2 don’t work)
Main house : 300l Sun tank high pressure flat panel indirect geyser
3 Cottages : 3x 150l low pressure tube geysers (various suppliers)
Big kettle on the wood or gas stove….
Extra jersey :
Wood burning fireplace x2
Wood burning oven x1
Smeg 5 plate gas stove & oven
Jewel wood burning cast iron stove
House – 220V LEDs throughout
Cottages: Candles and paraffin lamps x 2
12V solar setup – 50W panel and 2x 100Ah batteries 12V LEDs and 12V flourescents (LED is much better than flourescent so these will be replaced soon)
Bosch AA+ rated 220V fridge
Chest freezer 220V
1800W of solar panels
5KW of generator.
So 8 months down the track we have not had to change much. Power usage is modified so that all of the high power drawing appliances run during the day. So for instance we still run a standard top loading washing machine, we just wash in cold water. Power tools are no problem, since you rarely use them for a long time continuously. The microwave oven can only be run during the day. The electric toaster is also no problem, as it draws about 1000W, but only for 3 minutes.
The fridge and freezer are on a timer so they only run during daylight hours. We have an electrical outlet on the same timer circuit with which we charge all cellphones, tablets etc during the day. It makes no sense to charge batteries from other batteries.
Because the cycle depth of the batteries is inversely proportional to their lifespan, I try to keep the batteries as fully charged as possible. I have set the inverter to kick out if the batteries drop to 50%, but this has only happened once. I run the generator from time to time keep the batteries topped up, like on cloudy days or if I am doing a lot of welding for instance. The odd bit diesel is currently our only power expense so it has been very worthwhile going this route. It was expensive to install, but now power is essentially for free!