Home Fat Power Station
A four horse power diesel engine driving a 2kVA alternator. A double pole changeover switch selects the house power source as either generator or grid power.
The diesel engine is a McDonald horizontal water cooled single cylinder which is at least fifty years old. The engine is fitted with two fuel tanks. One with canola oil for cold starting and a second larger one which is heated by the cooling water. The larger tank holds fat (solid at room temperature animal and vegetable oils). It takes about half an hour running on canola oil to heat a cold tank of fat before the fuel can be switched over.
The water cooling system is connected to an old hot water system providing 300 litres of hot water storage. Two 200 litre fat storage drums are kept in a liquid state by circulating the hot water through heat exchanger pipes inside the drums.
The alternator is a two kilowatt single phase Dunlite with a Dunlite control box/regulator. This is also at least fifty years old. The engine runs at about 500 rpm to provide 240Vac at 50Hz. The engine has an electric starter and electric shutdown which is surprising considering its age and basic design.
Both the engine and alternator were salvaged from a farm dump. Neither had been used for at least ten years to my knowledge but they required only a few hours work to get them up and running (a tribute to old-style Australian engineering).
I have routed the exhaust system through a water bath, through the centre of my hot water tank and outside to an old car muffler. The water bath is heated by the exhaust and is used to warm 20 litre drums of fat before filtering. The engine is situated about 15 meters from the house and can?t be heard from inside. When the engine is not under load there is barely any visible exhaust but as the load increases the BBQ flavoured white smoke increases.
The power output of the alternator is not high enough to run all the appliances in the house, particularly heavy inductive loads such as the washing machine so when the load exceeds output the changeover switch has to be switched back to grid power. The changeover switch is a two pole three position switch with centre off which gives absolute isolation between the grid and generator supplies. The changeover switch is conveniently located inside the house. Of course any electrical wiring of this nature should be completed by suitably qualified people. There can be disasterous consequences if things go wrong.
I plan to install a larger engine and alternator, around 6kVA, when finances allow.