Home Page
  Home  |  Contents  |  Forum
Email    Bookmark    Print

Living Off Grid. Page 1 | 2 | 3 | 4

Back to page 2.

Hot Water.

For hot water I built my own solar hot water system. The 2 heater panels and a 300 liter tank were picked up from various 2nd hand dealers, and I built the controller with bits from eBay. All up it cost me about $500, but you can buy a reasonable new one for around $3000 plus. The water tank still has its heater elements, one near the top and one at the bottom. The bottom element is for off peak heating, the one at top is a boost. If it was overcast for a couple of days, I could connect the generator to the top element for 30 minutes till the thermo switch cut out, giving me enough hot water for a couple of quick showers and washing dishes. The hot water system has been a bit of a challenge, lots of leaks and things to learn, but its now pretty reliable. Important note, you need to get the tank water temperature over 60 degrees Centigrade to kill any Legionnaires bacteria. But you also need to install a tempering valve to stop the hot water taps releasing water over 50c.

The hot water solar panel stand has a roof tilted to face north to capture more sun, and doubles as a storage shed.

My hot water tank has a few extra layers of insulation to keep the heat in. Its surprising how much heat leaks from the tank, and adding insulation helps keep the water warm at night, and saves costs if you heat from the grid. The easy way to test how much heat leaks is to wrap a layer of insulation around the tank, and put you hand under the insulation next day. The heat you feel would have escaped if not for the extra insulation.


My water is tank water, and I have 4 tanks and 3 pumps to feed various taps. Over 45,000 litres all up. I have 240 m2 roof space to collect rain water, plus I pump water up from a creek for watering the garden, lawn, etc. I seam to have ample water, so don't need a water bore at this time.


Nothing special here, designed by an engineer and put in by my plumber. The size was based on the number of bedrooms, and as my house could accomdate 5 people, the septic was designed to suit. There's the underground tank, and a couple of evaporation trenches which are bacially pipes with lots of little holes, about 30cm underground. The system takes care of itself, just dont flush anything that wont disolve and break down, and restrict the fats and oils you wash down the kitchen sink.


For cooking I used a microwave and gas cook top, later adding a gas oven. Electric heating for long periods needs to be avoided at night or on overcast days, its very wasteful of energy. Typically at night I use my gas stove, microwave, electric kettle, rice cooker, etc. Appliances like the microwave and kettle draw over 1,500 watts, but are only run for a few minutes. Rice cookers ( bread makers, small toaster ovens, etc ) are usually less than 500 watts, so can be run for much longer. Electric fry pans, ovens, grills, etc user over 2,000 watts, for long periods, so not a good idea except during the day when you have ample sunshine.

Thing is, my system could happily power these high current loads like a fry pan or grill, but at a cost to the battery bank. The more you drain the battery bank each night, the shorter its life. So by being kind to your batteries, you can expect to dramatically increase their life, and reduce your living costs.

I love my gas cook top and oven. The cook top was picked up at a local swap meet for $70. The oven, a Westinghouse, was bought new from the local Betta Electrical outlet in Pittsworth, near Toowoomba. At around $1050, modern gas ovens are more expensive than electric, but use little gas, don't smell, and cook great! The gas lines were installed by a licensed plumber, and I feed the system with a 9kg gas bottle. The 9kg bottle lasts about 6 months with normal daily cooking.

My fridge is nothing special, I've had it for over 10 years and its been good. Provided you don't leave the door open, its power consumption has never been a concern. At times I've run 2 fridges when I have guests staying over. If your looking for a new fridge, its power usage should be a important consideration.

12v System

I also added a secondary power system built from spare bits and pieces I've picked up over the years. Its a 12v system, using a bunch of old big industrial Nicad batteries, a couple of 70 watts 12v solar panels, charge controller and 300 watt BP Sine wave inverter. The inverter has enough grunt to run a small water pressure pump, which is used to water the garden, wash the car, etc. The 12v system also supplies 12v to a few LED lights in the workshop, the solar water heater controller, workshop radio, etc.

Next Page.

© TheBackShed 2011