Households in remote areas can obtain much of their electrical energy needs from renewable energy power supply systems, which, (depending on local conditions), may contain solar cells, and/or a wind turbine. A battery bank is used to store the energy for use at night and other times. Most systems also contain a diesel, petrol or LPG powered generator to meet their power needs during periods of high-energy use or when solar or wind is not available.

        Many homes not connected to the grid rely on fossil-fuelled generators. They are expensive to operate and noisy to run and must be kept loaded to prevent damage to the motor. Therefore, generators usually are used only to provide power for a part of the day. In such situations, a household-based renewable energy power supply will give a consistent 24-hour power supply and may well be cheaper than the electricity grid.

         The initial cost of renewable energy systems is higher than fossil-fuelled generators, therefore there is a need to minimise power by confining the use of electricity to non-heating applications and by using energy efficient appliances. For example, various models of refrigerators vary in energy consumption from about 1,000 watt-hours/day (for a 5 star model) to about 3,100 watt-hours/day (for a 2 star model). Also, a solar passive designed house can greatly reduce the energy required for heating and cooling. Visit www.energyrating.gov.au for more information on selecting the most efficient appliance for your application.

        The cost of a renewable power supply system depends greatly on the daily energy (watt-hour) requirements, and that is found by multiplying the power (in watts) consumed by each appliance by the number of hours it is used on average each day. For example, using compact fluorescent lamps (they use only one fifth the energy compared to incandescent lamps), a household's entire lighting needs can usually be met with about 300 watts-hours of power. A reliable system to supply the energy requirements for a home with lighting, a normal family-size freezer/refrigerator, washing machine, television, stereo and a few other low-power appliances would likely cost between $25,000 and $35,000. For homes with requirements to run in addition to the above example say, a large freezer, plus longer run times for normal appliances may have to spend between $35,000 & $60,000; even higher if Airconditioners are to be acommodated in the house. Current Government rebates are available for 50% of the cost of new equipment and installation. Download the guidelines here. Download the Pre-purchase application form here.

Homes with substantial short-term energy requirements (large power tools, welders etc.), can usually meet these needs by operating a generator for short periods during peak load times and using a renewable energy system to provide the convenience of 24-hour power for general household usage. A Back-up battery charger is also a requirement for when the sun does not shine for more that 3 days.

Cooking, room heating and water heating require a lot of energy, and are not normally powered by renewable energy systems. For these requirements it is much more economical to use other energy sources. Options include LPG for cooking, space heating & water heating. Solar for water heating is another option (especially with the Government rebates available for this energy sector).

           Furthermore, it is usually not economical to size renewable energy systems to provide for energy intensive functions which are only undertaken for relative short periods of the year (such as air-conditioning). Such needs are most economically met using the generator when required. However, if you are building a new house, it is cheaper and more efficient in the long run if you can make use of the proper orientation (positioning) of the house on the site in order to minimise heat load into the house, together with appropriate insulation in the roof & ceiling so that you do not need an air conditioner.

           I can estimate your likely energy consumption by calculating the total number of watt-hours per day of energy that will be used. Just request a load assessment worksheet from me, (by fax, email or download it here), fill it in, and then return it to me at P.O. Box 7959 Toowoomba M/C 4352 for an estimate of the cost of your system based on your figures. We can then discuss ways and means to lower the costs if necessary, by using more energy efficient appliances, such as the Vestfrost range of fridges & freezers etc.

 I would be happy to discuss your requirements in person at my office, provided you made an appointment, as often I am out actually doing installations. I can also show you photos of installed systems (in your area), which shows you what is possible as far as the location of panels, batteries etc.

          Basically, I recommend that you have your house wired by a licensed electrical contractor just as if you were going to connect to the electrical Grid system, i.e. all 240 Volt wiring for the power outlets and light fittings. 

            Following this I come along with all my solar equipment and install everything in a suitable place and  "plug your house into the SUN".   No electricity bills. No power outages.

Photos below show Architect Graham Osborne and wife Sally with their partially completed Passive Solar designed home at Boonah South-East Queensland. Ten Sharp 165 Watt Modules charge a 48-Volt Battery. A 3500 Watt Latronics Sinewave Inverter converts power into 240 Volts single phase.