Runs on Sun (and rain) 2024

House Notes – Runs on Sun (and rain)

Less CO2, more H2O! 

This is a retrofit of a double-brick and tile home built in 1971. The orientation is north–northwest by north, and the home was built to be solar passive. Over the last fifteen years, the passion has been in taking progressive steps towards making the property and transport more sustainable, reducing the carbon footprint and aiming to achieve carbon tiptoes.

The metre-long eaves on the north side of the house provide shade to the windows in the summer, whilst allowing warming sunshine inside in winter.

The roof tiles were originally a dark-green colour. These have been treated with Insulpaint in an off-white colour, which has significantly reduced the summer temperature in the house.

The 5.5kW solar system is grid-connected, exporting clean renewable energy. The 5.8kW solar system is hybrid off-grid. It does not export to the grid. When the sun is shining, this system can power the house and/or charge the electric vehicle/s and/or charge the storage batteries (22kWhs). When there is no solar power, the batteries can supply the house load. If there is no solar or battery power, electricity can be taken from the grid. Over the last fifteen years, over 100,000kWh of renewable energy have been exported to the West Australian grid (the SWIS). Over the last eleven years, I have not had to pay an electricity bill.

The all-electric vehicles mean that I do not buy petrol. Garden and power tools ( lawnmower, etc ) are re-chargeable battery electric.

With a total roof area of 240m2 (including all sheds/outbuildings), rain water is harvested via custom made, extra capacity gutters (to cope with tropical type storms). To try to keep the water as clean as possible, the following systems are fitted: leaf gutter guard, double filter screen rain heads, ‘first flush’ units, and ‘Maelstrom’ cyclonic type filters. Total storage capacity is 112,000L. This is used for bush fire defence via roof top sprinklers, vegetable garden, fruit trees, general garden, and, after further filtration, for kitchen and drinking.

Part of the vegetable garden incorporates salvaged baths on plinths. Shade-cloth protects the vegetables in summer, but allows in the winter sun. The whole vegetable patch is enclosed in wire mesh to keep vermin, especially possums, at bay. Kitchen scraps, vegetable and grass cuttings are all composted. There are two mature fruit trees – lemon and nectarine. Young and productive fruit trees include mandarin, orange, apricot, almond and apple.

This home demonstrates that solar PV can be good for both the Pocket and the Planet.

This home is supported by Sustainable Energy Now.