Mount Waverley house

Mount Waverley House solar array
Mount Waverley House solar array
OwnersJohn Poppins
LocationMount Waverley, Melbourne
TypeSustainable renovation

Summary of house features

  • Solar panels, grid interactive and batteries
  • Solar hot water
  • Rainwater tanks
  • Low power appliances, no air conditioner
  • Double glazing (planned)
Mount Waverley House solar array (rear)
Mount Waverley House solar array (rear)


For over 20 years we have used compact fluorescents where lighting is required for long hours. These have lived as long as 8000 hours over 8 years, saving electricity, money and ladder climbing. Filament bulbs are still more appropriate where light is briefly used. We are now experimenting with LED lights in the most appropriate areas.

The slate roof and brick veneer walls include a heavy duty reflective sarking and the ceiling is insulated with fibreglass, to which we have added greater depth.

We plan to double glaze some large windows in heavily used areas with low cost clear film. Heating of kitchen and living room is by gas furnace, lounge by open fire for which we grow all the wood used. In summer we use only fans, not air-conditioning.


Back in the 90s when installing computers in Jakarta and Bangkok I became accustomed to installing Uninterruptible Power Supplies as a matter of course. Following privatisation of the SECV our power in Mt Waverley deteriorated and I found a need to secure my computer supply with a battery charged by two 80 watt BP panels.

The electricity supply improved after a few years, the battery finally died and I had learnt that the expensive panels had usually fully charged the battery by mid morning and then became idle. This made clear the value of a Grid Interactive system which would enable the panels to contribute power so long as there is daylight.

In March 2007 we had 3.0 KW of PhotoVoltaic panels installed, with a 2.5 KW Sunny Boy Grid Interactive inverter. On its first day it generated 15.6 KWhr of power, far more than we use. In its first year of operation it generated 3299 KWhr (an average over 8.9 KWhr per day) saving over 4 tonnes of carbon dioxide. Its angle optimises summer generation when there is both most demand for power and most sunlight available. Mounting on a nearly flat aluminium roofed workshop created a need for some care in choice of materials and design of the supporting structure.

As at 24th July (17 months) the system has achieved 4060 KWhr and saved over 5 tonnes of carbon dioxide.


A 2200 litre tank is a few years old. As this can catch only a tiny portion of the available winter rain a 9000 litre tank is being added. To increase effectiveness of the tanks through winter we intend to use them to supply the toilets but the major usage will probably be for the garden in summer.

Hot Water

A gas boiler with a heat exchanger has served the house well for over 50 years. We have bought and are about to install an evacuated tube hot water system, Sunplus panels with 24 tubes, control system and Beasley stainless steel tank. Winter boost will then be by gas demand heater.


A weak link. We still have our 4 cylinder cars.

The advent of the carbon free electricity from the PV panels led to some thinking about local trips, particularly shopping. An electrically assisted bicycle (PowerPed Sherpa 3) has been bought to assist us up the hill (we are in our sixties) and we hope that this will reduce our car usage. It is fun, but too new to assess its impact.


The Monash Council’s 2008 World Environment Day Award for “Green Household” was presented by the Mayor in June 2008.