Ken’s House 2025

Ken’s House

My wife Corinne and I started our sustainable journey by installing an induction cooktop when we put an extension on the house in 2006. At the time, the choice was gas or induction, and the latter seemed much more environmentally friendly and easier to clean.

Then, in 2014 we installed 3 kilowatts of solar power on our back roof. This reduced our power bill by about half.

The next step was to deal with the heat problem in the house during summer. We decided to install insulated rollershutters on the upstairs windows and on the east-facing door and window downstairs. This dramatically reduced the temperature on hot days. We found we only needed to use air conditioning very occasionally, and heating almost never.

The next few steps occurred after I retired in 2019. I started working on a voluntary basis for the climate movement, but soon realised that Corinne and I were not living very sustainably. We decided to make some changes to our lifestyle.

The first thing we did was replace our gas hot water system with a heat pump. We disconnected the gas and found ourselves saving about $600 a year. The heat pump should pay for itself in about 5 years – fewer if our children were still living at home.

We then made the decision to buy an EV. By ditching our old gas-guzzler, we found ourselves saving about $3,000 a year on fuel and maintenance.

However, I was annoyed by only being able to charge at home when the sun was out in force, and only in the mornings (our solar panels being shaded after midday). At other times, I had to wait for a Jolt charge point to come free so I could grab some free power. (Jolt gives you seven free kilowatts a day – enough to take you about 45 kilometres.) We decided to put 10.5 kilowatts of solar on the roof of our garage, which faces east and west. This allowed us to charge the car at any time of day. It also cut our power bill to near zero.

The final step (thus far) in our journey was to add a 13.5 kilowatt battery, allowing us to operate without resort to the grid. We are now completely self-sufficient in energy, saving about $2,000 a year on our electricity bills. Soon I will be setting up as a virtual power plant (VPP), allowing me to ‘bank’ power in the day and sell it into the grid in the early evenings, when the feed-in tariff is much higher. That is how I plan to pay off the battery long before it reaches its use-by date.

So that is our sustainability journey. In going down this path, we have tried to prove that it’s possible to save money and save the planet all at the same time. So please come and see for yourself on Sustainable House Day. I’m happy to answer any questions you might have.