When my wife and I decided to buy a suburban block in Brighton, in the outer reaches of Brisbane, to build a home that we had designed ourselves, the economics of not being connected to the electricity grid was something we thought was worth exploring.
After thinking things through two years ago, and doing some rough calculations, we decided to take the dive into the unknown.
We couldn’t be happier.
We had young children and I particularly did not want my children growing up and blaming me for the climate woes worsened by global warming. We ordered a Kia EV6 when it was time to upgrade the family car. We chose that car because of the ability to draw 16A from it by just plugging a lead into its 77kWh battery.
When we demolished the dilapidated asbestos ridden house that we bought, we had Energex disconnect the power and physically coil the power line to the power pole where it remains.
We built the our current house without a grid connection. On the odd occasion when we needed power on site the Kia EV6 was our generator. We knew we did not want an air-conditioner or heating so we insulated the place well beyond the national construction code requirements.
We are only 200 metres from the ocean and are therefore blessed with the sea breeze. Our off-grid solar system cost $32,000. That included 36 (440W) panels (a bit over 15kW). We are running an 8kW Victron inverter with three pylontech 5000 batteries.
A Victron EV charger was installed which allows the Kia EV6 to be charged automatically from excess solar when the house batteries sit at a pre-determined level (currently 80%).
When building, we often drove the car to the build site as the car charges up to three times faster on the off-grid setup as opposed to using the 10A power point in the rental that we had (which also had solar panels).
If for some reason the house batteries are ever exhausted, the system does support our earlier research and we can plug a lead into the Kia EV6 and run that lead into the generator socket for the house.
We can therefore run the house off the car battery which is presently five times bigger than our house battery. If we were to ever run the car battery low and exhaust the house battery the car can simply be driven to a DC charger to bring power back to the house.
In terms of hot water we are using a Steibel Eltron heat pump hot water system, it heats at 10:00am every day. I knew the big test in terms of whether the house would be a success without a connection to the electricity grid would be based upon the power draw at night time.
We have now lived in the new house for four months and on average use only 25 percent of our house batteries at night time. Irrespective of cloud cover our house batteries have charged to 100 percent everyday.
The end result is this – We don’t have a power bill; the car charges for free and we have not needed to use a charger away from home in the last four months; the car has a range of just over 600 km and the battery can be charged 60 percent on a single sunny winter’s day; the heat pump cools the air in the utilities room which is blown by the fan on top of the heat pump into the home gym.
Clearly, the economics of going all electric are improving. If industry does not realise that residential solar makes sense economically, and takes measures to reward consumers to stay connected to the grid, I imagine more consumers will disconnect from it and less people will pay for the expenses involved in maintaining the poles and wires.
In circumstances where parts of Australia are already charging consumers to export solar power, why would I remain connected to a grid I no longer need?
I feel somewhat irresponsible for not being connected to the grid as I know our excess solar may be utilised by the main grid if it had sufficient battery capacity. I really hope the regulators and the energy retailers can move with the innovation that is occurring.
If they don’t, those that can’t afford the poles and wires maintenance may end up having to pay for the policy failures that do not incentivise people like me to remain connected to the grind.
Note: Author’s name has been withheld at their request.
