In 2015 I moved into a new house which at the time was using a whopping 85 kWh/day on average in winter and not getting below 45kWh/day across most of the year. I straight away installed a large 10 kW solar pv array. A lot of this power was being exported to the grid during the day and we were still using a lot at other times. I wanted to try and use more of the power I was making, this posts tracks the journey through that process.
Australia has one of the highest residential solar PV installations in the world with over 1 million systems installed. They’re installed by home owners with the goal of reducing their electricity bill, saving money or getting a good return on their investment. How well this works is totally dependent on how well the solar power system is performing.
Any of the following this can go wrong which reduce output of a solar system:
Across Australia most new solar installations are subject to tariffs which pay the owners as little as 1/4 or less for their excess power that they export to the grid during the day than they are charged for using the same power through the evening hours.
Installing a battery system in your home allows you to instead store this excess electricity and use it yourself, avoiding the high tariffs.
The apps listed below let you track the path of the sun on any day of the year from any location. This allows you to understand how much sun will hit your building and assess the effects of shading from neighbouring buildings or trees.
Reducing your electricity usage starts with understanding where you’re using your electricity.
Start by making a list of the consumption from each device in your home using an electricity usage monitoring device. Keep in mind that some devices will consume a relatively constant amount of electricity over time (eg Toaster, Television, Laptop charger) whilst others will be more variable (eg Fridge, Washing machine, Rainwater pump). For those which are constant a spot check will be sufficient, for those which are variable leave the monitoring device contected for a period of typical usage over 24 hours.
Photovoltaic solar panels where ever possible should form part of any green renovation.
What size installation?
- Residential roof mounted photovoltaic systems typically start at 1.5kW and range up to 5kW
- Ideally you would install a system which had an average annual production the same as your power consumption.
- The ATA have created Sunulator, a spreadsheet tool allowing you to model the financial effect of different size solar systems. The tool includes the ability to import historical usage data from your energy provider and makes allowance for various electricity providers pricing tariffs.
- Before deciding to install larger arrays, consider how much the equivalent spend would allow you to reduce your consumption by? For example installation of solar hot water, energy efficient lighting, draft sealing, thermal curtains, solar air heaters.
Every home uses electricity which by default is overwhelmingly in Australia, is derived from burning fossil fuels. You can’t avoid using electricity but you can minimise your usage and ensure what you do use is produced in a sustainable way.
Whilst electricity prices in Australia have remained relatively low the general consciousness of it’s consumption has also.
A number of devices now exist which allow you to view and monitor your electricity usage in real time.