Australia is a world leader in rooftop solar – Queensland leads with close to 30% of rooftops equipped with solar installations, and Australian Capital Territory not far behind. Prices for PV systems have almost halved in six years, and with electricity prices still rising, more and more households are choosing to generate at least some of their own power.
The first thing to consider is what you want to gain from adding solar and/or storage to your household or business. Are you just looking for a way to reduce your electricity bills? Or do you feel the need to be more self-sufficient and have a backup in case of power outages? We’ve prepared a list of questions to consider when selecting the size of a solar and storage installation.
How energy independent do you want to be?
You might like the idea of being completely off-grid and self-sufficient, but this is expensive to set up and, honestly, unnecessary for most households. At the other end of the scale is just installing enough solar to keep your expensive peak-time electricity use at a minimum – for most households, the most cost-effective option.
Other levels of energy independence could include:
- Summertime surplus, winter self-sufficiency
- Summertime self-sufficiency, winter grid reliance
- Self-sufficiency for energy peak periods
- Some self generation during energy peak periods
Of course, the greater the amount of solar and storage capacity needed, the greater the upfront costs. However, over long time frames, large systems are more economical per kWh.You should consider how well-connected you are, how likely you are to get power cuts and how badly a power cut would affect you when choosing your desired level of energy independence.
How much energy do you use and when?
While you can get a small (depending on the state) return from feeding solar electricity back to the grid, most of your returns will come from consuming your own solar energy rather than relying on expensive peak time power. We recommend self-consumption rates of at least 30%.
This table gives the recommended solar size for self-consumption rates of around 40%. Keep in mind this can vary significantly based on location factors such as solar panel orientation, tree cover and hours of sunlight – contact us for a more personalised consultation!
|Household Daily Energy Consumption||Recommended Minimum Solar System Size|
|5-10 kWh||< 2 kW|
|11-15 kWh||3 kW|
|16-20 kWh||4 kW|
|21-25 kWh||5 kW|
|26-30 kWh||7 kW|
|31-40 kWh||7+ kW|
Sizing battery storage is a more complicated affair. Many factors are involved – how much energy independence do you want? What is your daily energy consumption? Do you consume more energy during the daytime or night?
If most of your energy consumption takes place during prime sunshine hours, you may only need small amounts of storage. For someone who consumes most of their energy at night, you’ll need a hefty storage capacity to be able to keep the midnight oil burning. A rule of thumb to use as a starting point is a battery storage capacity of half your daily energy consumption – this should cover peak time use and a little extra.
Want to know more about how to select the right size solar and storage system for your needs? Australian Smart Group install solar panels, battery energy storage and smart meters – and we’re always available to answer your questions.