Household energy assets

Supporting energy system reliability

In a place with as much sunshine as WA, solar energy is abundant – and we need to manage it in a way that works for everyone.

• The challenge: With solar being a renewable but sometimes unpredictable source of electricity (such as when there’s cloud cover), and as the uptake of solar increases, we need to make sure the energy system stays balanced. When rooftop solar systems generate more energy than homes and businesses can use during the day, the excess has to go somewhere to keep supply and demand balanced across the system.
  
  
• The solution: Excess solar can be directed to a home battery or into the energy system to be used by initiatives like our big batteries and Virtual Power Plants. As our renewable energy transition unfolds, we’ll continue directing excess solar to keep the SWIS stable – and other household energy assets have an important role too.

Solar facts: The evolution of solar in WA

• Over 40% of homes across the SWIS currently have rooftop solar.
• It’s estimated that 70% of homes across the SWIS will have solar by 2033.
• When solar was relatively new to WA, feed-in tariffs for rooftop solar generation were excellent incentives to encourage the uptake of solar – but WA’s energy landscape has changed. 
• We need electricity from large-scale generation to provide a reliable supply of electricity day and night.
• However, too much excess solar generation feeding in to the energy system can create system instability. 
• Rooftop solar generation needs to be balanced to ensure the SWIS can handle even more solar energy exported to the energy system in the future.

How does rooftop solar impact system reliability?

• Solar is a sustainable source of generation, but it can be unpredictable. Imagine a suburb where most homes have rooftop solar systems – and then the clouds roll in. Whenever this happens, generation may cease and these homes all need to draw from the energy system at the same time.
• More rooftop solar means fewer homes and businesses need to draw electricity from the SWIS during the day but demand goes up again once the sun sets and everyone gets home to use their air conditioners and appliances.
• Keeping up with fluctuating supply and demand puts pressure on the SWIS, which can create system instability. 

This effect is known as the Duck Curve. If it’s not addressed, it could potentially lead to widespread power outages in WA at times the SWIS can’t cope with high demand.

Exploring solutions for a renewable energy future

Our focus is on supporting energy reliability and new technology which will enable our energy system to handle the increasing amount of energy exported by rooftop solar systems. We’re working with the State Government and other industry participants to explore the solutions we need for a renewable energy future.

• Initiatives: Our batteries in Kwinana and Collie are helping even more homes and businesses connect to renewables, as we can now store some of the excess solar generation to use in peak periods. Virtual Power Plants such as Project Jupiter help to coordinate excess solar energy.
• Products: We can now reward customers when they shift their consumption from peak to off-peak periods by providing lower rates through our time-of-use products. This means you could potentially save on electricity costs while contributing to a more reliable energy system. We’re working on new products to offer a range of options and benefits to help you get the most out of your investment in household energy assets.