How will residential batteries change the operating conditions of distribution networks in the future? And what happens when most homes have one?

The Victorian Government’s Solar Homes program is proving extremely popular, with Victorian households taking up the rebate offer to install solar and batteries in their homes as a means of better controlling their energy bills.

Part of a broader program aimed at energy efficiency and lowering energy bills for Victorians, it provides financial support for the installation of solar panels, solar hot water systems or batteries on 770,000 homes across the state. But what happens when every home has a battery?

 

Batteries – the natural firming alternative

Residential batteries – a battery in your home – can play a critical role in storing the energy produced by rooftop solar or other intermittent renewable generation. While energy generated from solar photovoltaic (PV) systems at home must be used at the time it is generated, batteries provide the ability to store that energy and use it when it’s needed, to help households lower their energy bills.

 

Planning for the future

AGL has been an advocate of batteries, across large scale sites, in the home and in businesses. We believe the future of Australia’s energy will be delivered from renewable sources backed by flexible storage that is smart and affordable.

As residential batteries are a relatively new technology, there’s still a lot to learn. For example, how will high penetrations of residential battery systems change the operating conditions on our distribution networks in the future?

The Centre for New Energy Technologies (C4NET) in partnership with the Victorian Department of Environment, Land, Water and Planning (DELWP) supported an RMIT University study into the electricity consumption behaviour of households with batteries to investigate their interaction with low voltage grid conditions and forecast how those conditions might change in the future as more batteries are installed.

AGL was invited to support the study by providing 12 months of granular, de-identified, residential battery operational data. As a provider of Virtual Power Plant services, we welcomed the opportunity to share operational data to help inform the study.

The project objective was to study the electricity consumption behaviour of households with batteries and investigate their impact on the distribution network. This is particularly insightful for identifying the benefit of batteries on the distribution network and recognising the potential network services they can enable when installed en masse and orchestrated..

 

The key findings

Battery behaviour supports the distribution network

The study by RMIT based on the data provided by AGL and a range of other industry participants showed that batteries can be beneficial for distribution networks and act as a natural ‘firming’ resource to soak up excess daytime solar and reduce evening peaks. Among the findings, the study specifically identified:

• Household batteries reduce PV export by at least 20% in peak sun hours on cool days, helping to balance the generation from rooftop PV systems, and potentially enhancing network hosting capacity.

• Peak evening power imports for households with batteries (i.e. 6pm to 10pm) are significantly reduced (60%) on mild temperature days.

Potential network services opportunities

The study also found that under certain high penetration scenarios, that coordination of battery operation – like a virtual power plant – could provide network support services and help to maintain network operational conditions within their normal operating envelope.

The Energy Security Board (ESB) is working on integrating DER assets into the electricity system and providing opportunities for consumers, through 2-sided markets, to participate in the energy market by offering up excess and/or stored generation in their homes. This finding is important in identifying potential new opportunities for households with solar and batteries in their homes.

Read more about the study here or find out about our battery and solar bundles.