As Australia's net zero transition threatens to stall, rooftop solar could help provide the power we need

• But progress is challenged by the scale required, community resistance to new infrastructure and connecting all that new renewable electricity to the grid.
• The roadblocks facing large projects present an opportunity to ramp up the contribution of small-scale technologies in the energy transition.
• So, how large a share of our electricity needs might rooftop solar provide?

Why rooftop solar presents a challenge for the grid

• But AEMO does not dispatch power from rooftop solar, which is either used on site, or flows into the grid independently of AEMO’s control.
• This isn’t usually a problem, since AEMO keeps the grid balanced by forecasting how much rooftop solar is being generated.
• Grid security can also be challenged when unexpected events trigger the safety settings of rooftop solar systems and cause them to disconnect.
• So how are we managing the three challenges of rooftop solar: lack of controllability by the market operator, uncertain behaviour during unexpected grid events and impact on network voltage?

Ways to manage and expand rooftop solar

• The good news is that standards introduced in 2020 provide more sophisticated ways of managing solar through more gradual voltage response, and by requiring systems to ride through major disturbances rather than disconnecting.
• Some networks have also developed solar-friendly ways to cut off surplus output “dynamically”, meaning only at times when they have to.
• While necessary in the short-term, if unchecked they will reduce our ability to realise our rooftop solar potential.

Getting smarter about when we use power

• To make such a change, consumer electricity prices are a potential lever.
• Solar customers already have an incentive to use electricity from their own rooftop systems, because they pay more for grid electricity than they are paid to sell solar back to the grid.
• In these cases orchestration schemes, often called “virtual power plants,” are an option.
• Good governance arrangements and meaningful stakeholder consultation are essential if Australia is to maintain the momentum of its people-powered energy transition.

• Baran Yildiz receives funding from the Australian Renewable Energy Agency (ARENA) and the RACE for 2030 Cooperative Research Australia.
• Dani Alexander receives funding from the Australian Renewable Energy Agency and the RACE for 2030 Cooperative Research Centre.
• Mike Roberts receives funding from the Race for 2030 Cooperative Research Centre, the Commonwealth Department of Climate Change, Energy, Environment and Water, and Essential Energy.