Australia is going through an exciting energy transition that, in part, is being driven by customers who are continuing to invest in distributed energy resources (DER) such as rooftop solar.
In South Australia, more than one in three customers have installed rooftop solar, with total capacity now exceeding 1.8GW – a vast resource of the same scale as the state’s typical electricity demand of around 1.5GW.
SA Power Networks, recently named by the Australian Financial Review as among Australia’s top five innovative companies in the energy, mining and agriculture sectors, has developed a suite of solutions that will enable greater DER uptake and the continued transition to a decarbonised and decentralised energy system.
Mark Vincent, General Manager Strategy & Transformation at SA Power Networks, said the utility is committed to supporting the decarbonisation of the state’s energy system and sees the energy transition as a tremendous opportunity to create an affordable, reliable, low carbon energy system that will deliver significant value for its customers and community.
“We have reached the stage where rooftop solar will soon be able to meet all of our state’s energy demand, making South Australia the first
gigawatt-scale system in the world to be faced with the challenges of a highly decentralised energy supply. That means we are working as a virtual test-bed for networks and energy markets in Australia and overseas,” Mr Vincent said.
“Over the next decade, we can expect the amount of solar connected to our network to double, as well as almost a gigawatt of residential energy storage and over 150,000 electric vehicles. In total, over 5GW of resources will be operating on a power system designed for 3GW.
“The key to making it all work is flexibility,” Mr Vincent said. “There is a lot of interest in what we’re doing, particularly the development of innovative flexible connection options for DER. “Flexible connection arrangements, where customer and network equipment work together, will be central to maximising the value of the future energy system.
We think they will become a standard approach nation-wide. Given our immediate challenges, we’re prioritising the introduction of our new ‘Flexible Exports’ connection offering for solar.”
In simple terms, instead of implementing a lower fixed export limit in constrained areas of the network (as some other networks have done), SA Power Networks has developed a flexible export solution that allows solar exports up to 10kW depending on network capacity at any given time.
The flexible exports trial
The ‘Flexible Exports’ connection offer is being developed as part of a $4.84 million ARENA-funded trial, with SA Power Networks and Victorian- based AusNet Services partnering with industry-leading inverter manufacturers, Fronius, SMA, and SolarEdge, and energy management software company SwitchDin, to develop the technical capability needed to offer solar customers flexible rather than fixed export limits.
Brendon Hampton, Manager Network Strategy at SA Power Networks, said, “Flexible export limits offered under the trial will enable more customers to connect to solar and also provide greater solar export opportunities throughout the year.”
“With Flexible Exports, solar exports are automatically adjusted to maximise the amount of solar that can be connected and exported to the electricity grid. “Based on our modelling, we believe customers will be able to export up to 10kW, 98 per cent of the time, which will provide significantly more access to the network than even our standard fixed 5kW export limit.”
Initially, SA Power Networks is offering Flexible Exports in areas served by the Sheidow Park substation in Adelaide’s southern suburbs. More than 46 per cent of households in the area have solar and the local network is reaching its limit to support more solar connections at the current fixed export limit of 5kW.
However, the network is only congested at rare times (e.g. mild, sunny days in spring). Mr Hampton said the Flexible Export option had only been made possible through working closely with trial partners and extensive engagement with the solar industry.
“We recognised that introducing this new option was a significant change for customers and for the solar industry,” Mr Hampton said.
“Establishment of our Solar Industry Reference Group meant we could work through all the challenges with solar retailers and installers to achieve a marketable solution which is now being tested in the real world.”
The challenges
The rapid growth of solar has created several challenges for networks. First, in localised areas, solar exports can exceed the local network’s capacity, resulting in issues such as rising voltages and inverters switching off in response.
And, when there are large amounts of solar energy being exported into the network at once and there is low energy demand, it can overload major assets and create issues for managing security of supply.
Currently, solar customers in South Australia are able to export the excess energy they create back into the network with a fixed limit of 5kW per phase. But in areas with a very high take up of solar, SA Power Networks is faced with the need to reduce export limits to 1.5kW for new connecting customers to avoid exceeding network capacity.
Instead, SAPN will offer customers a choice of either a smart new Flexible Exports option or a flat 1.5kW limit for the whole year. Energy Networks Australia (ENA) has congratulated SA Power Networks on its world-leading trial. ENA Chief Executive, Andrew Dillon, said the project, introducing flexible export limits, had far-reaching implications for solar customers across the country.
“This is the future – a smarter, more flexible power system. It is fantastic news for South Australian customers,” Mr Dillon said. “We are in the early stages of this new technology, and Flexible Exports is a world-first that will help us accommodate more solar on our network,” Mr Vincent said.
“We expect that once we have proven the technology and validated the customer experience that this will become a standard offer for new solar customers in South Australia from mid-2022.
“The widespread adoption of Flexible Exports and introduction of some other initiatives we are putting in place will help achieve our goal to double the amount of solar we can accommodate on our network by 2025.”
