South Australia is currently experiencing an overabundance of solar energy. With customers able to export 5kW (single phase) and 15kW (3 phase) of solar power, the state's power grid is facing voltage rises and reverse power flows. This excess power, flowing in the opposite direction to the grid, is causing issues for transformers in substations.
Imagine you're at a party with a giant bowl of punch. Everyone at the party has brought their own juice to add to the bowl. But as more and more people add their juice, the bowl starts to overflow.
This is similar to what's happening with solar panel systems in South Australia.
In South Australia, many homes have solar panels on their roofs. These panels capture sunlight and turn it into electricity, which the homes can use. But often, these solar panels make more electricity than the home needs. So, the extra electricity is exported back into the grid.
The current limitations are 5kw for single-phase households, and 15kw for 3-phase households.
The problem is, there's so much energy being added to the grid that it's starting to overflow, just like the punch bowl at the party. This overflow can cause problems like voltage rises, which is like the electricity getting too strong. It can also cause power to flow in the opposite direction to what the grid was designed for, which can cause trouble for the transformers in substations, which help distribute electricity around the state.
Who are SA Power Networks?
SA Power Networks is a key player in South Australia's energy sector, responsible for operating and maintaining the state's electricity distribution network. The company is committed to supporting the growth of rooftop solar in the state, despite the challenges posed by the rapid uptake of solar energy.
SA Power Networks is actively investing in a range of measures to double the amount of solar on their network by 2025 and support the state's target of 100% net renewables by 2030.
What is Flexible Exports?
Flexible Exports is a solution designed to manage the growing amount of solar energy being fed into the electricity grid. The rapid uptake of solar energy has led to some parts of the electricity distribution network becoming overloaded, especially during times of high solar generation. This can cause voltage issues for all customers and can mean solar customers’ inverters trip off or ramp down.
To address this, SA Power Networks has introduced Flexible Exports, which uses smart, internet-connected inverters to adjust the amount of solar energy being exported to the grid based on the network's capacity at any given time. This means that during times of high network capacity, customers can export more solar energy, and during times of low capacity, the amount of energy exported is reduced.
Fixed vs. Flexible Exports
Under the Flexible Exports scheme, customers can export between 1.5kW and 10kW per phase, depending on the network's capacity. This is a significant increase compared to the fixed export limit of 1.5kW per phase that was previously in place in areas where the network was significantly overloaded with solar energy.
However, what that also means is SA Power Networks has control over your inverter. During summer, when solar production is high, SA Power Networks has the capability to remotely throttle or turn off the export of solar back into the grid.
This innovative approach, enabled by modern, smart, internet-connected inverters, has been initially introduced as part of a trial.
The Flexible Exports Trial
Over the past 18 months, SA Power Networks has been trialling a new approach in 35 suburbs to manage solar overload.
These suburbs in SA are:
- Glenelg South
- North Brighton
- Seacombe Gardens
- Bellevue Heights
- North Haven
- Sheidow Park
- Hallett Cove
- Oaklands Park
- Somerton Park
- Happy Valley
- O'Halloran Hill
- Coromandel East
- Old Reynella
- Torrens Island
- Coromandel Valley
- Trott Park
- Craigburn Farm
- Largs North
- Outer Harbor
- Dover Gardens
- Park Holme
- Eden Hills
- Mitchel Park
- Reynella East
The company introduced new connection options for new and upgrading small embedded generation solar customers. These customers could select from either a reduced permanent fixed export option of 1.5kW per phase or a Flexible Exports option, where their export limit would vary up to 10kW per phase, based on the network's capacity in their area.
Expansion and Deadlines
From July 1, 2023, onwards, SA Power Networks plans to expand this approach to all homes in South Australia. Customers signed by June 30th 2023 with PVSEG (PV Small embedded generator) approval will be considered before July 1.
They will have until September 1st to install their solar system and will still be considered a legacy system, able to export up to 5kW at single phase.
The Future of Solar Inverters
Not every solar inverter on the market is ready for dynamic export. Only a handful of inverters are compatible with the Flexible Exports system.
However, Go Sunny has been proactive in this regard, having already installed the most flexible ones in South Australia.
While the Flexible Exports initiative by SA Power Networks is a commendable step towards managing the solar overload, it's important to tread with caution. There's a potential risk that this could lead to a slippery slope of reduced oversight.
If energy retailers, who have to pay customers for the power they feed back into the grid, exert influence over SA Power Networks, we could see a future where export limits are reduced to zero.
This would mean that in 2-3 years, customers could be generating solar power that they can't export, effectively giving them less return on their solar investment. It's crucial that as we navigate the path towards a more sustainable future, we ensure that the benefits of renewable energy are accessible to all, and not compromised by commercial interests.