Minimum demand FAQs
Minimum Demand is the lowest level of energy demanded from the grid at any point in time.
Low demand typically occurs during daylight hours in autumn and spring, on cloud-free sunny days, when temperatures are mild enough that large energy consuming devices such as heaters, air conditioners and pool pumps aren’t turned on and rooftop solar is generating the greatest amount of energy.
When these days fall on a weekend or public holiday, when offices and large industry are off and aren’t using power, there is a risk that demand levels can drop to extreme levels.
Under these conditions, AEMO who is responsible for whole electricity system instigates critical measures required to maintain to the security of the power system and stability of the electricity supply in the South West Interconnected System.
Check out AEMO Factsheet: Minimum Demand for more information.
We’ve been transforming the grid to enable greater connection of renewables, particularly rooftop solar. However, on occasions the electricity system can be put under stress when demand is extremely low.
In spring 2022, Western Australia’s Minimum Demand records were broken four times over two weekends.
As reported by Australian Energy Market Operator, on Saturday, 16 October 2022, WA recorded 626MW of demand around midday, and at the time rooftop solar provided an estimated 74% of the underlying demand. To put this into context, the power system has a recorded maximum of 4,000MW and an average demand of somewhere around 2,000MW.
The intermittent and uncontrolled nature of solar generation presents challenges to the way AEMO balances and maintains the security and reliability of the power system, especially on mild sunny weekend days. See the AEMO Factsheet: Minimum Demand for more information.
Minimum Demand is also commonly referred to as low load or system low. Check out AEMO Factsheet: Minimum Demand for more information.
In March 2019, the State Government launched Western Australia’s Energy Transformation Strategy, a comprehensive program of work provides a vision to facilitate greater amounts of low-cost, low-emissions renewable generation to be connected to the SWIS, while managing the emerging risks to the network and power system. It’s focused on improving the resilience of the energy system, particularly through practical initiatives that address Minimum Demand challenges.
Western Power is playing a significant role to deliver: Distributed Energy Resources (DER) Roadmap, Whole of System Plan (WOSP), Foundation Regulatory Frameworks and SWIS Demand Assessment.
With our customers both consuming energy and now supplying energy, we’re changing the way we manage our network.
Western Power is working with AEMO and the State Government to minimise the impact of low electricity demand and support the ongoing solar uptake by customers and our community as we transition to a renewable future. To do that, we’ve implemented new measures and using new technologies and approaches to facilitate the growth of renewable power on the grid including:
- community batteries
- virtual power plant trial - Project Symphony
- mini-pumped hydro system trial
- microgrids.
We’re working with WA Government, Energy Policy WA, AEMO and Synergy to transform our energy landscape to make it more renewable and help decarbonise WA.
Minimum Demand conditions are a permanent feature of how AEMO manages the South West Interconnected System (SWIS) due to the continued growth of rooftop solar. This is not exclusive to Western Australia as any electricity system providers throughout Australia and indeed the world have been tackling the effects of Minimum Demand.
Given the distinctive features of our island system, with no interconnecting transmission systems to assist with demand management and stability issues - the technical and operational challenges faced is unique.