In Australia’s current climate of extreme weather and bushfires, businesses participating in demand response are playing an important role in maintaining system security and stability for all energy users.
Businesses participate in demand response via a third-party aggregator who supplies their combined energy load to AEMO when called on in response to a grid need. There have been multiple, significant grid requirements from December 2019 to February 2020.
Demand response was called on between Thursday January 30 and Saturday February 1 to support the grid each day. The cause was a combination of extreme weather and fragility of the transmission lines and network supply assets – particularly after bushfires, heat, smoke and damaging winds and storms.
Enel X, an independent, global demand-side energy aggregator, responded to AEMO’s requests for demand reduction from its customers across those three days, in both its Reliability and Emergency Reserve Trader (RERT) and frequency control ancillary services (FCAS) portfolios.
By responding with its customers’ aggregated load, commercial and industrial businesses powered down for up to four hours via RERT, providing 30MW to the grid. This helped to reduce length and severity of the emergency situation when the grid was under threat.
On Friday January 31, storms damaged six transmission towers in western Victoria, causing a trip to the main interconnector transmission line between Victoria and South Australia. This caused the grid’s frequency to drop. FCAS providers were called on by AEMO to immediately stabilise the frequency and avoid widespread blackouts.
That same day, large parts of Victoria and NSW already facing bushfire conditions also experienced extreme temperatures that caused price spikes during the late afternoon and evening peak demand period.
Providing grid support
At the end of December last year temperatures across the NEM soared above 30 and 40 degrees, placing immense pressure on the grid. This was exacerbated by widespread bushfire conditions, particularly in eastern Victoria, the unavailability of large generating units at Loy Yang and softening of availability from wind and solar farms during the peak evening period.
When the main transmission line between Victoria and NSW tripped due to the bushfires, the result was substantial loss of supply into Victoria and AEMO issuing a “Lack of Reserve (LOR) level 2” notice to the market.
While Enel X’s customer portfolio was significantly impacted by bushfire hazards, as well as operational constraints given the time of year, a total of 70 sites responded to AEMO’s RERT activation by powering down as much load as possible from 6-9pm.
On Saturday January 4 the transmission line trip caused a separation event between NSW and Queensland and the rest of the NEM. As a result, the grid’s frequency rapidly dropped in both states.
Enel X participated in three FCAS events, when the grid’s frequency dropped below its normal operating band. Businesses across NSW, Queensland, Victoria and South Australia curtailed load in response, helping to return the grid to its normal operating range. This also helped avoid generators tripping as a result of dangerously low frequency.
Everyone has a role to play
Across all events, a combination of cold storage facilities, water utilities, data centres and industrial gas processors helped to provide crucial contingency response, taking some pressure off the generators who were operating at an elevated output as they struggled to meet supply.
Enel X expects additional demand response events before summer is over, depending on the weather, particularly with the transmission tower damage in Victoria which will take several weeks to repair. The events support grid security and resiliency, providing a quicker and cheaper alternative to new generation.
Businesses suited to demand response programs range from agribusiness to hospitals, water corporations, retail shopping centres, data centres, industrial manufacturing and more.
Across Australia and New Zealand, Enel X manages about 400MW of customers’ energy load to provide relief to the grid and energy market in response to very high demand or energy pricing. Bloomberg New Energy Finance recently cited Enel X as Australia’s largest VPP in a 2019 report.
Rando Yam is manager of flexibility operations and Zac Hardie program manager of flexibility operations at Enel X Australia & New Zealand.