“Unmanaged energy”: WA gears up for solar switch-off rules, to probe Christmas blackouts

Source: Western Power

Western Australia has launched an independent investigation into a series of blackouts that struck the state’s main grid over the Christmas period and left tens of thousands of households without power during a four-day heatwave.

The outages affected communities across the state’s South West Interconnected System between December 24 and December 28, peaking on Boxing Day when 34,000 customers were left with no electricity as temperatures in Perth topped 43.5°C.

The six-week review into the outages, led by the Australian Energy Market Commission’s Michelle Shepherd, will examine how and why they happened, as well as the role of the network company, Western Power, both in its preparation for the Christmas period and its response to events.

In a statement on Monday, state energy minister Bill Johnston said the review would look into Western Power’s network and operational planning, network design, load forecasting, asset management and maintenance.

Areas on the SWIS that experienced repeat losses of power during the Christmas period, or have had a history of power issues, will also be closely examined as part of the investigation, the minister said.

Johnston did not comment on the cause of the outages in the statement on Monday, except to say high bushfire risk conditions had exacerbated the situation, delaying Western Power’s ability to carry out repairs until it was safe for crews.

A government spokesperson said the four-day heatwave, where Perth recorded its hottest Christmas Day on record at almost 43°C, caused individual feeder failures and challenges to reconnecting the grid, due to high fire risk.

“I’m pleased that Michelle Shepherd has accepted to lead this review,” the minister said. “It’s understandable how frustrating it was for the tens of thousands of customers that didn’t have power during the very hot Christmas holidays.

At the time of the outages, Western Power’s head of network maintenance, Zane Christmas, said most of the problems were load related, as households and businesses cranked up air conditioners to beat the heat.

“A lot of the faults that we are dealing with at the moment are blown fuses, all sort of excessive load I guess and given the heat it is understandable everyone’s using a lot of appliances and air-cons and what have you,” Christmas told local radio.

“I do understand the frustration, it is a fact that the network is fairly resilient but when you are in a heatwave scenario it stresses the equipment more than you would normally get.

“Ordinarily, we would be able to react really quickly and get the power back on but the additional complication of the fire danger index and the danger particularly around bushfires means we can’t re-energise and that means long outages.”

The review comes as the state’s government-owned network operators Western Power and Horizon Power navigate their grids’ rapid transition to renewables, including a huge uptake of rooftop solar power.

On Monday, the McGowan government again stressed the enormity of the state’s break-neck shift to distributed solar, with 191MW of new small-scale solar generation capacity added over the course of 2021, taking the total amount of rooftop solar installed on the SWIS to more than 1.3GW.

And while this amount of distributed solar can have the effect of slashing demand during daylight hours, it can also pose a unique set of problems for the grid, including managing fluctuations in a potentially huge amount of daytime solar supply.

“This unmanaged energy presents challenges on mild sunny days when rooftop solar generation is high and demand from the system is low,” the statement said.

To this end, Western Australia is preparing to allow the network operator to order residential rooftop solar systems to be switched off remotely as an emergency measure to keep the grid stable, with new rules around this coming into play within weeks.

The Labor McGowan government announced the solar switch-off measures in November of 2021, which it said would be used as a tool “of last resort,” for use over short periods on days when abundant rooftop solar generation sends demand for electricity to critically low levels.

To facilitate the shut-down mechanism, all new or upgraded solar systems (with inverter capacity 5kW and below) installed on the state’s main grid, the South West Interconnected System, will be required to have the capability to be remotely switched off, and back on again, starting from February 14.

The move by Western Australia to take overarching control of new residential solar systems connected to the SWIS follows South Australia’s move to do the same in September of last year, giving that state a deployable resource of up to 140MW of rooftop solar.

In a statement on Monday, the government said the measures would enable the continued uptake of rooftop solar panels on WA homes, while also helping to avoid blackouts.

“Over the past 10 years rooftop solar has increased by over 600 per cent, with 50 per cent of WA households expected to have solar panels by 2030,” said Johnston.

“These rapid changes to the energy landscape have presented a range of challenges and opportunities, which we are addressing to ensure electricity remains affordable and reliable.

“The McGowan government continues to support the uptake of residential solar, batteries and electric vehicles, and is committed to net zero carbon emissions by 2050.”


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