AEMO: WA demand met as rooftop solar grows

Existing and committed generation resources alongside demand side management capacity is sufficient to meet forecast peak demand in the South West interconnected system (SWIS), according to the Australian Energy Market Operator (AEMO).

AEMO’s Wholesale Electricity Market Electricity Statement of Opportunities (WEM ESOO) shows electricity demand is forecast to grow slowly throughout the 10-year outlook period, underpinned by lower economic and population growth, and the continuing uptake of rooftop PV.

The latest analysis shows homeowners in the state are set to install 134MW of rooftop PV per year on average, equating to a total rooftop PV generation capacity of 2273MW by 2027-28.

One in four Western Australian households now have rooftop PV installed.

“With equipment and installation costs for rooftop PV falling, we are anticipating Western Australian consumers to continue to take control of their power consumption,” AEMO executive general manager WA Cameron Parrotte said.

This WEM ESOO illustrates the role increasing rooftop PV is playing within the SWIS, flattening both operational and peak demand over the 10-year outlook, and contributing to a reduction of the Reserve Capacity Target (RCT), which sets the capacity required to meet peak demand, a worst-case contingency, and frequency keeping requirements.

“Based on the 10 per cent Probability of Exceedance (POE) scenario, the Reserve Capacity Target for the 2020-2021 Capacity Year has been determined as 4581MW, which is a decrease from the 4660MW target in 2019-20,” Mr Parrotte said.

“The decrease in the RCT is due to a relatively flat outlook for peak demand (an expected annual increase of 0.6 per cent).

“It also factors in the increased levels of rooftop solar generation, together with forecast lower economic and population growth compared with the previous year’s forecast.

“While there have been recent retirements of some fossil-fueled generators, new renewable generation capacity is enabling the RCT to be met within the defined reliability standard, and with significantly lower excess capacity than historically recorded.”

The growth of renewable generation in Western Australia is an example of the changing generation mix, which is in line with changes observed in other electricity systems, including the National Electricity Market (NEM) of eastern and southern Australia.

“Wind and solar generation by their very nature are intermittent, and with rooftop solar in particular, the generation availability is not visible to AEMO in real time, and cannot currently be controlled or coordinated to respond to variances in the system,” Mr Parrotte said.

“However, projects like the Western Australian Government’s market reform, the upcoming WEM reviews, and further infrastructure development in the SWIS, are all well underway.

“These important developments are focused on ensuring consumer expectations for reliable, secure and affordable energy are addressed.”