New windfarms in South Australia will face tougher technical standards, amid concern the state's heavy reliance on intermittent renewable generators has left the electricity grid prone to collapse.
The new standards have been recommended by the Australian Energy Market Operator (AEMO) to the Essential Services Commission of SA (ESCOSA), which is inquiring into the licence conditions for windfarms, and other technologies which use inverters to connect to the power grid.
Interim conditions will require new thermal and renewable generators to be capable of providing additional services, which contribute to the stability of the grid, including frequency control.
Generators must also be able to ride through some voltage and frequency disturbances, and help power system restoration after a widespread blackout.
The role of renewables in last September's statewide blackout has faced intense political scrutiny.
AEMO found a failure of windfarms to ride through voltage disturbances contributed to the catastrophic chain of events which caused the blackout.
It also found relatively low thermal generation at the time of the blackout resulted in a higher rate of frequency change when the Heywood Interconnector from Victoria failed.
"AEMO's interim advice is that the high proportion of non-synchronous intermittent generation in South Australia justifies having additional or tighter technical standards than those that currently apply under the national electricity rules," ESCOSA said.
Primary aim to 'prevent further statewide blackouts'
Many of the stability characteristics required under the new regulations are already inherently provided by coal, gas and hydro generators.
But ESCOSA chief executive Adam Wilson said until now the same characteristics were not required of wind farms.
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"Some of them may be producing the services we're seeking to require," he said.
"Some new investments may require additional plant or additional software to do this. We are taking advice from the Australian Energy Market Operator and understand this technology is available.
"The question is the cost-benefit analysis, which we'll have to undergo in finally imposing conditions later in the year."
Mr Wilson said the primary aim was to prevent further statewide blackouts.
"That's certainly our intent in imposing these conditions," he said.
ESCOSA appears to have adopted some of this thinking in granting a licence last month for a 100-megawatt windfarm near Jamestown in the upper north of SA.
The licence for the Hornsdale windfarm 2 was granted with additional conditions, requiring a wind generator to provide frequency control ancillary services to the national electricity market.
Renewables not a problem, Premier says
Despite changes ordered by both state and federal regulators, Premier Jay Weatherill denied a high proportion of intermittent renewables in SA threatened grid stability.
Two reports on South Australia's state-based Renewable Energy Target (RET), published for the Premier's Department in May 2009, warned grid stability worries would potentially constrain growth of renewable energy penetration beyond 20 per cent in SA.
The state later adopted a 50 per cent RET, but with no active mechanism to achieve it.
Independent senator Nick Xenophon said the state Labor Government had been foolhardy.
"If we listened to those reports, we wouldn't have increased the level of renewables in the absence of what was recommended in those reports," he said.
But Mr Weatherill denied the warnings were a concern.
"We have been thinking about it. We've been implementing changes as we go," he said.
"There have been a number of changes to the way in which we run the national electricity market and the evidence is manifest.
"We've had eight years of the operation of the system and there hasn't been a blackout as the consequence of the increase of renewable energy."