ASX-listed renewables developer Infigen Energy has revealed that generation from two of its South Australian wind farms was heavily curtailed over the month of May, due to unplanned grid maintenance.
Infigen said in an ASX release on Tuesday that production at its Lake Bonney 2 and 3 wind farms, located near Millicent, had been curtailed by the network operator during the month to allow unscheduled maintenance at a nearby transformer (work that is now completed).
As you can see in the table below, the unscheduled curtailment on electricity production for the two wind farms saw their electricity production cut nearly in half, compared to the same time last year.
The timing is unfortunate for Infigen, considering that levels of curtailment of wind generation in South Australia have been significantly reduced over the first quarter of 2019, driven by changes to network operating guidelines and increased availability of synchronous generation on the grid.
The Australian Energy Market Operator, in its latest Quarterly Energy Dynamics report said that the level of curtailment in the state had been reduced to around 1 per cent of the unconstrained intermittent generation forecast, down from record highs of around 10 per cent in the previous quarter.
In the report, AEMO said the reduction in curtailment over the first few months of 2019 had been driven by increased availability of wind and solar generation in the region, comparatively fewer periods of high wind conditions, and changes to operating guidance.
Those changes have allowed dynamic levels of non-synchronous generation – ranging from 1,000MW to 1,460MW – based on the synchronous unit combinations available.
This compared to the strict rules of the previous quarter, that limited total wind and large scale solar output to 1295MW at any one time if there are not enough gas generators available to protect what it calls system strength.
Infigen is currently in the process of installing a 25MW/52MWh Tesla battery system at its Lake Bonney wind project, to provide frequency and ancillary services to the grid, as well as to store energy, allowing for “firmed” supply for its contracts with commercial and industrial customers.
The company had originally planned to have the first stage of the battery system completed in February and the second stage in May. But as Giles Parkinson reported here, connection delays mean it is now not likely to be completed until the September quarter.