Authority warned on windfarm overload

Adelaide Advertiser
Friday 26/6/2009 Page: 3

SOUTH Australia must be careful about becoming too reliant on wind energy, the Essential Services Commission has warned. SA was already second only to Denmark in the proportion of electricity generated by wind, the commission said. By the end of next year capacity would exceed 1000MW - equivalent to nearly a third of peak demand. "The Commission remains concerned with the long-term safety and reliability of the electricity system in SA," it says in a paper setting out a draft decision on licensing windfarms.

Commission chairman Pat Walsh said the problem was manageable but SA had to impose tougher licensing conditions than applied in other states. "Wind generators are intermittent - output rises and falls depending on whether the wind is blowing," he said. "If you've got a large proportion of that type of generation in your overall system, that can have unintended consequences on security and reliability, unless precautions are taken."

The commission said SA had the highest installed capacity of wind generation and wind energy made a bigger contribution to meeting electricity demand in SA than in any other state. "(Therefore) the Commission considers a measured and cautious approach to licensing wind generators remains warranted," it said. This was why the commission had made a draft decision imposing a tougher licensing regime in SA, Mr Walsh said.

Licence conditions included technical standards so SA windfarms would be more robust and better able to withstand problems such as a spike or sudden drop-out in the system - called "fault ride through". Mr Walsh said while capacity was high, windfarms generally only delivered about a third of that on average over a year and could only be relied on for about 10% of their capacity to meet peak demand.

There was already 739MW of capacity and another 128MW under construction. Licence applications for a further 193MW were being considered - taking the total to more than 1000MW. This compares with the summer peak demand for electricity in SA in 2007-08 of 3172MW and in 2008-09 of 3450MW. The commission says it is possible capacity would increase to 2400MW or 2700MW by 2020.