Australia’s Electricity Market Operator has found that Horsham and Ararat’s existing power lines would start to experience issues if the Wimmera generated more than 50 megawatts of electricity.

The Ararat Wind Farm, currently under construction, will have a maximum capacity of 240MW when completed, and the proposed Kiata Wind Farm’s capacity will be 30MW.

The Wimmera’s power grid would only offer ‘limited network access’ if power generation in the region approaches 400MW.

The market operator’s annual planning report stated that the connection of Ararat Wind Farm would place the Ballarat–Horsham 220 kilovolt transmission line at its thermal capacity under peak wind conditions.

‘Thermal capacity’ refers to how much heat a power line can absorb from electricity transmission before it starts to lose its tensile strength and sag towards the ground.

A power line’s thermal capacity can be boosted by reinforcing poles or upgrading transformers, but it comes at a cost of money and transmission interruptions.

Mr Broad said the rise of renewables had created a need to ‘double build’ the power grid to be able to send electricity in both directions.

“The question we have got to ask ourselves, if we are going to have affordable electricity, is how do you build the grid to provide base load to everyone and yet capitalise on renewables?” he said.

“Take Horsham or Mildura for example: you have got to have the grid that’s going to deliver the base load for those two towns.

“You then put renewables about - that’s fine, that’s a good thing- that supplements the power from the base load but then you get increased demand from those cities, more houses, more industry.”

Mr Broad said the same centralised power generation versus distributed power generation had occurred when the State Electricity Commission designed the grid in the late 1920s. 

The market report stated that due to growing interest in renewable energy,generator applications for connecting into the distribution network were increasing.

“Some distribution networks will at times supply the transmission network, potentially causing performance issues, as the networks were not designed to cope with flow reversal,” the report stated.