CleanCo marks first day by switching on pumped hydro to meet solar duck curve

The new Queensland renewable energy generator CleanCo has marked its first day of operation by switching on the little used Wivenhoe pumped hydro storage facility in the middle of the day – even though prices were not particularly low.

The 570MW Wivenhoe facility – rarely used by its former coal-focused owners – was switched on in the 12pm trading interval as more than 2,400MW of solar output, including more than 1.6MW of rooftop solar,, began to define the “solar duck curve”, where demand, and usually prices, are reduced in the middle of the day.

The move meant that prices did not go down very low, and remained around $60/MWh or more. The coal generators continued to generate, and Queensland’s considerable excess capacity was exported south to NSW.

In an interview with RenewEconomy’s Energy Insiders podcast earlier this week, CleanCo chair Jacqui Walters said the company intended to change the use of Wivenhoe, and target the duck curve, using it as a buying opportunity to fill its reserves, so it can then take advantage of higher prices at times of peak demand to send energy back into the grid.

The Queensland state Labor government, which chose to create CleanCo to operate alongside the existing Stanwell Corp and CS Energy, says the new generator will pushi power prices down using Queensland’s strengths in renewable energy.

“From today, CleanCo has 1114 megawatts of dedicated clean energy generation assets in Queensland hands,” deputy Premier and Treasurer Jackie Trad said at a media event at the Wivenhoe dam. CleanCo also operates the Swanbank E gas generator and three smaller hydro stations in the north of the state.

“Preliminary analysis forecasts CleanCo should save $70 per year off the average Queensland household power bill, through a $7 per megawatt hour reduction in wholesale prices,” Trad said.

Energy Minister Anthony Lynham described CleanCo’s entry to the National Electricity Market as the most significant development in the Queensland electricity landscape since major structural, institutional and regulatory changes more than 20 years ago.

“This will maintain Queensland’s nation-leading renewable energy growth and importantly, increase the diversity of our publicly-owned generation sources,” he said.

“And importantly, new generation means business opportunities and jobs building and running those projects.

CleanCo had been tasked with bringing on an extra 1000MW of clean energy over the next five years and will also complete the Government’s Renewables 400 reverse auction, bringing up to another 400MW of solar and wind energy and battery storage into the market Binding bids are now being sought from 10 short-listed proponents, although one has gone into liquidation.

CleanCo CEO  Maia Schweizer said in the government issued statement that CleanCo was focussed on operating its assets to generate the best value for Queenslanders.

“As Queensland’s publicly owned clean energy provider, we have a responsibility to ensure operation of our assets is socially, economically and environmentally viable,” Schweizer said. “We will use our assets to sustainably and responsibly increase supply in the electricity market.

“This means, for example, being strategic about when we draw electricity from the grid to pump water from Wivenhoe Dam to Splityard Creek Dam and when we release that water to generate electricity, making sure we maximise the value of our pumped storage asset and maintain capacity to firm other renewable sources.”