Wednesday, February 15, 2017

Thermal, wind and demand forecasting failed in South Australian Heatwave: AEMO

AEMO have released their preliminary report into the loadshedding and blackout of 90,000 south Australian residents and businesses during the extreme heatwave on 8 February.

In their summary of the event AEMO outline three main causes for the failure to match generation to demand. They specify that supply was rapidly changing in the period prior to the peak at 18:00, but the problem came down to:

  • Demand was higher than forecast
  • Wind generation was lower than forecast, and
  • Thermal generation capacity was reduced due to forced outages

When you analyse the report it becomes clear there was available capacity (Pelican Point 2) that could have been brought on line to meet the demand, but the market based processes of AEMO failed.

It is important to emphasise here that Adelaide and most of South Australia on Wednesday 8 February was experiencing extreme temperatures in the middle of an exceptional heatwave. Climate scientists have been predicting that heatwaves would get more intense. This sort of extreme heat event is in line with their predictions.

Adding to the extent of the issue, AEMO ordered at the evening peak at 18:03 100MW of load shedding to balance supply versus demand, but it appears SA Power Network shed 300MW, much more than was required.

I reported initially on this event the day after, on February 9: AEMO orders South Australian #heatwave blackout while Gas turbine remains idle.



Extreme Temperatures


Let's look at the Mean maximum temperatures that occurred for South Australia for 8 February:



The north of the state is hotter during summer, so the temperature anomaly gives us a better idea of the extent above average maximum temperatures. Here is the Maximum Temperature anomaly chart for South Australia for 8 February:




The extreme conditions were or should have been well known to AEMO, and the risk that more extreme temperatures than forecast were possible, thus increasing electricity demand.

It seems temperature forecasts 24 hours ahead were 4-5 degrees below the actual temperatures of the day.



AEMO should have ensured the availability of all potential generating capacity during the morning of 8 February to meet the extreme conditions.

But, of course they couldn't because we have a market for energy generation with bids from private suppliers to supply power. The capacity for Pelican Point 2nd turbine to supply power to the grid was unknown. It needed time (up to 4 hours) to come on line. This should have been investigated much earlier in the AEMO process.

By the time the communication with Engie ocurred at 17:39, there was simply no time available. Engie responded by 18:01 that this turbine could be "available to synchronise by 1900 hrs and then be at full output by 1945 for a 4 – 8 hrs run time."

But that was too late for the peak demand crisis (LOR3) that was declared at 18:03.

In extreme heat conditions failures in thermal generation equipment are more likely, and this is what we saw in South Australia. There was a reduction of 153MW of thermal generation capacity. This was more than the shortfall of 100MW from close forecast wind capacity.



Wind generation forecast and actual is quite interesting.

The wind generation forecast 24 hours ahead was actually fairly close to the actual generation, but AEMO relied upon higher intermediate wind forecasts. Perhaps they should have relied upon the 24 hour forecast as a minimum?

This choice by AEMO resulted in shortfall of up to 100MW from wind generation at 18:00.



Here is what the SA Energy Minister said:



and the Apology from SA Power Networks for being heavy handed in 60,000 cutomers that shouldn't have been blacked out:



Here is South Australia's Liberal Party trying to spin the blackout with a quote about Pelican Point availability. This is part of the Liberal Party newly declared war on state renewable energy targets.



The Liberal Party highlight that the Pelican Point Gas turbine 2 (165MW) was noted as a pre-existing outage, "Market participant bid as unavailable; confirmed unavailable at 1739 hrs with minimum start time of four hours."

Government of South Australia media unit replied with:



which comes from AEMO market sequence of events in their report:
"18:01 - Engie informs AEMO that if directed the off line unit could be available to synchronise by 1900 hrs and then be at full output by 1945 for a 4 – 8 hrs run time. AEMO determines the unit will not be available in time to restore power system security."

Both quotes are correct, but context is all important. Engie calculated at 6pm that the minimum fire up time could be as short as 1 hour 45 minutes.

The important question is why didn't AEMO seek confirmation of reserve generation capacity earlier and have the ability to then manage any fire up time.

Utility scale solar thermal with storage needed?


Looking at the supply mix in South Australia for 8 February what would improve the mix is more solar generation time-shifted into the evening peak. Single axis solar farms could supply part of this need.



But much more effectively solar thermal with storage would be a powerful addition to the generation mix.

I visited Morocco for the UN Climate conference in November 2016. On my travels I got to see from a distance the Noor solar power station complex they are building. Noor 1 is already complete, a parabolic trough type Concentrating Solar Thermal power plant of 160MW capacity with 3 hours of (molten salt type) storage. That would have been more than enough to balance the supply and demand equation in South Australia, and emissions free.

The Ouarzazate solar power complex isn't reliant on one solar technology, but is 4 modular systems, 3 of which have dispatchable storage capacity. Two of these systems are Parabolic trough, one using a dry cooling system to reduce water use, the third one is a solar tower system, and the last a solar PV farm. Three separate storage systems will be used with 3 hours, 7 hours and 8 hours capacity.

Imagine if there were a similar solar power complex at Port Augusta with a 600MW capacity. Some of those gas generators called be permanently put on stand-bye.


Solar thermal the lost election promise


If you remember back to May 2016 and the election campaign, the Liberals promised to help fund construction of Port Augusta solar thermal power station, according to the Adelaide Advertiser.

Environment Minister Greg Hunt told the Advertiser at the time, “We have set out when we laid out the Clean Energy Innovation Fund that our number one priority in Australia would be a comprehensive solar thermal plant in Port Augusta.”

US based company SolarReserve have a proposal to build six 110 megawatt solar thermal plants in the state's north using molten salt storage technology. Thousands of jobs would be created during construction. A similar-sized plant the company built in Nevada cost about $US700 million, and it is building further plants in China and South Africa.

The sites proposed for the plants in South Australia include Port Augusta, Leigh Creek, Roxby Downs, Woomera, and Whyalla. With all new technology, getting the first plant built and running is the major hurdle and would require financial assistance from either ARENA or CEFC.

An alternative proposal from Australian startup Solastor, chaired by John Hewson, involved a 170MW, $1.2 billion project. It is a modular approach involving parabolic mirrors focussing on central towers with graphite heat storage.

A solar thermal plant with storage would help stabilise renewables in South Australia adding energy security, and provide needed jobs to the Port Augusta community. Once built, they are essentially fuel free and emissions free.

But there hasn't been a peep out of Josh Frydenberg or the Prime Minister since about the solar thermal proposal for Port Augusta and South Australia.

Daniel Spencer from RePower Port Augusta said in a statement “Gas either couldn’t take the heat or the supply had been sent overseas, we need a new synchronous 24 hour solar thermal plant to be built in Port Augusta to back up SA’s world leading clean power.”

“South Australia was sweltering last week as was most of the country as global warming continues to drive heatwaves we need investment now in 21st century power sources like solar thermal in Port Augusta,” Mr Spencer said.

The Repower Port Augusta Alliance has developed solid proposals to build up to 6 solar thermal plants and 95 wind turbines in the region which would create 1800 jobs, and ensure energy reliability and security.

“South Australians are waiting for solutions and building solar thermal in Port Augusta has been on the desks of the Premier and Prime Minister for months. The Federal Government called it its number one clean energy priority before the election. It’s time to see the action to back it up” Mr Spencer said.

“The South Australian Government’s power purchase and the Federal Government’s clean energy agencies must be used to invest in this 24 hour solar solution for South Australia. The longer the Federal Government spends politicking over this issue, the longer it will take for solutions to be built.” Mr Spencer said.

The South Australian Government is presently tendering for 75 percent of it's energy needs in a Power Purchase Agreement. The question arises, will Solar Thermal at Port Augusta offering dispatchable power be chosen? Energy Minister Tom Koutsantonis provides some hope that solar thermal is still in the running.