Did renewables or coal fail in Victoria?

| February 20, 2019

There has been much commentary about renewables failing during the power crisis in Victoria. In fact it was the opposite, wind and solar performed as they had during the 10 days leading up to January 25th, it was coal that failed.

First some background. All power systems have gas plants as backup and most have diesel as well, because speed of response and low capital cost offset the lower operating cost of coal or nuclear plants when the gas or diesel plants are used sparingly.

Gas peakers in the US for example operate an average of 4% of the time. Even in SA, over the seven days to January 30 including the heat wave, Open Cycle gas and diesel combined have operated at less than 10% of capacity.

In the good old days, before wind and solar were a thing, Eastern Australia had 49 GW of coal, gas and hydro to supply an average of 24 GW demand and a peak of 35 GW yet in 2009 there were three instances of load shedding, up to 1,000 MW at a time.

This year while gas and coal capacity was reduced by some 15% since the peak and the population had increased by 16% only 200 MW was shed. That was when 1,800 MW of coal was unavailable in Victoria alone.

There are two a websites OpenNEM and Anero.id which show power generation in 5 minute intervals across the NEM. From that data:

On January 24, in spite of the hottest day ever recorded in an Australian capital, SA had no lack of generation, 20,000 people were disconnected because of a substation fault not a lack of generation.

There is 3,400 MW of gas and diesel capacity in SA. Their maximum combined output together was 2,940 MW at 7PM.

By next summer SA will have approximately 400 MW of low wind specific wind turbines operating which even in last Thursday’s weather conditions will supply a minimum of 90 MW. It will also have 1,000 MW of new solar and 50-100 MW of new batteries so while the solar won’t contribute much at 7 PM the batteries and wind will easily combine with existing gas to carry the load.

SA is already a net exporter so that will only increase while gas consumption will continue to fall.

Coal and gas plants were also offline in NSW. Even though the heat in NSW was significantly less than Victoria. NSW was still unable to export power to Victoria but in fact was relying on imports from Queensland.

At 1PM on Friday at the height of Victoria’s power shortage NSW was exporting nothing to Victoria but was importing 1,300 MW from Queensland and the NSW coal and gas plants could manage no more than 82% of nameplate capacity. In contrast SA exported continuously to Victoria from 6 AM to midnight with a peak of 640 MW and an average of 460 MW.

Victoria on January 25th

1. In the month of January wind supplied 6.4% of Victoria’s power. At 11:30 on Friday it supplied 6.4% of the power.

2. In the ten days leading up to the 25th of January between 11:30 and 3:00 PM wind output varied between 32 MW and 1032 MW . Average output at 11:30 was 313 MW and at 3 PM was 445 MW. On January 25th wind at 11:30 was 421 MW and at 3 PM 465 MW. It is true that it dropped briefly to 380 MW briefly around noon but it was still above the midday average of the previous fortnight. Rather than tailing off by 5 PM it was up to 880 MW.

3. In January large scale solar supplied 1.4% of Victoria’s power at 11:30 on Friday it was supplying 2.1%. between 11:30 and 3:00 PM it varied between 161 and 248 MW. In fact peak supply was higher than the previous few days. In January 2018 it supplied nothing

4. Brown coal supplied 74.1% of Victoria’s power in January and 80% of net demand in 2018 but when it was needed it dropped to 31% at 11:30 on January 25th.

5. Over the course of the day only one of ten coal generators managed to run at rated capacity all day. Total output from 4,730 MW of capacity declined from 3,118 MW at 11:30 to 2,970 at 2:20 before kicking up to 3040 MW at 3 PM and dropping back again to 2833 MW at 6 PM when 4 units were offline. In the cool part of the day some coal units were running at 105/106% capacity but during the heat of the day when they were most needed, output from those units dropped by about 12-14%

6. In the critical 11:30-2:30 time period Lily D’Ambrosio was confident that the coal generators, which have had many millions spent on them over the last 3 years, would perform somewhere near capacity. She was mistaken. 38% of coal capacity went off line.

7. From 7AM to 9PM wind and solar combined varied between 6 and 11% of supply, vs their monthly average of 7.9%. After the sun went down wind was not less than 10%

How do we ensure it doesn’t happen again?

If we invested $1 bn in coal it will buy a single 250-330 MW brown coal HELE plant but won’t fuel, operate or maintain it. An additional $50-60 m per year it will supply about 1,400 GWh/yr. Output will be zero for an average of 300 hours per year for outages and maintenance.

One billion dollars will finance 250 MW of wind 250 MW of tracking solar and 120 MW of pumped hydro and 100MW of batteries. That system will generate 1,600 GWh/yr year and provide between 400 and 600 MW peak power on a hot day.

Output will never need to be zero. It won’t generate 100,000 tonnes of solid waste nor use 4 GL of cooling water. Annual operating and maintenance costs will be around $30 m per year.