Acorn, some responses to your post which are my opinion and meant in the spirit of discussion, I suspect you will not agree which is fine. I support renewables to 50% however I believe there are serious problems with what has been done in South Australia which need addressing urgently. I believe these issues are being dismissed and intentionally deflected in the wider community. Here we go -
- A repair bill? I don't think so.
Yes, South Australia has over invested in Variable Generators that cannot provide the services provided by the generators they replaced and are planning to displace. Rather than address this issue SA want access to NSW generators that provide this security.
Before reacting think about what is going to happen this Spring and how high the curtailment and FCAS costs are going to be in SA.
Also consider what will happen when the Stockyard Hill, Cherry Tree and Macarthur Wind farms start producing in anger.
- A new piece of critical infrastructure that is part of the national grid? Yes
No, The Transmission Line is not critical to the national grid. It works perfectly fine without it.
The AER determination states “The net benefits of the PACR preferred option are mainly dependent on inputs and assumptions regarding future gas usage in South Australia. This is because the construction of the SA-NSW interconnector enableslower cost sources of generation (e.g. black coal generation from New SouthWales) to replace more expensive South Australian gas-fired generation that isassumed to need to run in the absence of the interconnector.”
The full determination can be assessed here: https://www.aer.gov.au/system/files/AER%20-%20Determination%20-%20SAET%20RIT-T%20-%2024%20January%202020.pdf
- Conveniently forgets to mention that the interconnector will provide excess renewable energy generated in SA to be exported into NSW.
Possibly correct however NSW is building its own Wind and Solar which will be cheaper than the older SA generators due to the “Learning curve” and supposed falling cost. The NSW solar farms also have higher Capacity factors and Wind generators and are more widely dispersed. SA may now have several “stranded” wind and solar assets building more will increase this likelihood.
VIC is and has also been adding its own VRE. The in-low of this additional supply to the proposed and existing interconnector’s will reduce the need for imports from SA.
- Doesn't highlight that the reason for this instability is that SA will simply be generating too much power.
Yes, SA will definitely have the ability to generate more electricity when it is not needed and not enough electricity when it is needed.
More VRE means more instability.
- Imagine that? A state that produces more emission free power than it needs for itself. I wonder what that will do for power prices in the future.
In a generating sense there is no such thing as Free Power. The LCOE is the cost of power, the wholesale price is the value the market places on it. If the value of power is nil then the generator is losing money, the LGC’s reduce the loss but that has also fallen because of the oversupply.
I believe Power prices will most likely continue to rise as the curtailment reduces the capacity factor and the embedded fixed costs are spread over smaller volumes. If Wind and Solar farms are compensated for the curtailment this cost will be passed on to consumers. Also the cost of the Transmission will be passed on to the consumer and increase Network costs.
If Wind and Solar farms are not compensated they will have to revise their asset values to reflect to lower price and volume assumptions. Also Curtailment reduces the claimed emissions savings. Roughly speaking I think every 1 MW of curtailment means about 0.8 to 1 tonne of CO2 savings not delivered. Curtailment for South Australia last year was roughly 345,000 MWh’s and this year after nearly 6 months it is around 210,000 MWh’s.
- Not only reducing pollution but reducing prices as well.
There will be an increase in pollution when the transmission is manufactured and constructed and also Transmission losses. To date I don’t believe the CO2 effect has been quantified or included in the project justification or emission projections. If the NSW imported power has lower emission than SA gas then emissions may reduce.
The pollution is moved from the electricity sector and reported in the mining, transport and manufacturing sectors. Some is exported overseas and inter state.
- SA has plenty of renewable resources up its sleeve and would build more if they could use it. The interconnector will enable this and could make SA an overall net exporter of power.
SA will definitely want to build more wind and solar but they can’t use it so it is pointless. The sun shines in the daytime and the market for unwanted electricity in the middle of the day has been met by rooftop solar. Storage will be promoted which adds to the cost/pollution and means the LCOE’s (for wind and solar only) are now meaningless and not relevant to future discussions or modelling.
- Rather than being a traditional net importer of fossil power which it has been for decades, the interconnector could make SA an overall net exporter of clean electricity for the east coast.
Unlikely, Fossil power is only used and needed in SA when there is low or no Wind or solar. That need is determined by the weather not the amount of wind or solar farms built. There are diminishing returns not being accounted for in the models.
NSW and VIC have to ensure they have sufficient intra-state generation to protect against islanding. They will build their own.
Some models predict 90 GW wind and solar across the NEM. In the middle of the day the solar has say 80% capacity factor which means they generate 72 GWs and demand is 23 GW. That is only one hour - seriously how many batteries are we going to build? ra
The 80% is required to meet the 41% and 30% annual average. If it is curtailed it is mathematically impossible to me the average.
- So, apart from reducing the need to switch off solar, commonly known as curtailing, it will enable NSW to reduce its reliance on fossil making the whole grid much more efficient and clean.
See above. The use of average annual capacity factors in models hides the variability of renewable generation. Wind and solar rarely operate at the capacity factor used in the models. There is hourly variation, day/night, high demand/low demand. Summer/Winter. Extreme weather, High pressure systems, Clouds, hot/cold days.
Next time someone puts an LCOE in an article check the assumptions on capacity factors and look for the Curtailment factor assumptions, then look to see if it includes the transmission cost, FCAS cost or storage component. If the assumptions are not disclosed then the number is meaningless.
The beauty now is the South Australian’s have built more than enough Wind / Solar / Batteries / Standby generators and Barker Inlet gas generator to quantify and review the experiment. The experiment was expensive however I believe it was not useless and provides an insight and perhaps a warning to other states. In my opinion it only adds value when and if the lesson are learnt and addressed.
