05 Feb The Heat is on – Time for Nuclear.
In the face of record hot summers, it has become clear that renewable energy from wind and solar combined with ageing coal power stations can neither meet our peak demands nor the challenge of carbon emissions reductions.
The whole reason for a transition away from coal burning was to limit climate change. As inferred from the Garnaut report the emissions intensity of Australia’s electricity generating system needs to drop to below 50 gr CO2/kWh in order to limit temperature rise to 2 degrees centigrade.
Great hope exists that this emissions limit can be achieved with intermittent renewable energy sources such as wind and solar however this has not been achieved anywhere in the World to date and no nation is on track to verify if it’s even possible.
The extreme variability of wind power creates much of the problem. Last week’s extreme weather events have shown that carbon emissions from electricity generation remain high and even increase during these events.
The high demand started in South Australia on the 24th January. Normally South Australian wind generators perform well by World standards. Last year wind met 40% of the State’s electricity power generation. Our energy market operator, AEMO expects that wind farms will provide at least 9.4% of energy during extreme summer events. This they failed to do on the 24th January.
On that day after 3pm their performance steadily reduced until at around 11pm the wind farms produced almost nothing. By then South Australia was relying on gas and diesel for all its electric power generation together with imports from Victoria.
The impact on emissions and electricity prices was dramatic.
South Australia normally generates electricity with an emissions intensity of about 320 gr CO2/kWh or 405 gr CO2/kWh if we allow for fugitive emissions from gas and coal. That’s about 8 times higher than sensible environmental limits. It’s typical of the type of carbon emission plateau that is caused by excessive reliance on wind generation.
At 11 pm that night the emissions intensity rose to about 925 gr CO2/kWh on a par with coal burning Victoria and New South Wales. The cost of this environmental failure throughout the day was huge with an average spot price of electricity of $3,359/MWh peaking at $14,500/MWh. That’s the price people pay for having to duplicate a power generation system just in case one falls over.
Victoria’s turn came on the 25th January. Wind started the day “going gangbusters” with 1145MW – at 3am when demand is at its lowest. By 3pm wind energy was down to around a third of this value as the impact of the hot still air kicked in. By this time the brown coal plants had lost about 17% of their capacity due to mechanical problems. Wind staged a comeback in the evening before falling to zero at 11am the next day. While brown coal was doing the heavy lifting, the real backup energy sources through all these events were the predictable and dispatchable hydropower and gas.
Over reliance on gas meant that emissions took a real hit. Total emissions intensity throughout the day was around 810 gr CO2/kWh or sixteen times our required global warming mitigation target. The economic cost of these extreme weather events is very high and in Victoria the average spot price of electricity was $753/MWh and $3,378/MWh on the previous day.
Victoria and South Australia just scraped through – this time! The electricity generating sector has insufficient capacity to meet the needs of Australia’s economy. It is not acceptable to close down businesses such as ALCOA’s Portland Aluminium smelter or other industrial energy users. This is “white flag” stuff. We have effectively given up all ability to remain a viable industrial economy.
The long-term low carbon solution for South Australia and Victoria is clear.
Firstly, It is the adoption of nuclear energy and the first two GW of nuclear power plants need to be built at Portland in Victoria. This would consist of a pair of units constructed on an ideal site using sea water for cooling.
Secondly, the transmission system linking these nuclear power plants to South Australia and metropolitan Melbourne needs to be upgraded.
Thirdly, to ensure both low electricity prices and low emissions, the electricity generating system needs to concentrate on using solar PV, pumped storage, hydro power and gas plants to meet the daily peak demands. Reliable base load will be met using nuclear generated electricity.
Finally, the use of wind farms needs to be curtailed. Their lack of reliability makes them a “Trojan Horse” for the excessive use of gas power and results in market manipulation. The result is very high carbon emissions and electricity prices.