Lets be clear that the quest for net zero emissions has turned into the most disastrous policy bungle in our national history, wartime included, whether you go back to 1900 or 1788.
That can be explained by reference to the Iron Triangle of Power Supply in the electricity grid, bearing in mind to the logic of testing (or falsification, as Karl Popper called it.)
The three aspects of the triangle are:
- Continuous input of power. Adequate input is required all the time, not just most of the time or almost all the time.
- Wind droughts and especially windless nights break the continuity of input from wind and solar power.
- There is effectively no storage to bridge the gaps (despite all the talk about batteries and pumped hydro.)
Consequently the proposition that the grid can run on wind and solar power is falsified and there is no justification for the decision to contaminate the grid with subsidized and mandated intermittent input from environmentally ruinous wind and solar facilities.
Batteries can be ruled out very quickly by comparing the capacity of the biggest batteries in the world with the amount of power required to get through a windless night. Journalists don’t help by reporting the capacity of batteries in MW instead of MWh (megawatt hours) because the number of MW may be quite impressive until you realise that the flow only lasts for an hour or two compared with the 24/365 flow from a well-maintained coal plant. Scribes who report MW instead of MWh should be promptly escorted from the building with their personal effects thrown into the street after them.
More words are required to describe the inadequacy of pumped hydro to help because there are many large schemes around the world, and there are some small ones in Australia already. However I am not aware of any large scheme that runs on wind and solar alone. The largest facility at Bath, Philadelphia (US) runs entirely on coal and nuclear power to enable those plants to run continuously at their optimum output.
The Snowy Scheme: How it works
That is nothing like Snowy2.0, it just shows the principle of the upper and lower reservoir with pumps and turbines in between.
At Snowy2.0 power is generated when water runs down from Tantangara reservoir to the lower Talbingo reservoir until spare power in the grid is used to pump it back to the top.
According to the business case the upper reservoir has an active storage of 240 GL which, is supposed to be enough to generate 350 GWh of electrical energy (2000 MW for seven days.) For comparison, when it was new Liddell coal station was designed to generate 2000MW continuously.
Two highly experienced engineers in the Energy Realist team, Craig Brooking and Mike Bowden, conducted a thorough analysis of the scheme and found that it is a woefully inadequate effort.
Tantangara Reservoir has never been more than 70% full in the 23 years to December 2020. This means that there has never been sufficient water to generate the specified 350 GWh of electrical energy over 175 hours.
The long-term average storage available in Talbingo is approximately 33 GL. This volume is clearly insufficient to support 175 hours of generation, unless the water is allowed to spill which may violate the conditions of the ‘Snowy Water Licence”
The melancholy story
The scheme was announced by PM Turnbull in 2017 with an estimated cost of about $2bn. The feasibility study in 2017 predicted a cost in the range of $3.8bn to $4.5bn and the scheme was expected to deliver power by late 2024.
Nowadays it is uncertain whether the scheme will ever be completed and cost estimates (including major transmission lines and a substantial wind fleet) run up over $20 billion. The scheme depends on pumping power from a fleet of wind turbines that is almost as large as the currently installed capacity of wind power in the NEM. These additional facilities will cost in the order of $14bn, not counting the transmission lines.
The cost of power.
Bowden and Brooking modelled the system and determined that the likely cost of the power will be in the order of $450/MWh compared with the $135/MWh predicted in the business case.
Continuity of power supply
The scheme does not deliver a continuous flow of power because there is a pumping phase when water is moved from the lower reservoir to the upper level and a generation phase when the water runs down through the turbines. During the generation phase, a flow of 2000MW is specified. This is unrealistic (as noted above); it is the scale of a large coal-fired power station; but because the flow is not continuous, the total output is only a fraction of the output from a conventional power station.