This is a draft of a chapter in the work in progress to explain why Wind and Solar power cannot replace coal and gas to provide reliable power until massive amounts of wind and solar power can be stored to use when the sun is not shining and the wind is low.
The key point is to take account of the choke point in the supply of wind and solar power. That is the lowest point, the worst case scenario. We have to plan for the worst case otherwise sooner or later large parts of the grid will go down, even whole states. How many times a year can we afford that?
It is potentially catastrophic to invest public money in windmills and solar farms before mass storage is available. The German Trifecta of Failure and the South Australian experience have demonstrated that.
The results of premature investment in intermittent or unreliable energy.
Power becomes more expensive.
The supply becomes less stable and less reliable.
The coal-fired power stations are driven out of business by subsidised renewable energy with favoured access to the grid.
This is happening in Australia and the situation will get a lot worse unless there is an effective plan to save the coal-fired power stations before any more are closed.
Two major misconceptions. One is the claim that RE has been getting cheaper and is now cheaper than coal-fired power. This can be addressed another time, the point is that the problem of the choke point applies regardless of the cost of RE.
The other misconception is that batteries and pumped hydro will solve the storage problem. This can be answered briefly.
The $60M battery attached to the ….windfarm in SA will supply power for 20 minutes after the wind stops. It would power the SA grid for 3 or 4 minutes. Calculate the cost of batteries to support the SA grid for a few hours or a whole day.
A wall of household batteries costing 10 or 12K will keep the lights on overnight, plus the fridge, charge your phone and boil the jug but don’t do any washing or run the air conditioning, or charge the two Teslas in the garage. They might set the house on fire as well! And how long do they last?
Don’t expect a miracle from pumped hydro. The way things are going several coal stations will be closed by the time Snowy2.0 is completed, even on the current timetable. That could take x GW out of the system and how much is Snowy 2.0 going to deliver? Remember that almost a third of the power that is generated by the wind and solar farms is lost in the pumping. How sustainable is that kind of waste? The preliminary estimate of the cost for Snowy 2.0 would deliver two modern coal-fired plants and you can guarantee that the cost will blow out by many billions of dollars and the time for completion will blow out as well.
How soon can be dispense with power from coal?
The short answer is that there is no quick way to eliminate coal-fired power. Audrey Zibelman, CEO of the AEMO the Australian Energy Market Operator, conceded that coal will be in the mix for some time but where is the plan to save the coal stations?
She has claimed repeatedly that we can win the Power Trifecta by getting cheaper power and more reliability with more renewable energy in the mix. This is a remarkable claim in view of the German Trifecta of Failure.
The daily cycle of electricity use and the sources of supply in South Eastern Australia.
This is the picture for the 24 hours up to 8pm Friday 16th. This is easier to read although of course it keeps changing. Still it shows 24 hours so you can get the picture however much the details change.
1.The providers. Black and brown coal are the foundation of the supply. Brown runs at a steady level while Black rises and falls following the demand on the system. Natural gas and water (hydro) go up and down fairly rapidly as required. The supply from wind is highly variable and on this particular day it ranged from 60% down to 27% of plated capacity at the evening peak. Solar power of course comes and goes between day and night.
2.The daily cycle. There are peaks in the morning and the evening for breakfast and dinner. The evening peak is higher because in winter the heaters are on and in summer the air conditioning is likely to be turned up. The winter peak usually approaches 30GW.
3.The contribution of sun and wind at the peaks. Solar makes some contribution in the morning but none at the evening peak in winter.
The capacity problem. Managed and unmanaged load shedding
The AEMO issued a warning that a lot of capacity in the system has been lost in recent years. Some 6 or 8GW has gone in the last few years and Liddell is scheduled to close in 2022 or maybe 2023.
When the system lacks the capacity to provide the power that consumers want to use there is managed and unmanaged load shedding. First the system operator (the AEMO) contacts high volume users and instructs them to reduce their consumption. At the next state the operator blacks out selected suburbs or districts. If the managed load shedding is too little or too late the whole system or some substantial area blacks out – the whole of South Australia went for three days in 2016.
The fragility of the system is not well known. It would be better understood if the public could find out how much of the first stage of load shedding happens. There is a cost because the users are compensated and the price is paid by increasing the cost of power to users at large.
The Choke Point guarantees that Solar and Wind cannot replace coal-fired power.
The following figures address the situation at the winter peak of demand that is about 30GW after 6pm when the sun is off duty.
Supporters of RE might claim that the 6 GW of wind power that are currently being built or proposed in addition to the 6 GW existing will cover the loss of coal-fired power. Those figures come from this source and I thought that much more is impending, of course the situation changes so fast that figures are out of date by the time they are published.
Anyway, consider the amount of Wind required to replace the current supply of 18 or 19GW from coal. The other main providers are Water with capacity in the order of 5 or 6 GW and various forms of gas that add up to about 6GW and nobody is suggesting that the should go.
Now consider how much installed wind power is required to generate 18GW at the lowest point of wind supply – around 2% or 3% of plated capacity. Think of the analogy with drowning. When you are under water for five or ten minutes it does not help that for all the previous years of your life you breathed air with 20.95% of oxygen.
Even at 5% of plated capacity, a common enough reading, 18 x 20 = 360GW.
That is a scary figure compared with even the most inflated estimates of proposed Wind projects.
How much can Hydro and Gas ramp up when the wind dies?
Where is the fault in this line of argument?
Are they counting on nuclear power?
UPDATE. More figures to indicate the shortfall of wind. These are the percentage of the total load provided by wind at the evening peak over the last few days. To be fair we are not expecting wind to reach 100% because Water and various forms of gas are good for about a third of the 30GW demand. So just consider the gap between these figures and (say) 60%.
6, 2.4, 3, 2.5, 2.5, 4, 4, 5, 1, 5, 7.5, 5, 15, 16, 4, 10, 1.3, 6, 9, 7.