Open Letter to the Prime Minister of Australia
OPEN LETTER TO THE PRIME MINISTER, AND TO THE LEADER OF THE OPPOSITION.
We are a group of retired scientists and engineers in Queensland, and we are alarmed at the direction our country is being taken through your respective policies, which are virtually identical, on renewable energy. Our names are listed here. We have studied this issue for years now, and we have here outlined the serious defects in your energy policy, and asked some questions which have thus far remained unanswered.
Energy Policy. By far the greatest risk to Australia’s electricity supply is the false belief that renewables (wind and solar) can be a like-for-like replacement for dispatchable fossil fuelled generators. They are not, and can never be. A one-MW wind or solar plant does not replace a one-MW coal plant. Not even close. Solar plants will produce electricity on average at 20% of their installed capacity. They produce power for little more than eight hours per day and none at all at night or on rainy days. Wind plants can be expected to produce electricity on average 25% to 30% of installed capacity, but output can be as little as 2% or as much as 70% with little warning.
Media reports in June this year referred to a “wind drought” across Southern Australia resulting in wind production being “40% below the previous corresponding period”. This is a problem but masks an even more intractable false belief; that an energy grid can run on averages. It can’t, because energy consumed has to be generated in real time. Just one example of that wind drought: at 2.20 PM on 5 th May this year, all the wind farms in Australia (4400 MW installed capacity in WA, SA, Vic, Tas and NSW) were producing just 121MW. (That’s 4400 MW capacity generating only 121MW). In fact for May and June this year this was not uncommon. Large high pressure systems over southern Australia meant little or no wind for weeks at a time.
The grid has to meet demand every minute of every day. AEMO can and does order fossil fuelled plants to produce electricity. Clearly it cannot do so for wind or solar. Just imagine Australia with a largely renewable energy system — it is night time so no solar power is being generated, and the whole of Southern Australia is dominated by high pressure systems (this is not unusual) and wind is producing at only 2% of installed capacity! To date dispatchable fossil fuelled generators have been able to shoulder the load but as dispatchable capacity is retired this may no longer be possible, with disastrous consequences.
On the face of it the answer is storage, either battery, pumped hydro or molten salt. This brings us to the next false belief; that storage is some sort of magic pudding. The capacity of current storage technologies is miniscule compared with daily demand. Australian grid demand varies between 18,000 MW minimum and 30,000 MW maximum. Over 24 hours this works out to about 600,000 MWh per day. The Tesla battery being installed in South Australia is said to be the world’s largest and to hold 129 MWh fully charged. This may be enough to support the local grid for a short time until dispatchable capacity can be started, but an unimaginable number of Tesla batteries would be necessary to maintain grid supply for a day or a week, or even longer in the worst case.
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