Two reports in the Adelaide “Advertiser” caught my eye. One was headlined “Hydro to keep our electricity pumping” and the other concerned another billionaire who wants to save us – “Gupta pledges to fix SA’s energy debacle”. At least he was right in describing it as a debacle.
The hydro article lists five proposed “pumped hydro” schemes and lists capacity and output for each, but fails to mention how much water might be needed and that the schemes are nett users of electricity rather than generators.
Mr Gupta says he will install “one gigawatt of dispatchable renewable energy” which will power his Whyalla steelworks and have a bit left over for the rest of us. The articles confuse power with energy; the reporters constantly claim we “use MW”. Clearly they have no idea what they are talking about. The critical question is how long Mr Gupta’s “one gigawatt” will produce electricity for.
It is interesting that there are two mutually exclusive terms used; renewable and dispatchable.
I thought I would analyse the 5 hydro proposals to see how much they can provide as a percentage of average daily consumption, how much electricity they need to re-fill the dams and how much water is needed to run them.
The following analysis is based on a head difference of 150 metres. This is a bit generous but I do not have access to enough detailed topography. Remember, Mt Lofty is only 711 metres high and it is the second highest peak in SA.
The table below lists the 5 schemes and shows installed capacity, water flow required in cubic metres per second, stated output in MWh, the time each needs to operate to achieve that output and the total quantity of water in Megalitres for that time period.
|Output MWh||Hours||Total water, Megalitres|
|Highbury||300||226||1,200 (see * below)||4||3,260|
(*: Cannot confirm this number but have seen it somewhere).
South Australia’s average daily power consumption is 31,600 MWh so the total output of the 5 schemes above can contribute 21% but they require the equivalent of 24% to pump all that water back uphill, so they are nett energy users, not generators.
The total cost quoted for the 5 schemes is $1.86 billion and the result is a deficit in power available for consumption. We are told that they will use “spare capacity” from wind farms and perhaps some solar installations to provide their pumping power. Today at noon wind was producing 1.25% of the total grid load. In SA we managed half of that, running at 150 MW). This is common during summer and lots of wishful thinking will not change it. My recent article on a proposed solar farm indicated the miniscule amount they can provide.
Adelaide’s average daily water consumption is about 550 Megalitres per day so the schemes require about 33 times this amount to be stored in “turkey’s nest dams”, an appropriate word. Where will this come from in the “driest state”?
If we consider a dam of 100 hectares surface area the depth of water needed for the largest scheme is 5 metres. Intakes must be submerged below the minimum level otherwise they will suck air so the full depth will be even greater. Also evaporation of around 3 metres per year needs to be considered.
There is some naive idea that these schemes can be a bit “agricultural”, just get some gear and build a couple of “turkey’s nests”, get some pipes and turbines and Bob’s your Uncle. The reality is very different, having been involved in a couple of hydro-electric schemes myself.
There is also the added cost of transmission and the complexity of running these things on the fly whenever we are a bit short of juice.
The point that is never mentioned is that the destruction of the Playford B and Northern power stations removed 760 MW of generating capacity, 76% of “one gigawatt”, and it was available every day of the year, night and day, windy or not. None of the proposed schemes can come within a bulls roar regarding economy and reliability and neither can wind and solar. We should remember that when we hear all the bullshit sprouted about “renewables” and recognise that it is all political and has no technical merit at all.
All this pain is to “reduce emissions” when there is plenty of evidence that it is a pointless exercise and that we actually do not have a problem called “anthropogenic global warming”. How do we get off this train to the madhouse?