A nation still drawing 18,000MW in it’s sleep can’t go solar…

I’m away, so this is a good time for Guest posts. Here Tony explains that we need lots of electricity even while we sleep. I didn’t realize our electricity needs were so high at night. The lowest power use each day is still as much as 60% of the peak. That’s the base load at 3am, and solar panels and wind farms just can’t provide it. We can burn the odd $500 billion building hundreds of solar plants, but even then, we would have to go “medieval” for about 8 hours each night. Candles anyone? — Jo

Guest post by Anton Lang


There’s a message in these two diagrams that underlies every decision about national energy.


Summer power curve - Time of Day versus power consumption (MW)


These two diagrams are the most misunderstood images in the whole debate — the Load Curves for actual power consumption. These two shown here are for the whole of eastern Australia (including Tasmania and South Australia).

The top diagram shows typical consumption for a day in mid summer (Monday 30th January 2012) and the second is for a typical mid winter day (Friday 22nd July 2011). (Usually peak winter consumption is a bit higher).

Consumption dips at 3AM to 4 AM on both diagrams  to 18,000MW. So even when asleep, eastern Australia is consumes 18,000MW of power, basically 60% to 65% of every Watt of power that could be generated (generation capacity is about equal to the peak load).

Winter power curve: Time of Day versus power consumption (MW)

That level of power is required absolutely for the full 24 hours of every day, i.e. 24/7/365. It’s the Base Load — two words here, not just one word used as an adjective to describe coal fired power plants. It’s the minimum actual physical power just to keep things running in eastern Australia.

That power is supplied by plants running flat out at 3,000 RPM day in and day out. The only time they stop is when one generator at each plant is turned off for maintenance purposes. At these times, other large scale coal fired plants supply what is now out of service. These plants are mainly those on spinning reserve, and it’s described that way because those large scale generators take anything up to days to run down correctly, and then run back up correctly. So, typically older plants are kept on spinning reserve, in other words, running at speed but not supplying power, so, when needed they are ready to come on line delivering power.

The key here is that we just can’t store electrical energy on a big scale.

Peaking Power

The extra power required above that Base Load is called Peaking Power (or Peak Power). Peaking Power is an everyday occurrence — other power plants are brought on line to ‘top up’ the power. Again, this power has to be on stand-by ready for consumption. If power is predicted to be consumed, then the grid controllers need that power already at the grid, ready for it to be drawn down by people in homes with plasma TV’s and ovens and toasters. Peaking Power is provided mainly from natural gas fired plants, which can come on line and spin up to speed within minutes.

There are two distinct peaks on that winter diagram. In the morning — breakfast, showers, turns on the heaters etc —  and then again in the afternoon and evening — when people come home and turn on the heaters, stoves, microwaves, washing machines and dryers.

Without rearranging our biological clocks, or reforming our civilization, there’s no real possibility of ‘flattening out’ the two humps.

Renewable power just cannot fill those unmovable daily time-slot requirements.

Let’s look at the Base Load. We are told that Concentrating Solar (CS) can do this, but it just cannot.

A CS power plant currently can in theory supply a maximum of 50MW, but even now the best plant in operation only provides 17MW. Let’s pretend it can do 50MW. These plants are ones that have heat retention and can supply their power after the Sun sets, but the best case year-round-average is around 16 hours a day. And in winter, when the peaks are highest, there may only be 4 hours a day when sunlight is strong enough to use.

The logistics of solar and wind don’t add up

Base load is 18,000MW, so we  need at least 360 best case CS plants. They cost around $1.45 billion each, so around $520 billion for construction — and still you have an average of 8 hours in every day without incoming power to run Australia.

Wind power can provide some power throughout the day, but their average 8 hours a day of maximum delivery is usually not the right 8 hours. In eastern Australia, the total power delivered by the 23 wind plants with 965 huge towers is still only 600MW, or around 3.3% of Base Load.

While there are people who will tell you that concentrated solar and wind power can power eastern Australia, it looks impossible once you dig down to the details.

Source for Load Curve Diagrams: Third graph on each page

Summer Jan 30 2012     http://windfarmperformance.info/?date=2012-01-30

Winter Jul 22 201     http://windfarmperformance.info/?date=2011-07-22

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11 comments to A nation still drawing 18,000MW in it’s sleep can’t go solar…

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    The Old Man

    Of course, to meet Base Load and Peaking Power, we could just build a few nuclear powered power plants.


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    Eric Anderson

    Where did all the comments go?

    (We are working on it) CTS


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    The Old Man has hit the nail on the head. If global warming was really all about CO2 then why are the AGW proponents not building and screaming for Nuclear Power Plants. Solar/wind power only increase the need and demand for natural gas. This fact alone tells me it is not about CO2 – there is another agenda. Even converted envirowhaco R Kennedy Jr. has told the ANGA and other natural gas suppliers that “Think of wind turbines as gas plants. You need to support wind power as that will increase the demand for natural gas.” (paraphrased)
    Would you throw gas on a fire? Would you throw half gas, half water on a fire? I would put out a fire with water (or CO2). The most efficient Natural Gas turbines still produce 60 to 75 percent of the CO2 of a coal fired power plant. So using natural gas, even though it is “clean” it is not CO2 free – it is like throwing 60% alcohol 40 % water on a fire. Try that. make a fire in a fire pit and try putting out the fire with rubbing alcohol. Let me know how man bottles it takes. – Doesn’t work does it?


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    Graeme No.3

    Only for base load.
    2 reasons;
    Nuclear stations are even slower to adjust to varying loads than coal fired stations.
    Running then at full capacity brings the cost of their electricity to bearable levels i.e. about $94 per MWh (compare with coal at $40, wind at $140, solar $140 -250).

    Someone will now claim that France has 75% of its generating capacity from nuclear, and that those plants do load following. But that ignores that France is connected to Spain (thence Portugal), Italy, Switzerland, Belgium, the UK, and Germany (and through them to Austria, Czech Rep. Poland, Denmark (and through to Norway and Sweden).

    Should demand fall in France, they can shut down any gas fired plants first and switch excess electricity to their hydro stations for pumped storage. France has around 15% hydro capacity or double our percentage). They also have access to the Andorran, Spanish, Swiss, German, Austrian, Swedish and Norwegian hydro schemes.
    The switch is simple, they reduce the cost of their electricity so the rest of Europe starts using it by slowing their own production (and increasing usage into pumped storage). While this is going on, the french nuclear stations can go about slowing their production (if necessary).

    The same interconnections allow countries in Europe to manage the variable supply by wind farms, so long as not too many countries join in. Australia isn’t interconnected.


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    I know all the comments are offline for the moment and will be reappearing soon, but have a look at this in the interim.

    This is currently the best case scenario that is out there for what is very loosely termed as Base Load Solar. This is the method known as Concentrating Solar using the Power Tower method. Thousands of mirrors on heliostats that follow the path of the Sun focus that light on to a central point at the top of the tower. At that point is passed a salt compound that with the focused light then goes into a molten state. This molten salt is then used to boil water to steam which then drives a conventional turbine generator complex.

    It can generate 19.9MW of Power, and in the Summer months can theoretically generate power on a 24/7 basis. However, when spread across the whole year it only manages 63% Capacity Factor, so in the Winter months, you may only be looking at between 8 to 12 hours of power a day, so averaging it out over a year, that equates to around that 63% CF, which is around 15 hours a day, which, technically does not qualify as a Base Load provider.

    Now, I’ve been told by people who are fans of this form of solar power that this is not much worse than coal fired power, so in their minds anyway, this then is the equal of large scale coal fired power, which is patently incorrect.

    Let’s look then at Bayswater and do a comparison. Pretend for a minute that Bayswater’s CF is as low as that 63%. It’s actually closer to 75 and as high as 80% for some years, but for the sake of the exercise, let’s say it’s that 63%

    So now, comparing Bayswater’s 2640 MW, with this CS Plant, of 19.9MW, we will need 132 of these solar plants.

    That’s 132 of them.

    If they have admin problems trying to get one of them off the ground, imagine the admin etc for 132 of them.

    This plant comes in at $450 Million, so 132 of them now comes in at a total cost of almost $60 BILLION.

    $60 BILLION.

    Pretend for a minute that money is no object.

    The plant covers an area of 185 Hectares, so 132 of them now covers an area of 24,420 Hectares or in the old terminology, 100 square miles.

    Now think how long it will take to construct those 132 plants.

    Think of the infrastructure needed for the construction.

    Think of the infrastructure to get that power from wherever all these plants are to the grids where people can actually consume this power.

    Think then of the difficulty of arranging the finance for 132 of them if they’re having trouble with financing for just the one Solar Dawn plant in Chinchilla.

    Where does that money come from?

    How much money will the taxpayer be giving to foot the bill when Solar Dawn is half financed by the Feds and Qld State Governments.

    That’s $60 Billion in financing, just for the plants alone.

    How long will it take before all 132 are on line delivering power.

    They have a life span of barely 25 years at the absolute theoretical best case scenario, so as soon as they are finished if they can even accomplish that in those 25 years, then they’ll have to keep constructing more of them.

    And all of this to replace just the ONE large scale coal fired power plant.

    These people actually are just dreaming.

    This will NEVER be done. NEVER.

    And to top it all of, it doesn’t even count as a Base Load provider.

    These people are absolute stark staring crazy.

    And this is just to replace ONE large scale coal fired power plant ONE.

    Link to Gemasolar article.



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    Hi everyone, 100,000 comments have gone awol, 145 from this thread. We are working on getting them back. Hopefully by next week, it will all be fixed. – Jo


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    to TonyfromOz #5

    Thanks for that great description.

    You also need to subtract all of the “hotel” loads from the generated output. When the people pushing these “Green” monsters describe them they ALWAYS use “Name Plate” ratings. they never use typical real world output and never factor in the power used at the facility. Power is needed to pump the liquid salt, water (for steam) motors on the mirrors, lights in the operations/control facilities. Typically this is about 15 % of the delivered power. Every facility I have seen uses separate meters for the output, which they brag about how much they are providing and another set of meters for the house load supplies, which are impossible to find/determine unless you are one of the design engineers. I worked at one facility where they actually bought power from a different utility than the owner/builder.


  • #

    Link from the California ISO;

    http://www.caiso.com/outlook/SystemStatus.html#Todays Outlook

    It is a real-time update of the current supply and demand for California including ‘Renewables’.


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    We are still working on getting all the comments back. For those who want to read the originals, there is a copy of the google cache page here. 145 comments.


  • #

    Hey Tony, will could always go to ‘Poo Power’……..

    “$45,000 grant to Poo Power!

    Poo Power! is one of 63 successful recipients from Inspiring Australia’s ‘Unlocking Australia’s Potential’ program. The $45,000 grant has been awarded to the Yarra Energy Foundation to turn dog poo from parks in the City of Yarra into renewable energy.”


    They even have their own web page: http://www.poopower.com.au/index.html