Post by eclipse on Jun 30, 2012 11:18:54 GMT 9.5
Hi all,
I'm trying to explain capacity factor in a very basic manner to a bunch of lay people in a Facebook group... one lay person to another. So I'm looking for very basic 'ratio' summaries, and noticed this one.
bravenewclimate.com/2012/03/21/trainer-critique-edm/
But I wanted to break it down even further than this, in layman's terms, and compare it to today's coal based grid. Roughly speaking this paragraph basically says a renewable powered grid would be so unreliable that it would need just under 3 times the capacity to produce today's electricity. But people like Mark Diesendorf reply that today's grid is already so backed up it can handle when a coal-fired power plant suddenly, unexpectedly, shuts down. Then Mark sneakily presents a wind farm as MORE RELIABLE than coal because instead of a gentle drop off in wind power which are far smaller power plants and is usually predictable days in advance with modern weather modelling, the grid has to cope with a whole gigawatt of juice suddenly dropping off!
So my question is: if 'unreliables' require a grid that is backed up by building nearly 3 times the capacity required, how does the current coal-based grid compare? I'm a bit embarrassed to admit that I can't quote exactly how many coal plants Australia has, and how many of them are sitting there acting as emergency backup for when another plant might suddenly go down, or more routinely go down for a booked in servicing. With a baseload power grid I'm imagining that we might have a coal-plant that acts as backup for maybe 3 or 4 other power plants? Is that right? Or is it far more?
Cheers, and thanks in advance for breaking it down to someone who went into the humanities.
I'm trying to explain capacity factor in a very basic manner to a bunch of lay people in a Facebook group... one lay person to another. So I'm looking for very basic 'ratio' summaries, and noticed this one.
///The task is to supply 31 GW. The plots given show that at one point in time wind is contributing a maximum of 13.5 GW, but at other times its contribution is close to zero, meaning that other sources are backing up for it. The corresponding peak inputs from the other sources are, PV 9 GW, solar thermal 27, hydro 5 GW and gas from biomass 24 GW. Thus the total amount of plant required would be 75.5 GW of peak capacity… to supply an average 31 GW. (in his response to Peter Lang, Mark Diesendorf says their total requirement is 84.9 GW.) That’s the magnitude of the redundancy problem and this is the major limiting factor for renewables; the need for a lot of back up plant, which will sit idle much of the time.///
bravenewclimate.com/2012/03/21/trainer-critique-edm/
But I wanted to break it down even further than this, in layman's terms, and compare it to today's coal based grid. Roughly speaking this paragraph basically says a renewable powered grid would be so unreliable that it would need just under 3 times the capacity to produce today's electricity. But people like Mark Diesendorf reply that today's grid is already so backed up it can handle when a coal-fired power plant suddenly, unexpectedly, shuts down. Then Mark sneakily presents a wind farm as MORE RELIABLE than coal because instead of a gentle drop off in wind power which are far smaller power plants and is usually predictable days in advance with modern weather modelling, the grid has to cope with a whole gigawatt of juice suddenly dropping off!
So my question is: if 'unreliables' require a grid that is backed up by building nearly 3 times the capacity required, how does the current coal-based grid compare? I'm a bit embarrassed to admit that I can't quote exactly how many coal plants Australia has, and how many of them are sitting there acting as emergency backup for when another plant might suddenly go down, or more routinely go down for a booked in servicing. With a baseload power grid I'm imagining that we might have a coal-plant that acts as backup for maybe 3 or 4 other power plants? Is that right? Or is it far more?
Cheers, and thanks in advance for breaking it down to someone who went into the humanities.