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Duffman · 10-09-2008, 10:11 PM

The numbers I have seen are duty cycles of 30 and 20% respectively for wind and solar. The only thing reliable that you can say for either one of them is that reliably you can predict there will be no solar power during the night. There will be times when neither is worth a damn and their duty cycles suggest that it will be more times than you think. To get it to work you need Wave and Geothermal to emulate the performance of our current thermal supply. Is there enough of both to replace our current thermal supply, because as James points out, they are small units and our big thermal plants are about 1000MW. This also speaks nothing to whether or not a particular site is a good location for either technology. Same for Hydro, really the hydro is there or it is not, Germany with less than 5% hydro was not endowed with those resources plain and simple.

We will always need peaking plants, right now they are Hydro and Gas, if you have no hydro, then you are pretty dependent on gas. Can we make enough BioGas? We know right now we can’t make enough ethanol to meet our needs, why would we think we can cover additional bases as well.

This is not a problem of taking 4 or so sources of electricity, summing up their W*hours and saying that it meets the avg need over a years worth of time. Supply must equal demand at every single second of the year or the system doesn’t work properly.

To put it in an analogy, right now we have a toddler sized person falling from one story when renewable supply doesn’t meet expectations and a 200 lb man (conventional supply) underneath him to catch him and break his fall. But it won’t work the other way around, the toddler is not capable of catching the man should he be the one falling from one storey up. You can’t make unpredictable renewables the size of the man and reliable sources the size of the toddler.

And all this talk of storage and mass transport of electricity is just grasping at straws to make an unworkable system workable, but nobody will go for it when they see what it means in the end.

10-09-2008, 10:11 PM	#48 (permalink)
Duffman Master EcoModder Join Date: Mar 2008 Location: Edmonton, AB, Canada Posts: 531 Thanks: 11 Thanked 12 Times in 11 Posts	The numbers I have seen are duty cycles of 30 and 20% respectively for wind and solar. The only thing reliable that you can say for either one of them is that reliably you can predict there will be no solar power during the night. There will be times when neither is worth a damn and their duty cycles suggest that it will be more times than you think. To get it to work you need Wave and Geothermal to emulate the performance of our current thermal supply. Is there enough of both to replace our current thermal supply, because as James points out, they are small units and our big thermal plants are about 1000MW. This also speaks nothing to whether or not a particular site is a good location for either technology. Same for Hydro, really the hydro is there or it is not, Germany with less than 5% hydro was not endowed with those resources plain and simple. We will always need peaking plants, right now they are Hydro and Gas, if you have no hydro, then you are pretty dependent on gas. Can we make enough BioGas? We know right now we can’t make enough ethanol to meet our needs, why would we think we can cover additional bases as well. This is not a problem of taking 4 or so sources of electricity, summing up their W*hours and saying that it meets the avg need over a years worth of time. Supply must equal demand at every single second of the year or the system doesn’t work properly. To put it in an analogy, right now we have a toddler sized person falling from one story when renewable supply doesn’t meet expectations and a 200 lb man (conventional supply) underneath him to catch him and break his fall. But it won’t work the other way around, the toddler is not capable of catching the man should he be the one falling from one storey up. You can’t make unpredictable renewables the size of the man and reliable sources the size of the toddler. And all this talk of storage and mass transport of electricity is just grasping at straws to make an unworkable system workable, but nobody will go for it when they see what it means in the end.