13-10-2010, 07:47 PM
Nothing seems too unusual. Hmm. Do you think it could have something to do with my biomass supply curves? I will explain. I have supply curves for 12 different types of biomass. Each curve has somewhere between 5 and 20 cost steps. If you were to look at the curves, you would see that costs gradually increase, then the last few PJ of biomass (which makes up less than 1% of the total supply) increases dramatically (i.e., the typical straight vertical cost increase of a supply curve for the very last resources). The model doesn't like to use these high-cost biomass supplies at these final steps on the supply curves, but perhaps this is leading to the CO2 price spikes.
Just to give you a feel for the numbers, most of my biomass is in the range of $1 to $12 per GJ. Then, the last few steps shoot the cost up to $435/GJ, and even up to $782/GJ. Obviously, such high biomass costs would lead to extremely high CO2 prices, if this biomass were consumed. But in fact, this high-cost biomass is not being consumed. Thus, I wouldn't expect it to enter into the model's calculation of the marginal cost of CO2.
I should mention that I have had some other indications that my biomass resources and biomass conversion technologies are responsible for the high CO2 prices, so I'm kind of expecting this to be the source of the problem. However, I just can't put my finger on exactly what the problem is.
Just to give you a feel for the numbers, most of my biomass is in the range of $1 to $12 per GJ. Then, the last few steps shoot the cost up to $435/GJ, and even up to $782/GJ. Obviously, such high biomass costs would lead to extremely high CO2 prices, if this biomass were consumed. But in fact, this high-cost biomass is not being consumed. Thus, I wouldn't expect it to enter into the model's calculation of the marginal cost of CO2.
I should mention that I have had some other indications that my biomass resources and biomass conversion technologies are responsible for the high CO2 prices, so I'm kind of expecting this to be the source of the problem. However, I just can't put my finger on exactly what the problem is.