constraint on capacity growth rate

[Samaneh]

Hello,

I want to define upper bound constraint on the growth rate of the vehicles capacity in my model. Actually everything works right except that the annual growth rate of the capacity doesn't work quite right.

Growth approach

~UC_Sets: R_E: AllRegions

~UC_Sets: T_SUC:

                                                 ~UC_T

UC_N Pset_PN Pset_CI Pset_CO UC_ATTR~LHS UC_ATTR~RHS   LimType       UC_CAP~LHS

UC_Car TLDSL TRNDSL TMDLDV CAP                  CAP,GROWTH      UP                  1          

UC_CAP~RHS  UC_RHSRT UC_RHSRT~0

 1.2                      12                     5

The problem is that I have maximum annual growth rate of 20% but when I check the capacity growth of TLDSL process, it starts from 12 billion miles that I specify in the constraint, but in the first five years it goes up to 42 billion mile which means 28% growth rate per year instead of 20%!

Thanks for your help,

Samaneh

[Samaneh]

Hello,

I think I figured out how the capacity is calculated. Model includes the constant capacity (12 billion miles) in the maximum capacity calculation of each time period. For example, for the next 5 years, the capacity would be 12+ 12*(1.2^5)=42.

Samaneh

[Antti-L]

Yes, the constraint you modeled can be written as:

CAP(TLDSL,T) ≤ CAP(TLDSL,T-1)*1.2^(M(T)-M(T-1)) + 12

where M(T) is the milestone year of period T. So, if you don't want the constant 12 to be added to the maximum growth, just set it to zero for some or all periods.