I am trying to model the utilization of two different biofuels in the same improved cookstove. I would like to use a certain Biofuel A when it is available and use Biofuel B when there is no Biofuel A available. Can I dispatch the processes according to a order of priority? Is it possible to use two different fuels in the same technology? Or do I need to dispatch the biofuel-supply processes in the Transformation module?

I continue to use the 2017.11 version.

Best regards

Ricardo Carvalho

I can see a couple of different ways to model this in LEAP, using either supply-side modules or on the demand side. But first, can you tell me how you are including data in LEAP about the availability of biofuels A and B? Are you trying to include this in the Resources branches?

To be clear, resource adequacy (i.e. through yields or domestic reserves) entered within the Resources branches do not inherently affect LEAP's supply or demand calculations because resource requirements are resolved after all of the demand and transformation calculations have finished. This means that you will need to use a LEAP expression to insert some type of function which relates the Activity Level of a branch (if the resource constraint is to be modeled on the demand side), or often the capacity of a transformation process (if the resource constraint is to be modeled on the supply side) to the annual yield or the reserve of the fuel being consumed.

Hope this is useful,

Tayor

Thanks for your reply. Yes, I have trying to include this on the resource branch. Perhaps I could also use the new Land-use tool. The idea would be to prioritize the use of biomass residues, instead of natural forest. Then, one could see the effect of a policy on the utilization of biomass residues in the form of pellets or briquettes could effect on the forest conservation?

Best regards

Ricardo Carvalho

Indeed, the latest version of LEAP incorporates some new features to help you identify which types of biomass (and which land types) are being harvested, and to quantify the remaining stocks in each year. However, these calculations are still performed after the basic demand/supply energy accounting is done in LEAP, and so the availability of different biomass types will still not automatically be reflected in LEAP's accounting of total requirements.

One strategy that can be used here is to build a transformation module which produces a generic "biomass" fuel with two or more processes, each consuming a different type of biomass - in your case, biomass residues and natural forest. You may then write an expression into the Exogenous Capacity for each of these processes - or at least for those processes which consume a finite resource - which refers to the annual yield of the resource*, so that one of the processes' capacity is constrained by the availability of its feedstock. If you dispatch these two or more processes by merit order, you can structure your module to use the biomass residue process first, only dispatching the "natural forest" process once the capacity of the biomass residue process is exhausted.

Hope this helps,

Taylor

*Note that using a LEAP expressions to refer to the calculated yield of a land-based resource which uses the newly-added LEAP features, is still under development.

Thanks for your suggestions. If I want to design it through the transformation unit, shall I indicate in the model the resources available in the Resource branch? I cannot see the Yield for the biomass resources in the new version of LEAP. I could indicate it in the past version, but I cannot do that in this one. Is this some kind of bug as suggested by another colleague here before?

Or shall I indicate the availability of biomass resources when I design the biomass processes in the transformation branch. Shall I do that in the exogenous capacity by introducing a LEAP expression that relates the feedstock consumed in energy units by converting the mass of feedstock to energy units, for instance by multiplying the mass of wood by the lower heat value of the wood?

Ricardo

You may do either of the two options you suggested. However, you're quite right that the Yield variable is not shown right now for biomass resources, so you will temporarily need to include all of your biomass availability using the variables available to you in a transformation module (i.e. Exogenous Capacity, Maximum Availability).

I'll be in touch with you again via this thread once we resolve the appearance of the Yield variable.

Best,

Taylor

The appearance of the "Yield" variable in LEAP should be resolved in recent versions of LEAP.

Taylor