06-07-2019, 01:15 AM

Hello Antti,

Could you explain me why there is no partial load efficiency loss for alkELSRMOBDECEN in the file attached? I am a bit confused now about your earlier explanation. My earlier model, when we discussed in the beginning was in different units. Now all are in PJ.

Earlier you told me partial loads are measured in proportional to the maximum load of each season. Since I do not have a constant demand profile. I calculated my load in every season. I have 480 time slices with 20 seasons as you could see in the attached model. For example, I checked my season 1, time slice S01Q02, the commodity fraction is 0. Then if the partial load is measured in proportion to the maximum load, my process should not work at all in this time slice, right? But still my process is working with full load efficiency. Why it is so?

Now if the partial load is measured according to the logic as explained below, still there are instances of low partial loads.

According to my understanding, I checked the partial loads in this file. I saw the capacity of my process alkELSRMOBDECEN which is 42.05 PJ/a. Now my load as I understand would be hydrogen demand. In this case alkELSRMOBDECEN (however, in the results one more process alkELSRMOBCEN_new is also serving this demand) is serving the demand DEMCARMOBDECEN and HYGNTOTRUCKMOB which the demand values are 19305 and 750 millionVkm. So combining two the demand would be 20055 millionVkm in 2050. This will be translated to 16.39+6.73 PJ(considering my demand technologies truck and car efficiencies of 1177.77 and 111) = 23.12 PJ annual demand. And the load profile is not a constant one. So to check the partial load, I calculated my load in each time slice by multiplying the annual demand with commodity fraction. And then I divided this by the value which I got multiplying year fraction and 8760. This means I got the load in each hour. I divided this load every hour with my capacity 42.05/8760 Pj/hr. In this case I am getting values like 0.1 and 1.2 etc. When I get 0.1, then the process should not work at all, right?

Now my confusion is how partial loads are measured. which of the above the logics are used to calculate partial load. And why there is no partial load efficiency losses in my results. Let's take the year 2050 for example.

NB:- I have further simplified my storage processess and the model is at least solving now. I have also decided not to consider pipeline as storage by making some cost reductions for my seasonal storage. Now I have two seasonal storages in the model. Still it's taking more than 1 hour to solve. One surprising thing is thus just by changing my demand values (ELCDEM) by a few numbers the model solving time changed from 31 minutes to 1 hour and 21 minutes. If you have some time, could you see why still after lot of simplications, the model is taking time?

Regards

Abi Afthab

Could you explain me why there is no partial load efficiency loss for alkELSRMOBDECEN in the file attached? I am a bit confused now about your earlier explanation. My earlier model, when we discussed in the beginning was in different units. Now all are in PJ.

Earlier you told me partial loads are measured in proportional to the maximum load of each season. Since I do not have a constant demand profile. I calculated my load in every season. I have 480 time slices with 20 seasons as you could see in the attached model. For example, I checked my season 1, time slice S01Q02, the commodity fraction is 0. Then if the partial load is measured in proportion to the maximum load, my process should not work at all in this time slice, right? But still my process is working with full load efficiency. Why it is so?

Now if the partial load is measured according to the logic as explained below, still there are instances of low partial loads.

According to my understanding, I checked the partial loads in this file. I saw the capacity of my process alkELSRMOBDECEN which is 42.05 PJ/a. Now my load as I understand would be hydrogen demand. In this case alkELSRMOBDECEN (however, in the results one more process alkELSRMOBCEN_new is also serving this demand) is serving the demand DEMCARMOBDECEN and HYGNTOTRUCKMOB which the demand values are 19305 and 750 millionVkm. So combining two the demand would be 20055 millionVkm in 2050. This will be translated to 16.39+6.73 PJ(considering my demand technologies truck and car efficiencies of 1177.77 and 111) = 23.12 PJ annual demand. And the load profile is not a constant one. So to check the partial load, I calculated my load in each time slice by multiplying the annual demand with commodity fraction. And then I divided this by the value which I got multiplying year fraction and 8760. This means I got the load in each hour. I divided this load every hour with my capacity 42.05/8760 Pj/hr. In this case I am getting values like 0.1 and 1.2 etc. When I get 0.1, then the process should not work at all, right?

Now my confusion is how partial loads are measured. which of the above the logics are used to calculate partial load. And why there is no partial load efficiency losses in my results. Let's take the year 2050 for example.

NB:- I have further simplified my storage processess and the model is at least solving now. I have also decided not to consider pipeline as storage by making some cost reductions for my seasonal storage. Now I have two seasonal storages in the model. Still it's taking more than 1 hour to solve. One surprising thing is thus just by changing my demand values (ELCDEM) by a few numbers the model solving time changed from 31 minutes to 1 hour and 21 minutes. If you have some time, could you see why still after lot of simplications, the model is taking time?

Regards

Abi Afthab