BETÜL ÖZER 7/11/2011

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As I'm modelling electricity generation and related CO2 emissions, I recognised that the efficiency value I have entered directly to the "process efficiency tab" is not same as I calculated from output and input energy. I get from results view "transmission outputs" and "transmission inputs" the ratio should be the efficiency value as I have entered, shldn't? Would you pls kindly inform me about it? This is the last main issue for the CO2 emissions. You can check the results and values entered from any of the scenarios eg.REF1.

Note. I'm using the older version 2008.0.0.96.
Rgds,

Betül

Charlie Heaps 7/11/2011
 

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Hi Betül,

Yes that ratio should give you the efficiency. Could you send me your data set so I can investigate? Have you tested to see if you get the same result in v2011?

Thanks,

Charlie

BETÜL ÖZER 7/19/2011
 

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Dear Charlie and Tori,
Did you have time to check my file? It is important for me to learn what is wrong with the data?Hope older version:096, is not the problem.

Hope to get reply soon.

Rgds,

Betül

Tory Clark 7/19/2011
 

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Hi Betül,

I was able to take a look at your file today, and I think I have identified the issue with your calculations.

You are correct that the "process efficiency" variable will define the energy content of the output fuels as compared to the feedstock fuels. This does not include any additional auxiliary fuel use that you identify for each process. It looks like you have identified auxiliary fuel use for most processes. This fuel use will be included in the "inputs" results chart because it includes any inputs (feedstock + auxiliary fuels).

This means that with auxiliary fuel use your efficiency will seem less than what you entered in process efficiency if you look at the transformation inputs/transformation outputs.

You can check this by making auxiliary fuel use zero for one fuel and check the results that way.

Best,

Tory

BETÜL ÖZER 9/26/2011
 

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Hi Tory,
Thank you for your reply. But I have still a question. I entered auxiliary fuels for all my process, because all have internal consumption as electricity. My question is:
- I entered process efficiency, LEAP calculates output value of the fuel and input value. But the process efficiency is not the same as I entered LEAP. I think this is related with the auxiliary fuel (which is internal consumption of the process). But how LEAP calculates input value. The process efficiency I entered is :GWh/(GWh energy produced)
I need the algorithm for calculation of the auxiliary fuel use. I'll send again my file. LEAP have output value for a fuel, process efficiency and auxiliary use. As you mentioned process efficiency is lower than I entered because of auxiliary use. But how is the calculation?
Wld you pls tell me the by an example of a fuel.
I'm using 2008,00,96 version
Thanks in advance and regards.

Betül

Tory Clark 10/12/2011
 

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Hi Betül,

Just to clarify, the way you have electricity module variables set up in LEAP is to dispatch to full capacity and to "Meet auxiliary energy needs from outputs of same process where possible" as indicated by the checked box in the Basic Parameters: Calculations tab.

This means that LEAP's calculations get a bit more complicated than usual. You are telling LEAP that the process itself needs to produce more energy to meet both its generating requirements and its own-use requirements.

To understand what is going on you have to understand that your model is not running to demands but is instead running as much as is possible (i.e. to full capacity). With this in mind, when viewing results, Outputs should be equal to the Capacity*Availability*8760 - Auxiliary electricity requirements. This chart doesn't always seem to be calculating correctly because LEAP is not currently set up to derate current capacity with auxiliary requirements (another option within basic parameters).

My recommendation is when representing auxiliary electricity requirements in an electricity module to use only the efficiency variable rather than the auxiliary fuels branches. Since efficiency is representing the ratio of outputs and inputs for a given module, this should work.

You could also uncheck the box in basic parameters to meet auxiliary requirements from the same process, which will simplify the calculation.

I hope this helps!

Tory