Topic: Problem with Hydro importSubscribe | Previous | Next
Suman Shrestha 8/24/2015
932 Views Hi,
I am developing energy balance table using LEAP. Electricity generation is being done by Hydro. I've kept efficiency of process to be 80%. But in output, there is import of Hydro in the energy balance table. I checked if I have made mistake, but didn't find one. I have entered data in "yield" only which is what I get in Production in energy table. I don't know where the data for import came in energy balance.
Suman Shrestha
Taylor Binnington 8/24/2015
931 Views Suman,
I don't see electricity being produced anywhere, nor are there any requirements for it on the demand side - it looks like your screenshot does not show that column. Can you scroll to the left in order to show other fuels in your balance?
Without seeing the electricity flows in your table, I can only speculate that electricity demand is simply higher than your hydro yield can support. 17,280 TJ is being produced domestically, but the remainder of the hydro requirements must be imported in order to generate sufficient electricity.
Taylor
Suman Shrestha 8/24/2015
930 Views Dear Mr. Binnington,
Sorry, my bad. I am including the screenshot that shows electricity column as well. Hydro is utilised by electricity generation and by microhydro as well. Very small amount of electricity is generated by diesel plant. There should be no import in Hydro. However, energy balance shows the import. I am wondering why. Please help.
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Taylor Binnington 8/24/2015
929 Views Hi,
Again, if your hydro yield (this is the domestic, annual production potential for hydro) is not sufficient, then hydro will be imported. Alternatively, you may choose to leave any remaining requirements as 'unmet', instead of imported, by right-clicking and viewing the properties of the hydro fuel found under Resources\Primary.
What is the value you have entered into the Yield variable for hydro, in the resources branch?
Taylor
Suman Shrestha 8/24/2015
928 Views Hi,
I've entered 17280 TJ in hydro's yield in resource branch. And nothing in import. When I do as u said "leave any remaining requirements as 'unmet'", it works but electricity generation still uses more than that in yield. I've data of electricity generation including microhydro (740 TJ) and hydropower (13084 TJ). So, I back calculated hydro assuming 80% efficiency i.e. (13084+740)/80%=17280 TJ). In the process efficiency of electricity generation, I've kept efficiency to be 80%, but generated electricity in energy balance is more than 13084 TJ (and 5TJ by thermal process. I am wondering why.
Taylor Binnington 8/24/2015
927 Views Hi Suman,
I'm not sure how you arrived at 13084 TJ. Your energy balance shows that 13467 TJ of electricity is demanded, so as long as there is sufficient generating capacity available, your electricity generation module will try to meet these electricity requirements.
Leaving the Resource Imports variable blank does not mean there will be zero imports. At the end of you calculation in each year, LEAP decides if additional imports are required as part of your total primary energy supply (or leaves these requirements unmet, as you've observed - but this does not change how your electricity generation module operates to produce electricity).
Hope this helps,
Taylor
Suman Shrestha 8/24/2015
920 Views I agree that my demand is 13467 TJ. I have to include transmission loss also. So the demand will be much higher. That's why there is import in Electricity, as I have entered manually for electricity (4932 TJ). It seems that this import has not been considered and LEAP has calculated as per demand requirement. I dont know why.
I also would like to know how to incorporate transmission loss of electricity.
Thank you.
Suman
Taylor Binnington 8/26/2015
913 Views Hi Suman,
I'm afraid I don't understand your last reply, and I'm not sure what you mean when you say that you have manually entered imports for electricity. Let us also defer the discussion of transmission and distribution losses, since I think it just complicates the discussion of imports for the moment. I would suggest that you review section 1.4.1 of our training materials, for an introduction to one technique to handle losses in LEAP:
http://www.energycommunity.org/documents/LEAPTrainingExerciseEnglish2014.pdf
Based on the information you've given in this thread, what I see is that 17735.4 TJ of hydro is consumed in the transformation part of your model. This is greater than the yield you have specified under Resources, therefore hydro is imported to make up the difference.
If this still conflicts with your expectations, please tell me exactly which values you would expect to see in your energy balance table, and attach a copy of your model (as a *.leap file) to this thread.
Best,
Taylor
Suman Shrestha 8/26/2015
840 Views Dear Taylor,
Thank you for your replies. I think I've not been able to relay my problem to you. That's why I am including Energy balance table in excel format which I intend to make in LEAP. Also I am including leap file. I've got to make energy balance in leap as it is in excel file. So, you may see that my problem lies with Hydro and Electricity generation.
I appreciate your help.
Thank you
With Best regards
Suman
DSM Intervention.leap [6]
,
Energy Balance.xlsx [5]
Taylor Binnington 9/15/2015
837 Views Hi Suman - sorry for the late reply, I've just gotten back from holidays.
The source of disagreement between your Excel energy balance and your LEAP model comes from where you have specified Imports and Exports in the model. When you write values into the Resource Imports and Resource Exports variables (found in the Resources branches at the bottom of the tree), these imports/exports are added at the end of the annual calculation once all of the transformation calculations have resolved. In other words, your Electricity Generation module will use its available processes to meet all of its requirements, and then once it is finished, additional electricity is imported because of what you've written into the Resource Imports variable. These imports are then wasted (this shows up as a negative unmet requirement for electricity in LEAP's Energy Balance view), since demand has already been satisfied.
Instead, you should specify imports and exports using the Import Target and Export Target variables which are found for each of the electricity generation module output fuels. This will allow those imports/exports to reduce/increase the requirements for the module, causing your power plants to run less/more. When I make this change in your model, I get much better agreement with your spreadsheet energy balance.
Hope this helps,
Taylor