Topic: Plants not dispatching correctlySubscribe | Previous | Next
Saadia Qayyum 3/24/2015
1240 Views Dear Taylor and Charlie,
I am working on the energy reference system of Pakistan and have modelled all the existing and planned plants in LEAP. I am facing the following problem:
My base year is 2014 and the first calculation year is 2015. When I run the model the demand is unmet as hydro, RFO and gas plants all dispatch less than available capacity. I am attaching LEAP backup file. I checked everything but can�€™t figure out what is going wrong.
Could you please check where the error is?
Saadia
Pakistan Generation with GOP Planned Plants-S.leap [8]
Taylor Binnington 3/24/2015
1239 Views Hi Saadia,
A few things to point out:
a) During your Current Accounts period, your plants are dispatching more than the module requirements. This is because LEAP obeys the 'Historical Production' variable:
http://www.energycommunity.org/WebHelpPro/Transformation/Base_Year_Output.htm
...during your base year of 2013 and 2014. But starting in the First Simulation Year (which is 2015 for most of your plants):
http://www.energycommunity.org/WebHelpPro/Transformation/First_Simulation_Year.htm
...LEAP takes over control of process dispatch.
b) Once LEAP begins process dispatch calculations starting in 2015 (or in 2016 or 2017 for some plants), it is limited to the amount of available capacity. I can see that you've written values into the Historical Production of some of your plants that cause them to utilize *more* than their available capacity in Current Accounts - but as soon as LEAP takes over dispatch, the generation from these plants will drop substantially.
Note that when a user enters a Historical Production value that causes a plant to run more than it's available capacity, LEAP will give a diagnostic message in the 'Diagnostics' tab of the Results view.
In helping you track down problems with dispatch, the Transformation: Requirements result can be very useful to determine what the module requirements are.
Hope this helps,
Taylor
Saadia Qayyum 3/24/2015
1218 Views Thank you Taylor. I have two follow up questions:
1) When I try to set my first scenario year as 2013 (a year before base year) to have all years dispatched, it doesnt work for me. It still gives me the historical generation as that I have entered.
2) Why does the generation fall so much in 2015 and 2016? In the following years it is increasing linearly with gradual increments but in 2015 and 2016. the generation is much lower that in rest of the years. In the attached model, I have allowed the model to add new plants starting in the first simulation year. Even then it doesnt generate more than 64,000 GWh in 2015.W Why is there such a large difference?
3) For all the years, electricity is being imported to meet the demand. However, I would like the model to be meeting all the demand through indigenous production of electricity with no power imports. How do I restrict the model from importing electricity?
I am attaching my new backup file which has both planned and new plants added.
Thank you
Saadia
Generation with new and planned plants.leap [5]
Taylor Binnington 3/27/2015
1213 Views Hi Saadia,
1) I'm afraid I can't reproduce this. Can you give me clear steps to follow, so that I can try to reproduce your problem? The historical production variable should only be used in years before the First Simulation Year, and this is what I'm observing in your model.
2) First - LEAP builds endogenous capacity to satisfy the reserve requirements regardless of the First Simulation Year. This variable is only used to control plant dispatch, not capacity expansion.
Since you have set the First Simulation Year to 2016 or 2017 for some of your largest power plants, yet the Historical Production for these plants is zero, you will find that not enough power is being generated to meet module requirements during 2015 - 2017. In 2014, it looks like you've entered enough Historical Production across of your plants that demand is met - in fact, some power is even exported in this year.
3) Endogenous Capacity is added so that the reserve margin is satisfied, which is calculated according to the equation here:
http://www.energycommunity.org/WebHelpPro/Results_Categories/Reserve_Margin.htm
Note that the reserve margin depends upon the Capacity * Capacity Credit, but does not depend upon the Maximum Availability of the process. Therefore depending on the relative magnitudes of your Capacity Credit and Maximum Availability variables (as well as the reserve margin that you specify), *it is possible to satisfy the reserve margin yet not have enough available capacity to meet the module requirements*. In this case, LEAP imports the remainder.
To fix this, I would suggest more carefully addressing your Capacity Credit variables for each plant - as a first approximation, you may choose to set them equal to the maximum Availability of the process.
Good luck,
Taylor