Jimmy Fransson 2/4/2016

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Hi!

I've done Exercise 1 & 2, in Excel, simulating the way LEAP works, whole demandside and the electricity generation side. I read mostly in your manuals to understand what LEAP does, however, in the manual for calculating how the dispatching is done on a load curve with merit order, I ran into a problem.

http://energycommunity.org/WebHelpPro/Transformation/Dispatching_Processes_on_a_Load_Curve.htm
The manual says that it creates vertical "strips" where the height is calculated by required peak power multiplied by the average load % of adjacent 2 points. Doing this and then dispatching base and peak powerplants gave me a slightly wrong output compared to LEAP. However, when I did NOT use the average load % of the adjacent 2 points and used the specified load %, it summed up to the correct output. (Also for each powerplant, that can be seen in the results "average power dispatched").

Does it say wrong in the manual or does it have something to do with how the load curve is specified? "stairs"-wise or straight lines, etc? In the training exercise it says that the 100%-point is implicit, but also need to be added explicitly.. Confusing with the picture as well..

To me it seems as if LEAP does not uses the average load % for calculating the supply-side? I.E the vertical "strips" in the graph in the manual I linked will only be on the inside of the line? Or does it have something to do with the 100%-not-seen load% and the minimum 10%? When I tried the averaging-method, I used 100% as first point, but not 10% as a minimum because then it's 1 more vertical strip (with 0 width)..

Thanks for any clarification!

Taylor Binnington 2/9/2016
 

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Hi Jimmy,

I agree with you there there is some room for confusion in the help manual. Let me try to clarify.

LEAP calculates dispatch requirements in each time slice by directly using the value specified in the Yearly Shape which corresponds to that time slice. So when entering data into your load curve, each value should be interpreted as the average value for that time slice - i.e. the height of the rectangle. No further averaging over adjacent points is necessary.

The result Transformation: Peak Power Requirements is by definition equal to 100% of the *instantaneous* peak load on the module. However, instantaneous peak load is calculated for a "hypothetical" time slice of zero width, so there are no electricity generation requirements associated with it. Instead, the instantaneous peak load is used only to calculate the module's reserve margin:

http://www.energycommunity.org/WebHelpPro/Results_Categories/Reserve_Margin.htm

When specifying Yearly Shapes for percentages of peak power requirements, you are free to specify a value that is less than 100% in the first time slice. This means only that the average power requirements across the whole first time slice are less than the instantaneous peak load for the system.

The value given in the "Minimum:" field for peak load curves has no affect on the module's dispatch.

If you cannot reproduce LEAP's results in Excel, are you certain that you've specified enough available capacity for requirements to be met in each time slice?

Hope this is clear,
Taylor

Jimmy Fransson 2/10/2016
 

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Hi Taylor!

Thanks for your answer. So if I understand correctly, the values one specifies in the manual for the exercise are the actual average values already.

I did manage to reproduce LEAP's results in Excel, matching 100%, with correct addition of endogenous capacity when needed and keeping a correct planned reserve margin, for each year and changing demand/values. It was just the question about the "averaging" for the dispatching really, as I didn't understand the manual compared to the results I got from LEAP and the ones I had in Excel.

I'd also like to mention that, in the yearly shapes: System Load Curve -window in LEAP, when holding your pointer above the "sort values", "slice names" and "stair lines", the hint says "Click and drag on a point to edit its value". Which has nothing to do with those 3 check-boxes. Maybe you've fixed it in an later version already though (I have 2015.0.10.0).

Thanks for your help!

Taylor Binnington 2/10/2016
 

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Hi Jimmy - you are correct, the values given in the manual are already the average values.

Thank you for pointing out the mouseover message. Though it hasn't been fixed, I wanted to let you know that we did release an updated version of LEAP yesterday (2015.0.16.0). You'll be able to download it here:

http://www.energycommunity.org/download

All the best,
Taylor