The value of monthly peak demand is not consistent in two different energy simulation report.

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Hi,

I am working on the energy model using eQuest 3.65 and the project is based
in Down town Washington DC. I have used the weather file nearest to the
project location i.e., Maryland.

I am having the situation where I don't understand that, after the
simulation done the peak demand (kW) value of particular month in the
energy simulation report ES-S is not matching with the value of same in the
another energy simulation report PS-B from the same model.

Please advise on where I could be wrong because of that I am getting the
different peak demand (kW) value of particular month in two different
reports (ES-S & PS-B).

Kindly find the attached pics highlighting the different peak demand of
same month in two different reports (ES-S & PS-B).

Thank you for your time and hoping to hear immediate response to this
matter.

Regrads,
Nitin J Harjai

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Hi Nitin,

Quick answer: ES-E is expected to reflect demand measurements which account for the DEMAND-INTERVAL specified (or defaulted: 15 minutes in the case of electrical meters & 1 hr in the case of all others). These will generally be higher than demands reported elsewhere in the simulation outputs.

Teaching a man to fish, you could figure this out by:

1. Reviewing the annotations provided for both detailed simulation reports under Help --> Tutorials and Reference --> Detailed Simulation Reports Summary (pdf)

[cid:image003.png at 01D4D344.8A869660]

1. Reviewing the associated doe2 reference manual entries for the rate DEMAND-INTERVAL and related inputs, by right clicking them

[cid:image005.png at 01D4D345.82055A20]

In case this isn?t intuitive?

1. You can read a fair analogy regarding how demand intervals work in the real world here: https://www.northwesternenergy.com/docs/default-source/documents/E-Programs/E-demandcharges.pdf
2. By way of further explanation/example, you can make ES-E report demand each month to match what?s shown in the other SIM reports by specifying a 60 minute DEMAND-INTERVAL for your custom rate (which appears to have two uniform blocks), as illustrated here:
[cid:image004.png at 01D4D344.8A869660]

You can leverage that input more purposefully to have ES-E reflect daily peaks, or sub-hourly measurements of a different resolution.

Finally, and because demand outputs from doe2/eQuest is fairly stated a minefield of potential misinterpretation, I?ve copied a ?guide? I put together some time ago for further reading (to satiate any further interest that may be remaining ?). It breaks down a series of additional means by which monthly demand can be read from different reports/outputs, to different ends.

Some might also be wondering (as I did) what exactly eQuest is calculating at a sub-hourly resolution to make these inputs meaningful in the first place. It turns out a helpful fellow (me) wrote up his findings on that matter and I?ve copied that info below as well.

Sorry Nitin? this email just became really big =/? Hope some of this is helpful however!

~Nick

[cid:image001.png at 01D4D342.4D1AEEE0]
Nick Caton, P.E., BEMP
Senior Energy Engineer
Regional Energy Engineering Manager
Energy and Sustainability Services
Schneider Electric

D 913.564.6361
M 785.410.3317
F 913.564.6380
E nicholas.caton at schneider-electric.com

15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219
United States

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