CHP Scoping Model v0.1

The most recent version of this model can be found here.

My motivation for producing this model is to give engineers something to dig their teeth into.

My first few months as an energy engineering graduate were spent pulling apart the standard CHP model used by my company.  A few years later I was training other technical teams how to use my own model.

I learnt a huge amount through deconstructing other peoples models and iterating through versions of my own.

So this model is mostly about education. I would love it to be used in a professional setting – but we may need a couple of releases to iron out the bugs!

In this post I present the beta version of a CHP feasibility model.  The model takes as inputs (all on a half hourly basis):

  • High grade heat demand (Model : Column F).
  • Low grade heat demand (Model : Column G).
  • Electricity demand (Model : Column H).
  • Gas, import & export electricity price (Model : Column BF-BH).

Features of the model:

  • CHP is modeled as a linear function of load. Load can be varied from 50-100 %.
  • Can model either gas turbines or gas engines. No ability to model supplementary firing.  Engine library needs work.
  • The CHP operating profile can be optimized using a parametric optimization written in VBA.
    • Iteratively increases engine load from 50% – 100% (single HH period),
    • Keeps value that increased annual saving the most (the optimum),
    • Moves to next HH period,
    • Optimization can be started using button on (Model : Column BV). I reccomend watching it run to try understand it.  The VBA routine is called parametric.
  • Availability is modeled using a randomly generated column of binary variables (Model : Column C).
You can download the latest version of the CHP scoping model here.

Thanks for reading!

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