CHP template wishlist

[Villyes]

This is a wishlist for a perfect template that is understandable and can deal with several different inputs for the three operation modes.

[Villyes]

This is what the template could do plus what I would immediately need for ENABLE DHC/ Wien:

power_max: null
power_at_hmax:
power_min:
heat_max: null
heat_min:

power_ratio: 0.55
power_loss_ratio: 0.20
efficiency_condensing_max:
efficiency_backpressure_max:
mode: backpressure, full_field [pure condensing unnecessary imo, what do you think?]

availability:
availability_factor:

fuel: gas
fuel_co2_emission_factor: 0.2
fuel_in: null
power_out: null
heat_out: null
co2_out: null

[sstroemer]

Two quick questions to make sure I understand the parameters correctly:

1. Are the efficiency_***s "electrical" efficiencies at the given point (so kind of targeting power_out[t] / fuel_in[t])?
2. What's the relation between p_at_hmax and power_ratio? What happens if p_at_hmax != power_ratio * h_max?

[Villyes]

1. Are the `efficiency_***`s "electrical" efficiencies at the given point (so kind of targeting `power_out[t] / fuel_in[t]`)?

Correct. (Or was the "default" for backpressure a heat-based efficiency? Help from the others please! @nyashags @annalackner07)

2. What's the relation between `p_at_hmax` and `power_ratio`? What happens if `p_at_hmax != power_ratio * h_max`?

p_at_hmax is for the representation of the "pure" triangle. Project partner gave me this value in combination with p_max and h_max and I calculate the power_loss and power_loss_ratio from it.

The template should be able to deal with different inputs.
one option (min version): h_max, p_max, p_at_hmax (represents a triangle)
other option (min version): h_max, p_max, power_ratio, power_loss_ratio (can represent triangle or the "shaved-off" field, depending on p_at_hmax >/< power_ratio * h_max)

[sstroemer]

@Villyes what's your "slept on it" take on the internal component structure? Shall we do the "fuel -> electricity -> heat" idea?

And one more: You've used p_*** as well (again), so should we stick to power (or p_***) as it is now, or change to electricity? (I slightly favor power since it's a lot more common and sounds smoother, but strictly speaking I still think electricity would be the "correct" naming).

[Villyes]

what's your "slept on it" take on the internal component structure? Shall we do the "fuel -> electricity -> heat" idea?

I like it like this and the advantages: 1) follows the calculation as explained in the paper, 2) gives us the power_min constraint automatically, 3) gives us an easy way to use reduced efficiency in part-load.
In a potential documentation it should explain the "slight overhead" it produces in comparison to the current CHP core template.

And one more: You've used p_*** as well (again), so should we stick to power (or p_***) as it is now, or change to electricity? (I slightly favor power since it's a lot more common and sounds smoother, but strictly speaking I still think electricity would be the "correct" naming).

I think in the context of having 'power' and 'heat' it is pretty clear what 'power' refers to - I am for keeping 'power'.
However, should we change to 'power_max'? keeping it descriptive. I´ll change it in my first comment.

[Villyes]

This is the maybe-list:

'everything including ramp up/down'? [for my purpose: probably not necessary if CHP does not jump around between operation modes e.g. upper and lower boundary; has somebody analyzed this topic?]

efficiency_condensing_min:
efficiency_backpressure_min:

'everything else a unit provides'

[sstroemer]

I've started a placeholder template over at ait-energy/iesopt-project-template#3, where I think all future "proper" templates should be kept at (which helps separating template versions from IESopt.jl versions).

I'm keeping this one open, but detailed discussion could be moved to the draft PR where it can be attached directly to the code.

[nyashags]

Sorry I didn't contribute to the discussion sooner. But here are my additions and thoughts:

• @Villyes from what I've seen normally electrical efficiency is given, but I would recommend we make this clear in the parameter name even though this will make our parameter names longer
• Regarding efficiencies, maybe an option for our more elaborate CHP template would be to allow for thermal efficiency or overall efficiency to be provided as parameters and we do the calculations necessary to get to the electrical efficiency?
• I also think that when we speak of power and heat related to a CHP it is clear we mean electricity when talking of power and that it would be okay to keep it as power. However, in the discussion on conventions for parameter names we agreed on using power, power_lb and power_ub across templates to refer to the capacities of different units (this would be thermal capacity for a boiler for example) so maybe in that sense it would be a bit confusing why the default for the CHP is that power means thermal power.
• Regarding modes - I think for my wishlist for a CHP that can do everything and for the sake of completeness, then I think it would be nice to have the option to set the mode to 'condensing' if you'd like
• I also think that the set up of fuel --> electricity --> heat is nice and lines up well with what is actually happening which might actually make it easier to explain in the documentation compared to the current version

In terms of my wishlist for a CHP template, I agree with the list above and wuld wish for the following additions:

• thermal and overall efficiencies as optional parameters
• condensing mode as an option
• the possibility to have either an existing capacity and/or the possibility to invest in additional capacity (requires CAPEX as an input)
• Additional financial parameters like variable and fixed OPEX