Add Optional Costs for Existing Boiler and Chiller

[Bill-Becker]

Add installed cost input options for ExistingBoiler and ExistingChiller which are also in the BAU scenario, to represent upgrades/replacements needed for those, which can then be avoided with investment in DERs.

Two cost options are implemented (swap out _per_mmbtu_per_hour with _per_ton for the analogous ExistingChiller options):

1. installed_cost_per_mmbtu_per_hour which estimates the cost based on the ExistingBoiler size needed for the scenario. We also include the input max_thermal_factor_on_peak_load in the size/cost needed (default is 1.25), so that effectively adds e.g. 25% to the size and cost based on the used/needed amount of ExistingBoiler. For example, if the BAU case needs 2 MMBtu/hr boiler, but the optimal case only needs 1 MMBtu/hr, the optimal case will have half the cost as the BAU case for the ExistingBoiler.
2. installed_cost_dollars which is not dependent on the size needed, and the optimal scenario will incur this entire cost if any size/amount of the ExistingBoiler is needed still. So the optimal case needs to not use any of the ExistingBoiler to avoid this cost. Note, for GHP which cannot serve DomesticHotWaterLoad by default, the preference may be to use Option 1 so that the incurred ExistingBoiler cost is only for serving DHW load. Or, the user can input installed_cost_dollars that just represents the installed cost of the boiler(s) for hot water heating.

Note, no incentives or discounting is applied to these installed cost inputs, so they are meant to be in terms of "net present" cost.

[atpham88]

@Bill-Becker can you also update the REopt.jl wiki with these additional inputs (if you haven't already updated it somewhere else that I miss)?

[Bill-Becker]

@Bill-Becker can you also update the REopt.jl wiki with these additional inputs (if you haven't already updated it somewhere else that I miss)?

So I think the Go-To place for seeing inputs and outputs would be the REopt.jl documentation page, and since I added the new inputs to the ExistingBoiler and ExistingChiller doc strings (above the structs), they will be viewable once this gets merged in. This is the version of the docs page that I spun up locally to confirm they will be in there:

[atpham88]

Everything looks good to me. Thanks very much Bill! I ran a bunch of tests with boiler and chiller in BAU-only and also in optimal cases and the sizes and capital costs are calculated correctly. There's some conflicts to resolve but after that it should be good to merge in.

[atpham88]

@Bill-Becker can you also update the REopt.jl wiki with these additional inputs (if you haven't already updated it somewhere else that I miss)?

So I think the Go-To place for seeing inputs and outputs would be the REopt.jl documentation page, and since I added the new inputs to the ExistingBoiler and ExistingChiller doc strings (above the structs), they will be viewable once this gets merged in. This is the version of the docs page that I spun up locally to confirm they will be in there:

I see these updates in the existingboiler.jl now. I originally thought we have to update a separate doc but this is better. Thanks.