Allow Network Charges

[ADGEfficiency]

@rdmolony

This PR adds the ability to optimize for a network charge.

It required adding in the ability to supply custom interval data, to use with a custom objective function that sets up the network charge.

Features:

• adds custom interval data to the __init__ of assets and the site.

Other changes:

• makes the default for including a spill asset in asset.__init__ to False.

TODO:

• rename all use of extra interval data to custom interval data,
• document the custom interval data into customization.interval data,
• document the network charges into use_cases.network_charges,
• add include_spill: bool = False to all assets.

[ADGEfficiency]

The rough idea is:

import energypylinear as epl

site = epl.Site(
    assets=[
        epl.Battery(
            power_mw=2, capacity_mwh=4, efficiency_pct=0.9
        ),
    ],
    electricity_prices=[100, 1000, -20, 40, 45],
    network_charge=[0, 300, 300, 0, 0],
)
objective = {
    "terms": [
        {
            "asset_type": "site",
            "variable": "import_power_mwh",
            "interval_data": "electricity_prices",
        },
        {
            "asset_type": "site",
            "variable": "export_power_mwh",
            "interval_data": "electricity_prices",
            "coefficient": -1,
        },
        {
            "asset_type": "site",
            "variable": "import_power_mwh",
            "interval_data": "network_charge",
        },
    ]
}
site.optimize(objective)

[rdmolony]

Thanks Adam, the Site API has remained really minimal.

I understand that Site has now become generalised such that I can pass any interval data as a keyword argument & use it in my custom objective function.

---

I found it a bit tricky to nail down how network_charge is used by the optimizer ->

network_charge is passed via **kwargs to Site. In Site.__init__ it is appended to site.cfg.interval_data at runtime in validate_interval_data rather than during the creation of the site.cfg object in SiteConfig via SiteIntervalData.

Is pydantic a blocker for adding these custom fields to SiteIntervalData?

Dynamic model creation looks a little awkward - https://docs.pydantic.dev/latest/concepts/models/#dynamic-model-creation

interval_data is unpacked for use in the objective function in Site.optimize > self.optimizer.objective via add_simple_terms, add_two_variable_terms & add_many_variables_terms which use terms from the objective dict created by the user to access site.cfg.interval_data via getattr.

So this interval data only impacts the objective function?

---

Unfeasible simulations are enabled via include_spill, why?