Add ability to build network for individual/groups of states

[ktehranchi]

Feature Request

For regional planning it would be useful to implement a feature that builds individual states rather than entire interconnections.

Suggested Solution

• Filter states in build_base_network, build_shapes, and build_bus_regions
• Add electricity would need to only add plants that are located in the states

Additional Info

No response

[jpvelez]

Besides filters, wouldn't we need some way to configure what level of clustering to apply to the grid outside the state?

[ktehranchi]

Yep- I'm doing some research now on which style of external node representation makes the most sense for your use-case. Stand-by while I do some reading and gather thoughts from my colleagues who do more IRP modeling.

These are the three options:

1. Split off a State completely from the rest of the system- where external nodes can be bought from / sold to at a defined market price
2. Split off a State + its adjacent neighbors- where those adjacent neighbors can still have renewable resource be built-in and exported to the given State. But not external market prices are defined.
3. Model entire interconnect but aggregate all non-studied nodes together. This way all renewable resource across the interconnect are represented, and could either allow build or could be restricted.

[ktehranchi]

So, all three options seem useful for modeling different states/scenarios. But I think a starting point would be option 1:

Split off a State completely from the rest of the system- where external nodes can be bought from / sold to at a defined market price

For instance, here is a map of the transmission topology used by Pacificorp for their 2023 IRP. In this case, the transmission topology allows for splitting off user-selected regions (blue and orange bubbles). The yellow bubbles represent pricing nodes that would be exogenously defined.

[ktehranchi]

I can see two routes for getting this done:

First Option Filtering out regions from the start in build_base_network, and editing all downstream functions to ensure demand, generators, renewable profiles, GIS shapes are modified accordingly to not add incorrect loads and generators. Work involved:

1. Adding a function at the end of build_base_network which removes all buses, lines, transformers in build_base_network.
2. Add function to calculate Load Allocation Factors (LAF) for correctly distributing EIA930 data similar to how we do it for EFS LAFs in build_base_network.
3. Modifying build_shapes to only build the region of interest shapes.
4. Modifying add_electricity to only add generators in the region of interest
5. Modify build_demand for all read strategies (EIA, EFS, EULP).

Pros: Faster run-time for build_renewable_profiles. Smaller network size throughout workflow. Cons: Lots of code to update. Missing out on adding options for including external node renewable profiles and transmission capacity

Second Option Filter out regions after cluster_network. Work involved:

1. Write script at the end of cluster_network to either remove buses, lines, loads, generators, links which are connected to external regions.
2. Option to add a link to user defined external pricing nodes at a given marginal cost

Pros: Avoid many code changes upstream in the workflow. Allows more flexibility for including information on external renewable profiles. Con: Longer runtime since you have to build the entire network.

Thoughts: My hunch is that option two is the way to go even if the workflow would take longer to build.

[jpvelez]

Thanks, this is super useful!

Another consideration: does either option make it easier to add modeling approaches 2 (Split off a State + its adjacent neighbors) and 3 (Model entire interconnect but aggregate all non-studied nodes together) later—assuming we want to do that?

[ktehranchi]

good Q: option 2 will be compatible with modeling approaches 2 and 3.

2: Split off a State + its adjacent neighbors- where those adjacent neighbors can still have renewable resource be built-in and exported to the given State. But not external market prices are defined.

Is an extension of 1, and we would accept a list for filter regions instead of just one region.

3: Model entire interconnect but aggregate all non-studied nodes together. This way all renewable resource across the interconnect are represented, and could either allow build or could be restricted.

This is a quick change (<1 line of code). We would just rename the regions which are external into "external regions"

[jpvelez]

Just wanted to flag a potential resource: a study of New York State done by Vibrant Clean Energy

They say:

Existing transmission corridors between New York and neighboring states are modeled as imports and exports with energy prices provided by a background modeling scenario (“CEDER”). 6

And this is the background modeling scenario: https://www.vibrantcleanenergy.com/wp-content/uploads/2020/12/WhyDERs_TR_Final.pdf