Estimate BGE heat pump homes and apply CT rate impact analysis to Maryland #335

What

Estimate how many current heat pump homes BGE has, then run the rate impact analysis Lee is building for Connecticut with Maryland inputs. The result should show how much rates would go up for everyone else if BGE's heat pump customers moved to a heat pump rate.

Lee owns the code. This ticket covers the research and the Maryland-specific numbers.

Why

JPV expects to be cross-examined in Maryland on how much rates would rise for other customers. The same analysis is already being built for CT, so we can reuse it.

How (optional)

1. Find the programs

• Do a little research to name the heat pump install rebate programs available to BGE customers, both BGE-administered and otherwise.

2. Estimate current heat pump homes

• BGE won't have a direct count: its responses to CCAN DR 1-1 and 1-3 say it doesn't forecast heat pump adoption, and its subclass designations only show heating and non-heating loads.
• Starting point: OPC's EmPOWER comments report 10,070 BGE heat pump installations in 2025 (mdpsc_9705_opc_comments_empower_2025_q3_q4.md, Table 5).
• Add earlier years where available. Check whether installs equal homes, since one home may install more than one unit.
• Follow the same research approach as R2-181 in CT.

3. Apply the analysis

• Lee's CT work is on branch 333-ciec-requests-to-clf-sc-1-19-request-1, in reports/ct_hp_rates/ciec_requests/. It isn't merged yet, and JPV expects it to end up modular in the rates library with a standalone notebook.
• Maryland batch: md_20260910_w_rhp (reports/md_hp_rates/batch_config.yaml).
• Coordinate with Lee on when the code is ready for Maryland inputs. The research can start now.

Deliverables

• Named list of heat pump rebate programs available to BGE customers
• Estimate of current BGE heat pump homes, with sources and assumptions
• Maryland inputs for the analysis
• Maryland results: revenue shortfall, rate increase for other customers, and bill impact