---
type: "Bill"
title: "Public Utilities – Thermal Energy Network Systems – Authorization and Establishment (Working for Accessible Renewable Maryland Thermal Heat (WARMTH) Act)"
description: "Public Utilities – Thermal Energy Network Systems – Authorization and Establishment (Working for Accessible Renewable Maryland Thermal Heat (WARMTH) Act)"
jurisdiction: "us/states/md"
legislature: "Maryland General Assembly"
session: "2024"
identifier: "HB 397"
citation: "Maryland HB 397 (2024)"
classification: ["bill"]
subjects: []
status: "enacted"
primary_sponsors: ["Charkoudian"]
version_count: 4
action_count: 17
vote_count: 3
first_action: "2024-01-17"
last_action: "2024-05-09"
source: "openstates"
source_identifier: "ocd-bill/f99b21b6-3f58-4ed9-82ab-d68321c1be86"
source_url: "http://mgaleg.maryland.gov/mgawebsite/Legislation/Details/hb0397?ys=2024RS&search=True"
source_hash: "b7e56f85ca1bafcdb1110987ab43c3fd85ac3f30702489a8ef4fc8a61d9ce5df"
vintage: "2026-07-01"
source_snapshot: "https://data.openstates.org/daily/2026-07-01/public.pgdump"
retrieved_at: "2026-07-06"
confidence: "reported"
tags: ["legislation", "bill", "us-md"]
---

# Maryland HB 397 (2024) — Public Utilities – Thermal Energy Network Systems – Authorization and Establishment (Working for Accessible Renewable Maryland Thermal Heat (WARMTH) Act)

## Version chain

The bill's text revisions, in order — the diff chain from filing to enrollment.

1. **Chapter - Public Utilities – Thermal Energy Network Systems – Authorization and Establishment (Working for Accessible Renewable Maryland Thermal Heat (WARMTH) Act)** (committee substitute) — [source](http://mgaleg.maryland.gov/2024RS/Chapters_noln/CH_564_hb0397e.pdf)
2. **Enrolled - Public Utilities – Thermal Energy Network Systems – Authorization and Establishment (Working for Accessible Renewable Maryland Thermal Heat (WARMTH) Act)** (committee substitute) — [source](http://mgaleg.maryland.gov/2024RS/bills/hb/hb0397e.pdf)
3. **First - Public Utilities – Thermal Energy Network Systems – Authorization and Establishment (Working for Accessible Renewable Maryland Thermal Heat (WARMTH) Act)** (committee substitute) — [source](http://mgaleg.maryland.gov/2024RS/bills/hb/hb0397f.pdf)
4. **Third - Public Utilities – Thermal Energy Network Systems – Authorization and Establishment (Working for Accessible Renewable Maryland Thermal Heat (WARMTH) Act)** (committee substitute) — [source](http://mgaleg.maryland.gov/2024RS/bills/hb/hb0397t.pdf)

## Votes

- On Third Reading — **99–38** (pass) · lower
- On Third Reading (Amend) — **36–9** (pass) · upper
- On Third Reading and Final Passage (Hse concurred) — **98–34** (pass) · lower

## Sponsors

- Charkoudian — primary (person)

## Timeline

The legislative action history — every referral, reading, and vote.

- **2024-01-17** First Reading Economic Matters `referral-committee`
- **2024-02-01** Hearing 2/22 at 1:00 p.m.
- **2024-03-07** Favorable with Amendments Report by Economic Matters `committee-passage-favorable`
- **2024-03-08** Favorable with Amendments { `committee-passage-favorable`
- **2024-03-08** Second Reading Passed with Amendments
- **2024-03-12** Third Reading Passed `passage`
- **2024-03-13** Referred Education, Energy, and the Environment `referral-committee`
- **2024-03-29** Favorable with Amendments Report by Education, Energy, and the Environment `committee-passage-favorable`
- **2024-03-29** Favorable with Amendments { `committee-passage-favorable`
- **2024-03-29** Motion Laid Over (Senator Hershey) Adopted
- **2024-04-01** Favorable with Amendments { `committee-passage-favorable`
- **2024-04-01** Second Reading Passed with Amendments
- **2024-04-02** Third Reading Passed `passage`
- **2024-04-05** House Concurs Senate Amendments
- **2024-04-05** Third Reading Passed `passage`
- **2024-04-05** Passed Enrolled
- **2024-05-09** Approved by the Governor - Chapter 564 `executive-signature`

## Source

OpenStates / OpenCivicData bulk snapshot [2026-07-01](https://data.openstates.org/daily/2026-07-01/public.pgdump); origin `ocd-bill/f99b21b6-3f58-4ed9-82ab-d68321c1be86`. Confidence: reported (aggregated from official Maryland legislature records).