---
schema_version: "secwatch.filing_event.v1"
accession: "0001537435-23-000003"
form_type: "8-K"
ticker: "TGEN"
cik: "0001537435"
company_name: "TECOGEN INC."
filed_at: "2023-01-30T23:59:59+00:00"
generated_at: "2026-06-20T06:36:19.005861+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Tecogen appoints Abinand Rangesh as CEO; Benjamin Locke resigns as CEO and director

## Summary
- Benjamin Locke resigned as CEO and director effective Jan 30, 2023; entered into a Consulting Agreement for ongoing advisory.
- Dr. Abinand Rangesh appointed CEO effective Jan 30, 2023, while continuing as CFO.
- Rangesh has been with Tecogen since 2016, holding roles in sales, business development, strategy; previously CFO and Board member.
- Lead Director John Hatsopoulos expressed confidence in Rangesh's blend of strategy, engineering, and finance skills.

## SEC filing metadata
- accession: 0001537435-23-000003
- form_type: 8-K
- ticker: TGEN
- cik: 0001537435
- company_name: TECOGEN INC.
- filed_at: 2023-01-30T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1537435/000153743523000003/0001537435-23-000003-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1537435/000153743523000003/tgen-20230130.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001537435-23-000003
- JSON: https://secwatch.observer/filing/0001537435-23-000003.json
- Plain text: https://secwatch.observer/filing/0001537435-23-000003.txt

## Key facts
- Executive change
  Abinand Rangesh was appointed as Chief Executive Officer at TECOGEN INC..
  - Action: appointed
  - Role: Chief Executive Officer
  source text: On January 30, 2023, Tecogen Inc. (the “Company”) issued a press release announcing that the Company’s Board of Directors appointed Dr. Abinand Rangesh to serve as the CEO of the Company effective January 30, 2023.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1537435/000153743523000003/0001537435-23-000003-index.htm
- Executive change
  Benjamin M. Locke resigned as Chief Executive Officer at TECOGEN INC..
  - Action: resigned
  - Role: Chief Executive Officer
  source text: Also on January 30, 2023 Benjamin M. Locke resigned as CEO and as a director of the Company and its affiliates effective January 30, 2023
  evidence_url: https://www.sec.gov/Archives/edgar/data/1537435/000153743523000003/0001537435-23-000003-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.