{"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","discovered_at":"2026-05-14T18:03:45.489281+00:00","generated_at":"2026-06-20T06:36:19.005861+00:00","sec_items":["5.02","9.01"],"event_type":"leadership","sentiment":"neutral","materiality_score":0.5,"calibrated_materiality_score":0.5,"confidence":"high","headline":"Tecogen appoints Abinand Rangesh as CEO; Benjamin Locke resigns as CEO and director","bullets":["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."],"urls":{"canonical":"https://secwatch.observer/filing/0001537435-23-000003","json":"https://secwatch.observer/filing/0001537435-23-000003.json","markdown":"https://secwatch.observer/filing/0001537435-23-000003.md","text":"https://secwatch.observer/filing/0001537435-23-000003.txt","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"},"model":{"generated_by":"deepseek-v4-flash:cloud@v2","generated_at":"2026-06-20T06:36:19.005861+00:00"},"review":{"review_status":"machine_generated","human_reviewed":false,"corrected":false,"correction_note":null,"correction_timestamp":null,"superseded_by":null,"related_filings":[]},"source_grounded_claims":[{"claim_id":"3ca84d6d0f","claim":"Abinand Rangesh was appointed as Chief Executive Officer at TECOGEN INC..","evidence_excerpt":"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_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1537435/000153743523000003/0001537435-23-000003-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"appointed"},{"label":"Role","value":"Chief Executive Officer"}],"fact_type":"executive_change"},{"claim_id":"d4c9dcc43d","claim":"Benjamin M. Locke resigned as Chief Executive Officer at TECOGEN INC..","evidence_excerpt":"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_source":"SEC 8-K Item 5.02","evidence_url":"https://www.sec.gov/Archives/edgar/data/1537435/000153743523000003/0001537435-23-000003-index.htm","confidence":0.95,"family_label":"Executive change","details":[{"label":"Action","value":"resigned"},{"label":"Role","value":"Chief Executive Officer"}],"fact_type":"executive_change"}],"license":"Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer"}