| Levinson DanielDirector, 10% owner · 2 transactions | — | 2.21M†as of Dec 2006 | — | 773.3K | — |
| MSR I Sbic LP10% owner · 4 transactions | — | 2.21M†as of Dec 2006 | — | 868.7K | — |
| Scott Richard L10% owner · 6 transactions | — | 1.32M†as of Dec 2012 | — | 200.0K | 350.0K |
| Canino Joel MVice Chair. Gemma Power System, 10% owner · 191 transactions | — | 935.7Kas of Oct 2008 | — | — | 595.1K |
| Thomas Kevin10% owner · 2 transactions | — | 715.8Kas of Dec 2006 | — | — | 960.0K |
| Bosselmann Rainer HDirector · 183 transactions | — | 196.7K | 250.3K | 19.1K | 481.6K |
| Griffin William F JrDirector, GEMMA, NON-EXECUTIVE CHAIRMAN · 397 transactions | — | 193.6K† | 21.0K | — | 1.19M |
| Quinn James WDirector · 47 transactions | — | 51.8K† | 88.2K | 71.7K | 151.0K |
| Watson David HibbertPRESIDENT AND CEO, Director · 52 transactions | — | 41.4K† | 141.3K | 2.4K | 103.7K |
| Leimkuhler William F.Director · 48 transactions | — | 38.0K† | 95.2K | 4.0K | 90.7K |
| Collins Charles Edwin IVCHIEF EXECUTIVE OFFICER, GEMMA · 50 transactions | — | 30.3K | 89.2K | — | 58.8K |
| Sherras Brian RDirector · 3 transactions | — | 28.0Kas of Jan 2020 | 10.0K | 28.0K | 10.0K |
| Flanders CynthiaDirector · 39 transactions | — | 23.1K† | 98.3K | 8.5K | 97.7K |
| Martin Daniel LPresident, Gemma Power Systems · 46 transactions | — | 20.1Kas of Jun 2016 | 30.1K | — | 90.0K |
| Crumpton Henry ADirector · 10 transactions | — | 20.0Kas of Jun 2017 | 40.0K | — | 50.0K |
| Jeffrey John Ronald Jr.Director · 28 transactions | — | 10.5K† | 38.9K | 8.0K | 36.4K |
| Trudel Arthur FFormer Senior VP and CFO · 129 transactions | — | 10.0Kas of Apr 2015 | — | 45.9K | 190.0K |
| Mitchell W G ChampionDirector · 24 transactions | — | 10.0K†as of Dec 2024 | 58.3K | — | 68.3K |
| Deily Richard HCompliance Officer, Former CFO · 26 transactions | — | 7.8K | 40.2K | 1.0K | 33.4K |
| Getsinger Peter WDirector · 57 transactions | — | 5.3K† | 75.5K | 4.3K | 66.2K |
| Koilpillai Mano SFormer Director · 11 transactions | — | 5.0Kas of Jul 2024 | 13.5K | — | 8.5K |
| trebilcock Terrance ColinPRESIDENT, GEMMA POWER SYS. · 1 transaction | — | 1.7Kas of Apr 2022 | 1.7K | — | — |
| Sweeney KarenDirector · 5 transactions | — | 1.5K | 2.2K | — | 690 |
| Baugher Joshua ScottChief Financial Officer · 9 transactions | — | 1.5K | 2.5K | — | 1.4K |
| Larroque Alexander LisaDirector · 3 transactions | — | 883 | 1.2K | — | 350 |
| Desoto JordanDirector · 26 transactions | — | 200as of Apr 2009 | 15.0K | — | 15.0K |