| Org Name | Org Type | City | Website | AET Category |
| 1st Choice Home Improvement, Inc. | AET Supplier | Shelby Township, MI | www.michfirstchoice.com | Energy Efficiency |
| 21st Century Plastics Corp | AET Supplier | Potterville, MI | | Wind |
| 2ktool LLC | AET Supplier | Wyoming, MI | 2ktool.com | Wind |
| 3G Services Inc. | AET Supplier | Taylor, MI | http://www.3gservicesinc.com | Wind |
| 3M Fuel Cell Components | AET Supplier | Livonia, MI | solutions.3m.com/en_US | Fuel Cells |
| A & B Machining | AET Supplier | Fruitport, MI | challengeprecision.com | Wind, Batteries/Energy Storage, CO2 Sequestration, Alternative Fuels for Power Generation |
| A J Williams Manufacturing Co | AET Supplier | Jackson, MI | NO Website Found | Wind |
| A&D Technology Inc. | AET Supplier | Ann Arbor, MI | www.aanddtech.com | Wind |
| A.B. Heller, Inc. | AET Supplier | Milford, MI | www.abheller.com | Wind |
| A.C Mechanical Experts, Inc. | AET Supplier | Armada, MI | | Energy Efficiency |
| a.j. Veneklasen | AET Supplier | Grand Rapids, MI | ajvinc.com | Wind |
| A-1 Mechanical | AET Supplier | Lansing, MI | www.a1mechanical.com | Energy Efficiency |
| A123 Systems | AET Supplier | Ann Arbor, MI | www.a123systems.com/#/company/contact/ | Batteries/Energy Storage |
| A3C – Collaborative Architecture | AET Supplier | Ann Arbor, MI | www.a3c.com | Energy Efficiency |
| Abb, Inc. | AET Supplier | Auburn Hills, MI | www.abb.com | Wind |
| Ability Mfg & Eng Co. | AET Supplier | Fennville, MI | www.ameco.org | Wind |
| Abode Building & Remodeling | AET Supplier | Portage, MI | www.abodebuilding.com/default.asp | Solar PV |
| AC Foundry Inc. | AET Supplier | Battle Creek, MI | www.acfoundry.com | Wind |
| AccuBilt Inc. | AET Supplier | , MI | www.accubilt.com | Wind |
| Accurate Molding & Engineering | AET Supplier | Sparta, MI | | Wind |