| - | Sunnyvale | United States |
| (none) | Frampton Cotterell | United Kingdom |
| (none) | Tokorozawa | Japan |
| (none) | oobu-shi | Japan |
| (none) | San Diego | United States |
| (none) | Downers Grove | United States |
| (none) | Ville Saguenay | Canada |
| ABB | Bethlehem | United States |
| ABB AG | Mannheim | Germany |
| Administrador del Mercado Mayorista | Guatemala | Guatemala |
| Advanced Control Systems Inc. | Norcross | United States |
| advanced energy industries, inc. | Bend | United States |
| Advanced Power Technologies | Randolph | United States |
| Alabama Power Co. | Birmingham | United States |
| Alstom Grid | Stafford | United Kingdom |
| AltaLink Management LP | Calgary | Canada |
| Altus S.A. | São Leopoldo | Brazil |
| American Electric Power | Groveport | United States |
| American Superconductor | Middleton | United States |
| American Transmission Company | Cottage Grove | United States |
| American Transmission Company | Cottage Grove | United States |
| Andrew West, SCADA Consultant | St Lucia | Australia |
| Applied Systems Engineering, Inc. | Campbell | United States |
| ARC Informatique | Sevres | France |
| Arteche Medicion y Tecnologia | Zapopan | Mexico |