A workspace energy management method and system control the power state of workspace appliances using multi-factor presence detection and mobile phone identity verification. Multifactor presence detection substantially reduces the risk that workspace appliances will be powered-up in response to erroneous detection of presence at the workspace (e.g., false positive). Mobile phone identity verification, which verifies that the office worker's mobile phone is at the workspace (and thus that the office worker is also likely at the workspace) before workspace appliances are powered-up, prevents workspace appliances from being inadvertently powered-up by personnel other than the office worker, but without compromising worker privacy.