A message bus is utilized for energy management/control. The publish/subscribe message bus present between site gateways, a central server farm, and other entities, facilitates exchange of messages pertaining to management and control of power generation and/or storage. On-site publishers/subscribers can include, e.g., PV inverters, battery devices, energy meters, etc. Non-site specific publishers/subscribers can include, e.g., web clients, database servers (for logging), and various server components of the message bus. Messages exchanged between publishers and subscribers can include control messages (e.g., begin charging battery X) and measurement messages (e.g., the current charge of battery X is Y). Embodiments may implement logic at a site gateway prioritizing transmission of messages to local site devices. Thus where a gateway cannot simultaneously transmit device control messages and device data acquisition messages (e.g., due to processing burden or congestion), site gateway logic can prioritize transmission of the control messages over the locally-generated data acquisition requests.