Fine-grained remote monitoring, control and pre-paid electrical service in rural microgrids

In this paper, we present the architecture, design and experiences from a wirelessly managed microgrid deployment in rural Les Anglais, Haiti. The system consists of a three-tiered architecture with a cloud-based monitoring and control service, a local embedded gateway infrastructure and a mesh network of wireless smart meters deployed at 52 buildings. Each smart meter device has an 802.15.4 radio that enables remote monitoring and control of electrical service. The meters communicate over a scalable multi-hop TDMA network back to a central gateway that manages load within the system. The gateway also provides an 802.11 interface for an on-site operator and a cellular modem connection to a cloud-backend that manages and stores billing and usage data. The cloud backend allows occupants in each home to pre-pay for electricity at a particular peak power limit using a text messaging service. The system activates each meter within seconds and locally enforces power limits with provisioning for theft detection. We believe that this fine-grained micro-payment model can enable sustainable power in otherwise unfeasible areas. This paper provides a chronology of our deployment and installation strategy that involved GPS-based site mapping along with various network conditioning actions required as the network evolved. Finally, we summarize key lessons learned and hypothesis about additional hardware that could be used to ease the tracing of faults like short circuits and downed lines within microgrids.