Rural public facilities in Indonesia face significant energy efficiency challenges due to inadequate management systems, aging infrastructure, and limited technical capacity. This study develops a smart energy coordination platform integrating IoT sensors and wireless communication networks for five public facilities in Petumbukan Village, North Sumatra. Six-month continuous monitoring using power quality analyzers and IoT data loggers revealed 310.7 kWh/day total consumption with 0.43 load factor, 40.7 kW peak demand, and 1.27 diversity factor across facilities. Comprehensive energy audit identified 17.7 kW total losses (43.5% of peak load), with lighting inefficiency representing the primary concern at 8.5 kW (20.9% of system load). The proposed four-layer IoT architecture implements smart meters, environmental sensors, LoRaWAN communication, and edge computing devices for real-time monitoring and automated control. Multi-facility coordination algorithms leverage load diversity to achieve 22% annual energy savings (56,327 kWh) through optimized scheduling and demand management. System performance demonstrates 15% peak demand reduction, load factor improvement from 0.43 to 0.52, and sub-5-minute response times for automated load adjustments. The platform provides a technically feasible and replicable framework for rural electrification optimization in developing countries, addressing the gap between urban-focused smart grid solutions and rural infrastructure constraints.