[RenewableEnergyAccess.com] SunWize Technologies and SEC Automation recently completed a project to power dissolved oxygen (D.O.) monitoring sites at two hydro plants for the Indiana Utility Regulatory Commission. SunWize engineered solar electric systems operate integrated units of spread spectrum radios and D.O. analyzers. Both aquatic plants and animals depend on dissolved oxygen for survival. Dissolved oxygen concentrations are influenced by many factors including water temperature, the rate of photosynthesis, the degree of light penetration, the degree of water turbulence or wave action, and the amount of oxygen used by respiration and decay of organic matter. Measuring dissolved oxygen determines the suitability of a stream for fish and other aquatic organisms. EC’s customer was in need of an alternative source of power in lieu of the high cost and non-feasibility of commercial power installation for the remote locations along the river. SunWize and SEC Automation agreed that 123-watt solar systems would provide sufficient power for the monitoring sites. Two separate systems consisting of two solar powered remote radios, D.O. analyzers and a master ModBus radio were installed at key locations along the river. The analog signal outputs of D.O. analyzers are wired directly into RTU/radios. The remote radio units transmit the signals to a central ModBus gateway radio which interfaces with an existing SCADA system to monitor and provide historical trends of the collected data.