At the Emerson Exchange conference in Austin, an oil and gas producer shared a story of automating natural gas wells and pipelines with renewable power sources.
The presenter opened describing some of the choices for renewable energy including solar panels and wind turbines. Based the latitude of the production fields, there was barely enough sunlight for the solar panels to collect and created electrical energy. They were also challenged with average winds speeds of only 4 meters/second. This was not enough wind on a consistent basis.
Of the two, the solar panels were a better option since they collected 90%+ of the energy in tests they conducted.
The architecture of the SCADA system is a ControlWave Express remote terminal unit (RTU) connected to the solar panel and battery bank collecting data from pressure and temperature transmitters. 75 watt solar panels were used to charge the battery banks. On some other installations with larger RTUs required, 400 watt solar panels were used.
For the natural gas pipelines, more I/O parameters were collected. These I/O were not only for monitoring, but for control in actuating valves along the pipeline. Data was transmitted on a real-time basis through radios to central facilities. The 20-watt radio was turned on a periodic basis to batch transmit data collected in the RTU.
One issue was snow covering the panels. Panels were mounted vertically to avoid snow accumulation. Even at this mounting angle, they could capture enough solar energy to recharge the battery banks. Energy use had to be carefully monitored and minimized so the batteries would not discharge fully in times of lack of sunlight.
You can connect and interact with other SCADA and RTU experts in the SCADA group in the Emerson Exchange 365 community.