The market price (spot price) of electricity California utilities pay to energy producers can literally change every minute. Based on grid demand, the spot price of electricity can go substantially negative (as low as -$500/kwh) or substantially high ($400/kwh) when demand peaks. The pricing structure is incentive-based, so that the operators pay close attention to the cost of energy at any given moment.
Prices can drop so low that operators end up paying the utility for the power they put on the grid. Energy producers such as wind-farm operators must spin up or down electrical-generation equipment, literally, at a moment's notice to maximize profits and avoid negative price drops. But adding real-time monitoring and control to legacy equipment is tricky.
Bridging the OT/IT gap
To accomplish this, SCADA Solutions has leveraged IoT technologies to remotely monitor and automatically control wind turbines based on real-time market-pricing data and historical operation costs. SCADA Solutions combines off-the-shelf products and in-house-developed software to bridge the OT/IT gap and provide real-time monitoring and control of these remote assets—some of which are nearly 30 years old.
Intelligence and communication start at SCADA Solutions’ cloud-based WindCapture software, which uses a RESTful API to connect over the internet to California Independent System Operator (CAISO, the electrical authority in the state) and poll the spot price of electricity in real time. Using RESTful APIs is important in IoT applications, since most of the internet—mobile applications, social media, mashup tools, and automated business processes—relies on them for interoperability and communication.
Using the Opto 22 groov mobile operator interface, wind-farm operators can monitor the price of electricity through an app on their mobile device and manually ramp up or down electricity-generation at the wind turbine with the push of a smartphone button. Users can open a groov screen from the browser on their PC, mobile device, or even a big screen TV…they literally have their HMI in their pocket, wherever they are.
Pushing edge intelligence further
SCADA Solutions has pushed edge intelligence even further by storing vendor-specific turbine profiles in the Opto 22 PAC file system. The profiles are essentially a small database of information that lists how profitable each specific turbine is, based on historic operation costs and environmental conditions like wind speed. The PAC uses its built-in logic to calculate real-time profitability using several data points. First the PAC receives the spot price of electricity from the cloud. Then the wind speed is obtained from an anemometer at the turbine site. And finally the PAC analyzes the turbine profiles stored on its file system to determine the best rotor pitch and the most profitable times to start/stop wind turbines to maximize profit and reduce operating costs.
The wind turbines can also monitor their own physical health. Using vibration sensors connected to the turbine shaft and temperature sensors monitoring the turbine’s oil temperature, the PAC gauges what’s happening in the physical world. If the vibration of the turbine shaft approaches a preset unsafe threshold, the PAC automatically takes the turbine offline and notifies an operator via email or text. Operators maximize oil lifespan and schedule maintenance outages based on oil-temperature data aggregated and analyzed in the cloud.