Here’s how wind powers 27,000 lights on the Rachel Carson Bridge

By December 5, 2016Blog
Closeup of Rachel Carson Bridge with rainbow colored lights

By Ron Gdovic PhD

CEO, WindStax

Energy Flow is powered by an advanced energy management system combining wind energy and Duquesne Light utility power to operate a dynamic digital light display. The system consists of sixteen WindStax wind turbines running four WindStax nano grids to create a microgrid. The link shows live information about the health and performance of one of the nano grids on the Rachel Carson Bridge.

RELATED: Click here to view real-time data and current conditions being reported from the weather station on the Rachel Carson Bridge

Functionally, wind energy is captured by the wind turbines, converted to electricity and stored in batteries. When the lighting display turns on, 24 volt direct current from the batteries is inverted to 120 volt alternating current to operate the lighting. The wind turbines continue to charge the batteries when the wind speed is above 8 miles per hour. Given the battery storage capacity, the microgrid also functions as a large uninterruptible power source. Should utility power be lost, the lighting will function for up to 12 hours even with no wind.

Rod Gdovic of WindStax inspects two wind turbines before final installation on the Rachel Carson Bridge.
Because wind is variable, the microgrid electronics switch to utility power if the wind generation and stored energy in the battery bank cannot keep up with the lighting load demand. When the batteries recharge, the system changes back to wind energy. The switch occurs in about 10 milliseconds.

Energy Flow uses sixteen 300 watt WindStax vertical axis turbines in clusters of four turbines per nano grid. The total output of the turbines on the bridge is 4,800 watts or 4.8kW. The total peak load of the lighting is 7kW with a working load of 3.2kW. Therefore, there will be times when wind energy production exceeds demand while utility power supplements any shortfall in battery storage.

Wind turbine on Energy Flow
A typical home uses about 10,000 kWh (kilowatt hours) per year. Energy Flow should produce approximately 10,800 kWh annually – enough to power the average US household on wind energy alone. In terms of reducing carbon monoxide emissions, that is equivalent to taking 1.6 passenger vehicles off the road, eliminating 18,191 miles driven, or reducing 8.4 tons of carbon dioxide equivalent from the environment annually.

Energy Flow represents a glimpse into the future of smart grid technology, blending traditional and alternative energy sources to create a seamless and reliable source of energy for the consumer.

RELATED: View a behind-the-scenes video showing how Energy Flow came together.