Over 100 years ago, America’s first direct current (DC) power grid began coursing beneath Pearl Street in lower Manhattan. Developed in the 1880's by the Edison Electric Illuminating Company, the world’s first commercial power plant was used to provide electric light to approximately 800 of Edison’s early commercial customers. The location at Pearl Street in New York was a strategic one - DC power did not efficiently travel long distances - and this inefficiency would eventually put Edison on the losing end of “A War of The Electric Currents”.
More than a century later, alternating current (AC) is the global standard for both long distance transmission and the distribution of power within commercial buildings and homes. Yet, today’s higher voltage AC mains have not served as an effective medium for digital communications, and most attempts to create power-line communications on AC wiring have proven to be difficult, complex and unreliable.
As a result, most commercial and residential electrical applications do not communicate over the electrical wiring, and any network or system-based techniques to optimize power consumption, or even measure electric power at the application level, must be added as expensive and cumbersome overlays. In essence, without system communications, these electric loads all connect to an “analog” power network – one that can deliver power as needed but cannot know why devices came on, how long they will stay on, the optimum power to provide, if they are failing, over-heating, power losses or problems in the wiring, or even how much power each application is using.
Perhaps the greatest irony is that there are now several household and commercial applications that are inherently “digital” in nature, and that require DC power, including a compelling and new lighting source, light emitting diode (LED) lighting. These digital applications could utilize a systems approach to improve energy efficiency, but remain plugged into a strictly analog AC power line.
Redwood’s vision is to go all the way back to Edison’s first electric lighting system and start again. With LED lighting requiring low voltage, DC current as it’s power source, we have an opportunity to bring back DC wiring for commercial lighting. More importantly, on the same low voltage, DC wires, we can build a digital network to manage and efficiently optimize the lights, and going forward, provide data and control information for heating, venting, air conditioning, plug loads, window shading, and potentially just about everything else that uses power in a building.