Standard for dc power distribution released

EMerge Alliance released the EMerge Alliance Standard, which the association claims is the first to provide a roadmap for the use of low-voltage dc power in commercial building interiors. The standard is said to establish a more efficient means of powering the rapidly increasing number of digital, dc-powered devices found in today's workplaces, such as sensors, lighting, and IT equipment.

December 1, 2009

    EMerge Alliance released the EMerge Alliance Standard, which the association claims is the first to provide a roadmap for the use of low-voltage dc power in commercial building interiors.

    The standard is said to establish a more efficient means of powering the rapidly increasing number of digital, dc-powered devices found in today’s workplaces, such as sensors, lighting, and IT equipment. It creates an integrated, open platform for power, interior infrastructures, controls, and peripheral devices to facilitate the hybrid use of ac and dc power within buildings. In the standardized scheme, ac power is converted to low-voltage dc for room-level distribution, which is intended to eliminate numerous device-level ac-to-dc power converters.

    The standard also provides for an optional connection to on-site alternative power generation such as solar panels and micro-turbines, which historically have required conversion to ac using inverters. Using native dc power generated from on-site sources to drive dc loads more directly can dramatically improve building efficiency, reduce energy costs, and reduce environmental footprints, according to EMerge Alliance.

    “The EMerge Alliance Standard sets the stage for a new era in power sourcing, distribution, and management in commercial buildings,” said Alliance chairman BrianPatterson. “While we advocate increased use of native dc power, the Alliance is not interested in reliving the epic Edison and Westinghouse battle over ac versus dc technologies. Rather, we’ve set out to find better and more practical ways of getting the most out of both.”

    The Alliance is establishing a third-party registration and evaluation program scheduled to begin this fall for labeling products based on the standard. This program will benefit Alliance members, system specifiers, and building owners by ensuring that products will be available from the EMerge Alliance membership base and that all products will be easily identifiable in the market.

    According to EMerge Alliance, the standard defines physical and electrical requirements intended to achieve the following goals:

    • Reduce energy losses by eliminating device-by-device electrical conversions from ac power to dc power

    • Use of safe Class2 power levels wherever practical, as defined by the National Electrical Code

    • Broad capabilities for faster and simpler moves, adds, and changes in occupied spaces

    • Movement toward interoperable device-level controls and Smart Gridintegration at the building level

    • Easier integration of native dc power sources such as solar, wind, fuel cell, and batteries, with traditional ac power sources

    • Flexibility to implement new energy-saving devices—such as LED lighting and controls, and energy-saving technologies such as renewable power sources—more efficiently and effectively.

    A public overview version of the standard and answers to frequently asked questions are available at www.EMergeAlliance.org . The full EMerge Alliance Standard is available to Governing, Participating, and General Members of the Alliance.