Power Play: Incorporating DC Power Into Facilities
The quest for more efficient lighting systems in institutional and commercial facilities has spurred ongoing innovations in technology. Most solutions deepen the trend toward lighting and controls in becoming more highly dependent on solid-state, digital electronics and power conversions.
As a result, an increasing portion of the electricity used in lighting and related devices requires conversion of the building-available form of alternating current (AC) to direct current (DC). In many cases, this conversion can result in power-conversion losses of 5-20 percent, depending on the device being powered. Also, the power electronics required to make these conversions and to protect the downstream control and driver electronics decreases the reliability of the entire system.
On the power-generation side, a growing number of native DC renewable sources are being deployed on site in facilities, resulting in additional conversions because the power must be inverted to AC for distribution, then converted back to DC at the device level. The additional electronics employed in these conversions also decrease the reliability of the entire system.
Finally, recent weather, natural disasters, and faulty operations at major events also have drawn the attention of many maintenance and engineering managers to additional considerations concerning back-up power and off-grid — islanded — power. The relative simplicity and lower cost of DC power back-up systems have become an increasing focus in this regard.
In response to this new landscape for improved power-use efficiency and reliability, a growing number of managers are looking to revamp the traditional systems for power generation and delivery.