In most commercial and institutional buildings, lighting may directly create 20% to 30% of the electric load and is typically a significant contributor to a facility's cooling load. When an electric chiller handles that load, it may add another 10% to the building's peak demand. Where variable-speed drives control fan speeds, extra cooling loads keep them running at higher speeds, pulling even more power.
As a result, lighting is often responsible for 40% or more of a building's total electric peak load. Being able to control a portion of that load in real time through a building management system (bms) could trim the peak demand charges levied by a utility or power supplier. Fortunately, several recent developments make this goal readily achievable.