What Does Your Building's Electricity Cost Per Square Foot Say About Its Efficiency?
Making a building energy efficient has two benefits: it reduces the building's carbon footprint and annual utility bill. To get the best results in both cases, energy efficiency should be practiced as a science and not as a fashion; that is, companies should hire an energy efficiency consultant to perform and energy audit of their building (s) before moving forward with plans for efficient design, which in the absence of an efficiency consultant usually sums to one off projects that improve a building's efficiency in one area but not systematically, which should be the goal.
Determining the Ideal Electricity Cost Per Square Foot for your Building
For most companies, electricity is the single largest utility cost, in many cases accounting for upwards of 90 percent of a building's annual utility bill. Consequently, one of the core practices of an energy audit is calculating a building's electricity cost per square foot. A company's ideal electricity cost per square foot depends on several factors, including what type of building it is (eg industrial facility versus office building) and the climate it resides in. Once measurements are taken, they're often compared to the electricity cost per square foot of similar buildings in similar climates.
The largest advantage of having an efficiency consultant perform an energy audit is that it results in targeted solutions for your building's problems areas from greatest to least, which can be implemented on a priority basis. Without this knowledge, companies usually start by replacing what they think is their least efficient equipment with more efficient equipment. Sometimes companies guess correctly about what to replace. But they can also spend big money on solutions that do not address the biggest problem areas first.
In most commercial buildings, the largest source of electricity use is an interior lighting system, which accounts for roughly 60 percent of the average commercial building's annual electric bill. Second to interior lighting is an HVAC system, which accounts for roughly 30 percent of a building's electrical use. As a result, interior lighting and HVAC systems are commonly targeted for energy efficient retrofitting, a process where a building's systems are outfitted to accommodate more efficient equipment.
In an interior lighting system, traditional lamps and ballasts are typically replaced with more efficient ones, and an automatic lighting control system may be added to the new lighting. In HVAC systems, traditionally oversized elements, such as chillers and air distribution fans are downsized, thus reducing their energy usage. By hiring an energy efficiency consultant and taking a systematic approach to energy efficiency, many companies realize a 50 percent or more reduction in their annual utility bill.