As the need for energy efficiency becomes more pronounced, the drive toward efficiency in the commercial sector will be impeded by its complicated mix of building sizes and uses, the complicated systems often used in commercial buildings, and the relative lack of understanding of operations factors impacting energy use and how to achieve efficiency.
In the United States, commercial energy use has increased from 10 to 17% or more of national energy use between the years 1960 and 2000. A significant reason for this increase is the low cost of energy relative to the other costs of conducting business, but the difficulty in understanding energy systems and energy use in commercial buildings is also an important contributing factor. Policy officials often have difficulty understanding discussions of the needs for improvements in commercial buildings.
As economies advance and commercial sector energy use begins to grow relative to other sectors, an improved understanding of methods of measuring commercial energy performance, and the means of achieving efficiency improvements in this sector, will be important in any drive toward efficiency.
One warning sign of the need to increase understanding of energy performance is an increase in the use of air conditioning in commercial buildings. When air conditioning use increases, energy system complexity and indoor space quality issues also increase significantly. If air conditioning use is increasing, any proposal for increased efficiency that relies heavily on thermal insulation should be treated warily, because insulation optimization becomes more difficult, and other system complexities tend to become much more important.
A warning should be given overall for energy standards for buildings, as they currently exist around the world, because, despite the existence and use of these standards for many years, the effect of standards has been only moderate in most cases. The shortcoming of existing standards is that they rely too heavily on simulation of expected performance, without conducting true empirical studies to verify the effectiveness of what the standards achieve. One major reason such empirical studies have been conducted in only limited and mostly ineffective fashion is that an empirical method of measuring energy performance of commercial buildings, although still adjusting for legitimate building use differences, has only recently been established in concept, only for certain building types, and not with the stated intent of being a performance standard (Energy Star label for buildings). Interestingly, however, if such energy performance standards existed, energy standards currently in use, with their typically complicated requirements, would not necessarily be needed any longer as standards.
Use of energy performance certificates may be necessary to overcome the difficulty users, occupants, code and policy officials, and owners have in understanding commercial energy use and performance. Without certification of energy performance, the complexity of systems and uses makes understanding energy performance by anyone other than an expert, and even by some experts, difficult. However, without increased understanding of the most appropriate means to normalize energy use for legitimate differences in building function and use, energy performance certificates may offer an unsatisfactory solution, due to inequities that will be obvious to many, if reasonable normalizations are not applied.
Increased energy efficiency in the commercial sector is an important piece of the national efficiency strategy in advanced economies, in which the priority for efficiency must be increased. Complexities in commercial buildings have made progress in energy efficiency for this sector less than desirable in notable cases. Fortunately, methods and know- ledge needed to increase success in this sector have begun to be developed, and better solutions can be offered in the near future to help increase energy efficiency in the commercial sectors of countries where the need is pressing.
