City Council, Fiscal Years 2005–08 Table 3.8 Energy Consumption in Cities: Main Sectors and Clusters

in lighting, cooling, heating, or refrigeration). The critical factor is energy effi ciency, which refers to the adoption of improved technologies and practices to reduce the energy required to provide a similar level of energy output or service provision. In the urban context, it is important to assess the amount of useful energy that may be extracted from the primary source, delivered to end users, and turned into energy services.5 In buildings, energy effi ciency also implies reducing energy needs by improving the structural design and use of materials.6

A recent accounting of urban energy use conducted by the International Energy Agency delineated all energy-consuming activities within a city (IEA 2008). Based on this accounting, urban energy applications may be lumped into four broad categories: industry, transportation, municipal services, and buildings. A breakdown of these categories is presented in table 3.8.

Buildings that do not fi t in the fi rst three categories include a broad spectrum of structures ranging from single-family houses and apartment buildings to schools, hospitals, offi ces, and shopping malls. Factory buildings are excluded. For statistical purposes, buildings are usually divided into residential and commercial buildings. Residential buildings, which account for most of the urban building stock, are well defi ned as owner- or renter-occupied houses or apartments. Commercial buildings are diverse and usually include offi ce buildings, shopping malls, supermarkets, hotels, and other buildings that host commercial or public entities. Government buildings are separately identifi ed in table 3.8 because they represent special opportunities for sustainable energy interventions by city governments.

Typically, urban energy use in serviceoriented cities in developed countries is dominated by buildings and transportation, which account for two-thirds or more of energy consumption. In rapidly industrializing developing countries, such as China, industrial energy use is often predominant in large cities. Even in Beijing, one of the most modern, high-income cities in China, manufacturing still accounted for about half of all energy consumption in 2006 (IEA 2008). In general, buildings and transportation are the most rapidly growing energy sectors in cities in developing countries. They are also the sectors in which sustainable energy measures may have the greatest impact. Countries with a growing middle class typically show explosive growth in the use of electricity for

Table 3.8 Energy Consumption in Cities: Main Sectors and Clusters

CITY GOVERNMENT SUSTAINABLE ENERGY

SECTOR/CLUSTER CATEGORY SUBCATEGORY INTERVENTION, POTENTIAL LEVERAGE Industry Manufacturing Indirect, relatively weak Construction Indirect, relatively week Transport Private motor vehicles Indirect, relatively weak Commercial motor vehicles Indirect, relatively weak Public transit systems Direct, strong Government motor vehicles Direct, strong Municipal services Water supply and wastewater treatment Direct, strong Solid waste management Direct, strong Public lighting and traffi c lights Direct, strong Buildings Government buildings Direct, strong Commercial buildings (nongovernment) Indirect, strong in new construction Residential buildings Indirect, strong in new construction

Source: Author compilation (Feng Liu).