Table 3.14 A Comparative Economic Analysis of Selected Streetlighting Systems

Many cities in developing countries have a pressing need to expand water supply and wastewater treatment capacities. The reclamation of runoff water and the on-site treatment of domestic wastewater are increasingly prevalent in new real estate development projects. Such practices, if properly confi gured within urban water and wastewater networks, may enhance overall energy effi ciency, while relieving the pressure on scarce freshwater resources.

Public lighting: Public lighting is often considered an essential public service that enhances economic activity and improves the quality of life (for example, by reducing crime and vehicular accidents). Streetlights may be provided more eff ectively and extensively by using energyeffi cient lighting technologies, which are now cheaper and more plentiful. However, the procurement of lamps is often based on consideration of the initial costs without taking into account the impact on recurring energy bills. To varying degrees, municipal governments possess limited capital budgets to replace lighting; lack credible information on alternatives; and, in some cases, fail to pay electricity bills for streetlighting regularly. To illustrate the range of options available in streetlighting, table 3.14 examines the costeff ectiveness of alternative systems that were considered by the State of New York in 2002.

Streetlamp retrofi ts may potentially save 30 to 40 percent of typical energy costs and, depending on cost structures and available lamps, may have payback periods of less than three years. Installing time clocks and automated control systems and redesigning systems (to eliminate overlighted and underlighted areas) may achieve additional energy savings. In India, the State of Tamil Nadu issued a tender for seven municipalities to be retrofi tted to reduce energy use in public lighting and water pumping. Through an urban infrastructure development fund, bids were solicited that required a minimum of 30 percent energy savings. Several competitive bids were received, an award was made, and the project has been in operation since 2008 (Singh and others 2010).

Other municipal services: There are other opportunities to realize energy savings through municipal services, such as solid waste (waste recycling, methane recovery in landfi lls for power generation, and so on) and transportation (alternative fuel vehicles, maintenance of the public transit bus fl eet, establishment of rapid transit systems and congestion tolls, for example). An especially important aim in cold climates is to improve the effi ciency of district heating systems (box 3.8).

Beyond the public sector: Focusing on the built environment

As enforcers of national, regional, and local regulations, city governments substantially infl u-

Table 3.14 A Comparative Economic Analysis of Selected Streetlighting Systems

MERCURY COBRAHEAD, METAL HALIDE COBRAHEAD, HIGH PRESSURE SODIUM

COMPARED ELEMENT CONVENTIONAL ENERGY-EFFICIENT CUTOFF, ENERGY-EFFICIENT

Lamp type 400-watt mercury vapor 250-watt metal halide 250-watt high-pressure sodium Number of luminaries 12 12 11a

Installed cost, US$ 36,672 36,240 35,618 Annual energy cost, US$ 2,391 1,551 1,419 Annual operating cost, US$b 2,536 1,677 1,601 Total annualized cost, US$c 6,271 5,368 5,229

Source: NYSERDA (2002). a. Assumes a 10 percent reduction in the number of poles needed because of the higher luminous effi cacy of high-pressure sodium. b. Includes energy and maintenance costs. c. Includes initial capital investment, energy, and maintenance costs annualized over 20 years.