Additional information for the proposed methodology"Installation of LED street lighting technology with wireless network control"
1. Overview of the methodology applied

The proposed methodology involves introduction of high efficiency street light technology throughutilization of light-emitting diode (LED) lamps and wireless network control.

Compared to conventional lighting technology, such as mercury vapor, metal halide, andhigh-pressure sodium lamps commonly known as High-intensity discharge (HID) lamps, LED
lighting, semiconductor devices that produces visible light when an electrical current passes throughthem can generate light at much higher efficiency.

In addition, the wireless network technology enables controlling the volume of lighting inaccordance with various conditions, such as weather conditions and traffic volume, leading to further
increase in the efficiency of lighting that results in reduction of electricity consumption.

The image of the technology targeted by the methodology is demonstrated below.

Figure 1: Image of LED street lighting system with wireless network control
Source: Minebea Co., Ltd.
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2. Street lighting technologies available in Cambodia

Although the energy policy of the Government of Cambodia supports efficient use of energy, it is yetto adopt a program specifically targeting street lighting technology and based on the interview with
the Ministry of Environment of Cambodia, the vast majority of street lights utilize HID lamps
without wireless network.

3. Reference luminaire efficiency of street lights in Cambodia

Step 1: Determination of reference HID technology

Among various HID lighting technologies, High Pressure Sodium Lamps (HPS) and mercury lamps
are commonly used technologies for street lighting. As shown in Table 1, HPS lighting is to beconsidered as reference technology as it is the most energy efficient technology among the HIDtechnologies.

Table 1: Comparison of efficiencies of various HID lighting technologies for major arterial roads

Luminaire efficiency

Mercury Lamp

High Pressure Sodium Lamp

28～30(lm/W)

57～62(lm/W)

Source: Iwasaki Electric's Survey
Note: Surveyed lamps include those manufactured by major Japanese companies corresponding to2

The comparison of luminaire efficiency of various lighting technologies is demonstrated below.

Figure 2: Comparison of luminaire efficiency of HID lamps and LED lamps with wireless network
control for street lighting
Source: Representative data of Iwasaki Electric

Step 2: Determination of reference luminaire efficiency

Due to the unavailability of official or market information in Cambodia on HPS street lighting, theluminaire efficiencies of products by major street lighting technology providers in Japan have beensurveyed.

For the sake of conservativeness, the product type surveyed is based on the lighting usedon major arterial roads, which is higher in luminous flux and more energy efficient compared tolighting used on lower class roads.

3Table 2: List of luminaire efficiencies of products by major Japanese street lighting technology
providersLuminaire
ProductefficiencyRemarks(lm/W)
NH250F

57 Iwasaki Electric's product for non-Japanese market

NH250F

57 GS Yuasa's product for Japanese and non-Japanese market

NH220FLS

62 Iwasaki Electric's product for Japanese market

NH220FL/N

62 Panasonic's product for Japanese market

NH220F･L-N

62

Toshiba Lighting and Technology's product for Japanesemarket
Source: Survey by methodology proponents

Note: Luminaire efficiency = Rated lumens (lm) / Rated power consumption (W) x equipment loss(0.65) x ballast loss (0.85). Equipment loss is based on evaluation by Iwasaki electric and ballast
loss is assumed conservatively based on a Japan Industrial Standard (JIS C 8109)1

Based on the result of the representative luminaire efficiencies of HPS lighting as shown in Table 2,
the value of 62lm/W is selected on a conservative assumption in order to contribute to securing net
emission reduction.

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JIS C 8019 indicates that "high efficiency power factor" refers to values above 0.85.
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