According to experts, an optimal measure to save power is to use sodium and compact lights instead of high-voltage mercury lights and incandescent lights for public lighting and a control system that gradually reduces luminous intensity in low-load hours. Especially, double-load bulbs can adjust electricity consumption from 250W down to 150W. While in rush hours, bulbs operate with 100% of capacity, in low-load hours, they can self-adjust to 150W. With the ability of self-adjustment, this type of bulbs saves 25-30% of energy. Using double-load bulbs that can self-adjust from 150W down to 100W along with well-reflected lamp-lets will save 59.4% of energy consuming cost.
Unfortunately, this type of lights is expensive. Anyway, the money saved by using them is more than the replacement cost. Ho Chi Minh City is currently investing VND 140 billion to install a system of controlling and monitoring power network with France’s MODUNLUXICDM technology. By the end of 2007, the system will have operated and monitored 12,000 lamp sets, saving VND 10 billion annually. And Hanoi is carrying out a campaign of replacing low-quality and expired light bulbs with new higher-quality ones. Initially, replacing high-voltage mercury lamps with sodium ones of which lighting efficiency is doubled for electricity saving is concentrated on. 250 W bulbs are replaced with 150 W ones in streets requiring lower luminosity. Using Dimm ballasts also minimizes consuming capacity, saves energy and enhances quality of lighting. Traffic lines with sub-wires will use 150-400W sodium bulbs. Improving lighting system at some public gardens is to upgrade its quality and save energy. Replacing incandescent lamps of decoration system with Led lamps with higher luminous efficiency and service life so as to save energy and improve the system’s appearance and durability.
For advertising lights, it’s important to have appropriate design solution by selecting types of lights conforming to using purposes and efficient in lighting. It depends on advertising aims, environmental conditions and power supply capability. As assumed by experts, using high-voltage lamps with high density is either redundant or low in efficiency. Instead, it’s advisable to use compact fluorescent lamps which save 80% of energy and 6 times more durable than incandescent ones, or to use a wide range of fluorescent lamps with high lighting efficiency. Examples are Maxx 801 fluorescent lamps which apply Ticolor Phosphor technology, 20% higher in lighting efficiency than normal ones, and T8/36W small-tube fluorescent lamps saving 10% of energy, etc. Generally, power-saving bulbs have colors suitable with people’s eyesight.
From Vietnam’s Technology, Vol.47