This article was published in the July/August 2011 issue of LEDs Magazine.
View the Table of Contents and download the PDF file of the complete July/August 2011 issue.
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The Institute of Energy Economics, Japan (http://eneken.ieej.or.jp/en) recently published a report on the electricity-saving potential of LED lighting and concluded that if all lighting in Japan was switched to LEDs, the total potential savings would amount to 92.2 TWh/year. This figure is equivalent to 9% of Japan’s current total energy consumption. Fig. 1 (previous page) breaks down the savings by sector, and shows that the greatest potential exists in offices and commercial buildings.
| Total lamps (million) | Price per replacement LED lamp (¥) | Total initial cost (trillion ¥) | Payback period | Electricity savings (TWh/yr) | |
| Incandescent lamps | 340 | 2000-3000 | 0.8 | 1 yr 5 mo | 27.3 |
| Fluorescent lamps (straight tube) | 690 | 10,000-25,000* | 9.6 | 9 yr 11 mo | 49.7 |
| Fluorescent lamps (circular lamps) | 350 | 7000-15,000 | 3.5 | 18 yr 6 mo | 6.8 |
| HID lamps | 20 | 100,000* | 1.8 | 10 yr 11 mo | 8.4 |
| Total | 1600 | 15.7 | 92.2 |
Table 1. Cost and payback periods for replacing different lamp types with LED lamps. (*Includes possible infrastructure and labor costs required to make the changes.)
The report says that the switch would cost ¥15.7 trillion (around $197 billion), due to the current high cost of LED lamps compared with ¥100 for incandescent bulbs and ¥1000-1500 for CFLs. However the cost of replacing all the 340 million incandescent lamps would be ¥800 billion (around $9.9 billion). Such a move would lead to very significant savings of 27.3 TWh/year, as well as by far the shortest payback period.
The report also says that the cost of achieving the electricity savings (see Japan’s Eco-point Program transforms market for LED lamps) would be ¥1.3/kWh for incandescent lamps, based on a 40,000-hour lifetime. The figure is ¥14-17/kWh for replacing other technologies, and ¥9.2/kWh on average. In comparison, the cost of photovoltaic power generation is ¥40-50/kWh.
The report notes that households are highly sensitive to initial cost, so eco-point and other discounting measures are likely to be effective in promoting the spread of LED lamps. Meanwhile, businesses may require energy-conversation tax incentives and other subsidies to reduce the burden of up-front investment.
