Recycled Cooking Oil Fuels LED Cherry Blossoms in Energy-Conscious Japan

東京、けやき坂のイルミネーション。画像:FlickrユーザーのDick Thomas Johnsonより。CC-BY-2.0.

Illumination in Keyakizaka, Tokyo. Photo from Flickr user Dick Thomas Johnson. CC-BY-2.0

An innovative approach to recycling and alternative power generation is allowing the cherry trees along Tokyo's Meguro River to “bloom” in winter.

This past winter, waste cooking oil was gathered from local households and restaurants to light up LED lights the color of cherry blossoms for the 2014 Everyone's Meguro River Illumination. The cooking oil was then recycled and converted into biodiesel fuel that in turn was used to generate electricity.

Everyone's Meguro River Illumination: A winter event held around Gotanda (walkways alongside the Meguro River in Gotanda, Tokyo), decorating cherry trees along the river with unique cherry blossom color (pale pink) LEDs.

The waste cooking oil also fueled the trucks that were used to collect the waste oil itself.

Recently in Japan, biodiesel fuel — fuel made from recycled cooking oils and fats — has gained attention thanks to increased numbers of cars that can use it. The technology is now more practical, and is a great way for common people to reduce their environmental impact.

According to a report from Japan's Ministry of the Environment, at least 450,000 tons of domestic waste cooking oil is collected each year across Japan:


In Japan, 2.3 million tons of cooking oil is consumed each year. About 450,000 tons of this used oil is collected as waste for recycling or disposal. It's relatively easy and efficient to collect waste cooking oil from food processors and restaurants. This oil can then be effectively reused as feed stock for fuel, fertilizer, soap, raw material for ink and boiler fuel. On the other hand, the collection rate from households is low because most of the waste cooking oil is disposed by directly disposing of down the drain, by incinerating it with the rest of the trash, or by sending it to the landfill. (source)

Another significant advantage of burning biodiesel is that the fuel emits no sulfur oxide, itself a serious cause of air pollution.

There are even slogans for biodiesel: “eco-friendly clean energy for next generation”; “local energy generation for local consumption”; and “100 percent off-grid generation.”

Everyone's Meguro River Illumination: Winter cherry blossoms are in bloom beside the Meguro River.

Winter magic or waste of electricity?

Cooking oil-fueled cherry blossoms aren't the only lights brightening Tokyo in winter. Every year from late autumn to the Christmas holiday season the city's streets are lit up by colorful illuminations at night. After Christmas events and autumn leaves, night-time illumination of city streets is something Japanese people look forward to during the darkest time of the year.

Last Saturday, I went to Kiyomizu-dera (temple in eastern Kyoto City) for the special night viewing! It was so beautiful! The special opening period will end this weekend.  

However there are some who think night illumination is a bit waste of electricity. 

Since the “triple disaster” triggered by the Tohoku earthquake and subsequent tsunami on March 11, 2011, national sentiment in opposition to nuclear power and in favor of moving towards alternate forms of energy has only increased.

One reason for this change in public opinion was that the 3/11 triple disaster included a massive and ongoing nuclear accident at a large nuclear power complex in Fukushima.

Following the Fukushima disaster, all of Japan's nuclear power plants were shut down out of fears that another major earthquake would trigger more nuclear accidents. The shutdown posed tremendous challenges for Japanese society: until March 2011 the plants had provided more than half the nation's power supply, 

The result of the earthquake, tsunami, nuclear accident and nationwide nuclear power plant shutdown was immediate power shortages, followed by the launch of nationwide power saving campaign that extended to schools and office buildings.

Rolling blackouts (planned blackouts) were implemented to reduce power consumption and make sure blackouts were evenly distributed. Japanese society also worked to minimize the use of air conditioners and heaters, encouraging people to use stairs instead of elevators and dimming store interior lighting.

Many “We are saving energy!” (節電, setsuden) signs appeared on the walls and windows of public spaces.

Nice power saving! RT @TokyoAcademy: “The exam prep space is saving energy.” [Image: “Fans for use inside (un-air conditioned) building]

As time has passed since the disaster, many special events that had been given up before have resumed, such the nighttime illumination of cities. 

At the same time a considerable number of people have voiced the opinion that Japan should give higher priority to securing stable power for daily life necessities rather than special events.

Is making sure there is enough electricity for nighttime illumination something we should be focusing on? If we can afford illumination we should also be able to afford stopping conserving power in our daily lives.

Another Twitter user pointed out the paradox between the societal movement to reduce electricity consumption while at the same time trying to attract visitors with nighttime illumination.

I really can't  forgive them when they say, “We pay for the electricity by ourselves. No problem!!” RT @uk_dfz: Three years have passed since the disaster. I can see illuminations wherever I go. No nuclear power plants are operating at the moment, right? Planned blackout? Saving power? What was the point?

Japan, like many other countries, has always struggled with limited natural resources and securing new energy sources. There is some awareness of alternate energy sources, but the “clean energy” movement is still in its infancy. Perhaps the biodiesel-fueled cherry blossoms lights on the Meguro River provide a clue about how to deal with the dilemma that exists between the anti-illumination criticism and the desire for pleasant winter lights at night.

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