The odd looking goya has long been a popular ingredient in Japanese cuisine, but Tokyoites are now growing the courgette-shaped bitter melon for reasons of energy conservation, not food.
Skylark, a restaurant chain, is cultivating the goya to create “green curtains” outside the windows of several hundred of its Tokyo eateries. The plants, it says, should form a natural shade to cool the interiors, reducing its reliance on air conditioners.
The government has called on companies and households in eastern Japan to reduce electricity consumption by 15 per cent this summer, as Tokyo Electric Power struggles to contain the nuclear crisis at its Fukushima power plant. Kansai Electric is also urging customers in western Japan to cut their electricity consumption by the same amount amid concerns that its nuclear plants might face delays in receiving approval to restart.
In the area that Tepco serves, capacity could fall more than 10 per cent short of last year’s peak-time demand, the economy ministry estimates. The government is encouraging companies to shift work and production hours away from peak times to early morning and evenings, and reduce unnecessary use of lighting.
Some are taking more extreme steps in the hot muggy summer. Famista, a small website developer, has vowed to keep its air conditioners switched off and is paying employees Y2,000 ($25) a month to buy vest tops to wear.
Along with other companies, Skylark intends to set its air conditioners two degrees higher than normal – to 27C at the restaurant operator – this summer. The chain hopes the goya green curtains, combined with a special film it will apply to windows, will lower the temperature of a 330 square meter restaurant by two degrees.
Skylark favors goya because it is robust, has broad leaves, does not attract bugs, is easy to look after and fast growing. By the middle of the summer, each plant should be 2.5 meters high.
While the green curtains account for only a tiny portion of the 15 per cent electricity cuts the government is hoping for, they also serve another function, says Kazuyoshi Karasawa, the Skylark executive in charge of the energy-saving project: “We also hope it will heighten our staff’s awareness on the issue of energy conservation.”
Those who use green curtains, according to a 2009 survey carried out by Japan’s Green Curtain Support Group, used on average 21 per cent less electricity in August, compared with the year before.
The cooling effects of green curtains, which are probably better felt in smaller rooms than large restaurants, has also made them attractive to households.
May sales of goya green curtains on Rakuten, Japan’s largest online shopping mall, have risen nearly tenfold from last year.
Yuki Hashimoto, a Skylark customer in a Tokyo suburb, welcomed Skylark’s move: “It’s making use of nature and it’s not as if there’s a great view out there: it’s just a road.” And Tokyo could definitely do with more green.