For Yumi Someya, Tokyo is an untapped oil field, full of potential to generate electricity.

The precious fuel, however, doesn’t exist underground. It’s a resource sitting in the kitchens of millions of Japanese homes — cooking oil.

Someya’s ultimate goal is to collect every last drop of used cooking oil, turn it into fuel and distribute the electricity generated from it to the households and businesses that provided it in the first place — a perfect cycle of energy.

“I want to tell consumers that there is an environment-friendly way to generate electricity that does not rely on nuclear power plants at all,” said Someya, 50.

Someya runs two organizations — U’s Corp., which turns used cooking oil into fuel, and Tokyo Yu Denryoku, which distributes electricity from two power plants that utilize the recycled fuel.

U’s collects around 60 tons of oil per month from 3,000 restaurants and 500 collection sites at pharmacies, gyms and other places throughout Tokyo and the surrounding area.

Someya has been in the business of recycling cooking oil for the past 27 years, but she became even more determined after the 2011 earthquake and tsunami crippled the Fukushima No. 1 nuclear power plant, causing three core meltdowns that contaminated the Tohoku region and depriving it of power.

Someya and her employees delivered food and supplies sent from Taiwan to Ishinomaki, Miyagi Prefecture. Each of the company’s cars bore a logo that said, “Fueled by used tempura oil.”

“People who saw them kept talking enthusiastically, saying Japan needs such renewable energy,” she said. “Even the local people who went through the worst and faced severe losses tried to encourage me to continue on with it.”

Someya first rose to fame in 2009 when she was listed as one of Time magazine’s Heroes of the Environment for her efforts to turn cooking oil into biodiesel fuel.

In the nine years since, Someya pioneered a way to turn cooking oil into fuel without changing it into biodiesel first. She also launched an electricity distribution company that provides power generated solely from used cooking oil in the same areas served by Tokyo Electric Power Company Holdings Inc., better known as Tepco.

“My oil-recycling company has evolved into an electricity distribution company,” Someya said.

The passion for recycling used oil runs in the family. Her grandfather started a resale business in a small factory in Tokyo’s Sumida Ward in 1949, when Japan was trying to rebuild from the devastation of World War II. Her father eventually became the president of the company — Someya Shoten.

Fast-forward to the late 1980s, when Someya, then 18 and fed up with the competitive academic life in Tokyo, left home with a backpack and began traveling around Asia.

Her travels led her to a near encounter with a deadly landslide along the border of Nepal and China that local people claimed was triggered by deforestation.

“I could have been killed if I had passed that section of road just five minutes earlier,” she said. “I was overwhelmed by the fact that human activities could cause such an environmental tragedy.”

She returned to Tokyo determined to start a business as a social entrepreneur, only to be shot down by everyone she talked to. It didn’t help that it was the late 1980s, when Japan was in the midst of the bubble economy and consumerism was rampant.

“Everyone talked to me as though I was an idiot because it was believed that environmental businesses would not benefit the Japanese economy,” said Someya.

Fed up, Someya retreated to Hong Kong, working at a travel agency to support backpackers like herself. However, during a later visit to her father’s oil recycling shop, she came to realize that “the solution to my quest was where I was born.”

Upon turning 23, Someya joined her father’s oil-recycling company, which two years later succeeded in turning used cooking oil into biodiesel. Marketed as Vegetable Biodiesel Fuel, Someya Shoten was the first in the world to commercialize such a fuel, which does not produce sulfur oxides and reduces black smoke emissions to about half that produced by conventional diesel.

Despite the success, Someya started her own company in 1997 with a focus on being environment-friendly after clashing with her father over business strategy. Just a few employees from her father’s company joined her.

However, for many of those who have long worked in the business as truck drivers, it was difficult to understand Someya’s mindset since she urged them to be not only drivers but salespeople. They thought the whole idea was a big hassle, so they left the company one by one.

It was also hard to motivate people to save their used oil for the company’s weekly collection. Unlike cans and bottles, Someya’s company charged restaurants and companies where collection sites were located ¥10,000 per year as a collection fee.

“For cans and glass bottles, people get paid for collecting and recycling them. But for the used oil, my company was charging clients. They did not really see the benefit,” said Someya.

After enduring the ups and downs, Someya’s company now operates two power plants that generate 100 percent of their electricity from used cooking oil.

Her latest mission is to create a society in Sumida Ward where fuel is recycled to generate electricity. Since her company provides electricity to people and businesses who provide used oil, she aims to have 20,000 ward residents participate in the program.

“Once I succeed in building a model at the ward level, it will be possible to apply it to any town, even in the countryside,” said Someya, adding that such a system would avoid having all profits just go to major utilities.

“‘Think globally and act locally’ as well as ‘produce and consume locally’ are my mottos,” Someya said. “And I’m still not giving up on becoming a used-oil magnate.”

“Generational Change” is a series of interviews profiling people in various fields who are taking a leading role in bringing about changes in society.