Obama Onsen, Japan – On the foothills of the Mt. Unzen Volcano, the Nagasaki Prefectural town of Obama Onsen, which literally means “Small Beach Hot Springs” in Japanese, is harnessing the power of the earth. In the town famous for its relaxing therapeutic spas and some of the hottest natural springs in Japan, the local people have come together to start their own renewable energy initiative.
After the March 11, 2011 Great East Japan Earthquake and nuclear meltdown at Fukushima, the Japanese public support for nuclear power has waned. Prior to the earthquake Japan received 30 percent of its power from nuclear reactors, but since then all reactors have been shut off with the exception of a recent restart at Sendai Nuclear Power Plant on the southern tip of Kyushu Island.
To supplement the loss of nuclear power, the use of oil, natural gas and solar has since increased to stabilize the energy supply. However, according to reports only 2 percent of Japan’s geothermal resources are used to generate electricity.
The people of Obama Onsen believe that there is another way to produce clean geothermal energy in a way that is rarely done in Japan. Prior to this new initiative, the hot springs in Obama Onsen were noted to waste 70 percent of their famously hot water. The Obama Onsen Energy Plant uses the excess heat from natural hot springs to generate electricity. The concept has the power plant run and funded entirely by collaborating with local people and a company, Koyo Denki Co.
How it Works
The energy plant uses 100℃ (boiling) spring water in a heat exchanger. The hot water evaporates the fluorine into steam that turns the turbine. Sea water is used to cool the vapor back into liquid for the binary process to begin again.
“However this process still leaves excess heat,” explained Akihiro Sando, an office worker at the plant and graduate student at Kyoto University,”but we can use that for fish farming, agriculture, or even a spa much like the Blue Lagoon in Iceland, which is heated by the Svartsengi Power Station.”Water is pumped directly from an underground hot spring and fed into the power plant which rests on the seaside of Obama Onsen.
The concept, while seemingly logical for the seismically active country, has an uphill battle before widespread adoption. Most of Japan’s geothermal reserves are located in national parks and nature reserves where construction is prohibited. Further, in terms of output, the energy is nowhere near as efficient as that of a nuclear reactor. One plant produces about 100kw, compared to a nuclear reactor that produces 1,000,000 kw. “Our concept is not to make one big power station, but to make small-distributed power stations. The power stations can be the size of a house, and 20 such stations could power the entire city of Obama,” said Sando.
Ari M. Beser is the grandson of Lt. Jacob Beser, the only U.S. serviceman aboard both bomb-carrying B-29s. He is traveling through Japan with the Fulbright-National Geographic Digital Storytelling Fellowship to report on the 70th anniversary of the atomic bombings of Hiroshima and Nagasaki and the fifth anniversary of the Great East Japan earthquake, tsunami, and nuclear meltdowns in Fukushima. Using photo essays, videos, and articles, Beser will give voice to people directly affected by nuclear technology today, as well as work with Japanese and Americans to encourage a message of reconciliation and nuclear disarmament. His new book, “The Nuclear Family,” focuses on the American and Japanese perspectives of the atomic bombings. Follow him on Twitter @Aribeser, and Instagram @AriBeser and @HibakushaTNF.