The government Saturday started its first full-fledged investigation to assess the size of methane hydrate reserves in the Sea of Japan.
Japan succeeded in extracting natural gas from methane hydrate contained in geologic layers hundreds of meters below the Pacific seabed in March, but exploration under the Sea of Japan has lagged because the next-generation energy source is believed to exist in a form more difficult to exploit.
A survey ship equipped with a device to scan the geological formation of the Sea of Japan’s seafloor with sound waves left port from the city of Joetsu, Niigata Prefecture, on Saturday morning.
As part of the three-year survey, the vessel will also head to waters off the Noto Peninsula in Ishikawa Prefecture, according to the industry ministry’s Natural Resources and Energy Agency.
After narrowing down areas that appear to be promising, the government plans to conduct drilling for methane hydrate in fiscal 2014 from next April. It also intends to survey waters off Akita and Yamagata prefectures as well as areas around Hokkaido in fiscal 2014 and 2015, agency sources said.
Tasked with conducting the investigation are the National Institute of Advanced Industrial Science and Technology and Meiji University.
Methane hydrate, a substance with a sherbetlike consistency comprised of methane gas and water, is believed to exist in a wide area of the seabed surrounding the Japanese archipelago. According to one estimate, those deposits are sufficient to cover the nation’s consumption of natural gas for around 100 years, prompting speculation that they could be potentially invaluable for resource-poor Japan.
New geothermal plant?
Plans are afoot to build a 500-kw geothermal power plant on Okushiri Island off southwest Hokkaido that could start operations as early as fiscal 2016, sources in the central and local governments said.
If the project is realized, it would be the first geothermal plant on a remote Japanese island to capitalize on the feed-in tariff system for renewable energy introduced last July, according to the Natural Resources and Energy Agency.
The power station’s output would cover up to 25 percent of Okushiri’s consumption of power, which is currently generated by burning fuel oil. All of the electricity would all be purchased by Hokkaido Electric Power Co. at a fixed rate under the feed-in tariff program.
Improving the island’s energy self-sufficiency would help reduce fuel transportation and power generation costs, as well as the risk of fuel supply disruption from natural disasters, the sources said.
Under the plan, the plant would utilize hot steam from two wells in western Okushiri on which test drilling was conducted around 2008 by the semigovernmental New Energy and Industrial Technology Development Organization.
The use of existing wells would help keep down construction costs, while a local oil distributor would be involved in the power generation operations. The geothermal energy could even be used to power a hot spring facility, the sources said.
Although the energy development organization found the proposal unprofitable after drawing roughly 200-degree steam from the two wells at a depth of around 1,600 meters, the local government and business will conduct a new survey of the wells from September at the earliest, with support from the energy agency, according to the sources.
“It will lead not only to a stable supply of electricity but also town-building around the concept of a renewable energy island,” a municipal official said.
The only existing geothermal power plant in Japan has been operated by Tokyo Electric Power Co. on Hachijo Island, around 300 km south of Tokyo, since 1999. The Tokyo Metropolitan Government is planning to boost the ratio of renewable energy on Hachijo from 25 to 86 percent by building more power stations on the island.
Under the government’s feed-in tariff system, utilities are obliged to buy electricity generated via solar, wind, geothermal and other renewable energy sources at a fixed rate.