Tokyo Electric Power Company Holdings (TEPCO) has begun a seabed survey off the coast of Chiba Prefecture, Japan, to ascertain the bedrock structure of the seabed for a possible offshore wind farm.
A boring survey off the municipalities of Choshi, Asahi, Sosa, and Yokoshibahikari started this month and will last until the end of January 2019. The survey shall be conducted at two locations using self-elevating platforms. Core samples will undergo lab testing to determine their geological characteristics.
TEPCO will also conduct sonic prospecting in the same period. A sonic transmitter shall be lowered from a moving boat and used to map the seabed by measuring the differences in sonic waves reflected off the seabed.
On land, a boring survey will be conducted at four locations and the core samples will undergo lab testing to determine their geological characteristics. The results of the offshore and land boring surveys will be used in combination with the results of sonic prospecting conducted along lines joining the survey points to ascertain the ground structure of the entire area.
TEPCO began conducting offshore research off the coast of Choshi in August 2009 under a public initiative organized by the New Energy and Industrial Technology Development Organization (NEDO). In the years since, TEPCO has surveyed weather conditions, sea life and the potential environmental impact of offshore structures in the area.
Also, since January 2013, TEPCO and NEDO have been testing Japan’s first offshore wind power generation facility, a fixed-foundation offshore turbine with a rated power of 2.4MW, located 3.1km south of Choshi.
The test has provided TEPCO with experience in facility operation and maintenance as well as equipment safety and resistance to corrosion and other conditions. As a result, TEPCO has confirmed that the fairly shallow depths and high winds along the Chiba coast offer excellent conditions for an offshore wind farm.