Japan's Blue Bond breakthrough could unlock the next wave of marine renewables

In January 2026, Shimizu Corporation issued its first blue bond, a JPY 20.0 billion offering with a five-year tenor. The proceeds were earmarked to refinance the construction of “BLUE WIND,” a world-class self-elevating platform (SEP) vessel dedicated to offshore wind farm development. This issuance marked the first domestic blue bond to designate a SEP vessel as its use of proceeds.

Terms and Conditions of the Issuance 

                    
The Framework obtained a Second Opinion (*) from Rating and Investment Information, Inc. (R&I) 

(*) R&I Second Opinion：A Second Opinion is a document that describes the results of R&I's review as to whether the subject of assessment is aligned with specified principles and guidelines

The issuance of a blue bond by a major construction company in Japan, with proceeds allocated to offshore wind-related infrastructure, is groundbreaking in two key respects.

Firstly, the “blue bond” label—previously confined to niche areas such as sustainable fisheries and government-led marine conservation—is being extended to large-scale infrastructure projects led by major construction companies. 

Secondly, in Japan’s offshore wind sector, which has recently experienced a slowdown with some projects being withdrawn due to profitability challenges, the company has successfully secured substantial financing, effectively doubling the issuance size.
Self-elevating platform (SEP) vessels play a critical and irreplaceable role across the entire offshore wind project lifecycle—from early-stage geotechnical surveys to heavy-lift turbine installation and construction in challenging offshore conditions. Climate Bonds Initiative　strongly supports the development of SEP vessels for renewable energy infrastructure, as they are fundamental to scaling global offshore wind capacity.

Alignment with Climate Bonds Criteria 

According to the Climate Bonds Marine Renewable Criteria, assets dedicated to supporting offshore renewable energy infrastructure—such as Wind Turbine Installation Vessels (WTIVs) and jack-up rigs—are eligible for certification. “Dedicated” in this context means that the asset is used exclusively for the installation and operation of offshore wind energy facilities.

The construction of installation vessels, such as SEP vessels, satisfies the mitigation requirements of the Marine Renewable Criteria and is eligible for Certification under the Climate Bonds Standard. To achieve the globally recognised Climate Bonds Certification label, issuers must also demonstrate robust processes across the design, planning, and decommissioning phases, ensuring that construction and operation minimise environmental harm while enhancing the resilience of the marine environment.

“This is the first blue bond issued in Japan where the Use of Proceeds are allocated to the construction of SEP Vessels. We hope this transaction will catalyse further expansion of the blue bond market, mobilising capital at scale for offshore renewable energy and broader ocean-related sustainable investments.” - Yumiko Watanabe, Head of Japan Programme, Climate Bonds Initiative

”Shimizu Corporation has led decarbonization through continuous efforts in technological innovation and electricity generation using renewable energy. We evaluated that BLUE WIND is a blue project that contributes to marine environmental and marine ecosystem conservation, as it adapts and expands marine renewable energy.” - Nobuyuki Okumura, Head of Sustainable Finance Division, R&I