BP's Exit Threatens Japan's Offshore Wind Ambitions as Cost Headwinds Persist

BP's Planned Exit from Yamagata Offshore Wind Project

British oil major BP is considering an exit from a consortium developing an offshore wind farm off the coast of Yuza-machi in Yamagata Prefecture, adding to the growing list of developers retreating from Japan's once-vaunted offshore wind push. The consortium, which also includes Marubeni, Kansai Electric Power, Tokyo Gas and others, had won the rights to the project in December 2024 under a government auction system designed to accelerate offshore wind development.

The move comes a year after a Mitsubishi-led group walked away from three sites off Chiba and Akita prefectures, citing runaway construction costs driven by global inflation. That withdrawal shocked the industry because the projects were among the first awarded under the country's flagship public tender process. Now, BP's potential departure is fueling anxiety among other consortium members that more exits could follow.

Japan's Ministry of Economy, Trade and Industry (METI) is scrambling to halt the retreat. It plans to widen access to a long-term decarbonisation power auction that guarantees a minimum revenue stream for 20 years for clean-energy investors. Previously, only new applicants could participate; now, operators already selected for offshore wind areas will also be eligible. METI also intends to lift the per-project revenue guarantee cap, a move intended to improve project economics. However, one operator told Jiji that even with the enhanced support, "there is no margin for comfort" when it comes to profitability.

What a Withdrawal Would Mean for Japan's Renewable Goals

The Domino Risk After BP

BP's signal of intent to withdraw, first reported by Jiji, underscores the fragility of Japan's offshore wind pipeline. The Yuza-machi project was a major win for a consortium anchored by heavyweight Japanese trading houses and utilities. If an international player with deep pockets like BP cannot make the numbers work, it raises the spectre that other consortium partners—many of which are already squeezed by high interest rates and expensive supply chains—may reassess their participation. The memory of the Mitsubishi-led retreat is still fresh, and any additional exit would likely deepen investor scepticism toward Japan's renewable energy auctions.

Tokyo's Policy Response: A Lifeline or Too Little?

METI's decision to open the long-term decarbonisation auction to already-selected projects and to raise the revenue cap is an unusual step. Normally, auction winners are expected to bear construction and operating risk. The change effectively offers a kind of ex-post subsidy, acknowledging that the original bidding parameters are no longer viable. The policy tweak could improve the internal rate of return for the Yamagata project and others, but the on-the-record comment from an operator that margins remain razor-thin suggests the support may not fully bridge the gap. The core tension is that the auction framework was designed in a low-inflation environment, and inflationary pressures on steel, turbine components and shipping have since eroded project economics far beyond initial expectations.

Cost Inflation: Why Offshore Wind Is Struggling

Offshore wind is particularly exposed to global cost swings because it relies on massive, specialised turbines, installation vessels and heavy port infrastructure. The lead time between winning an auction and commissioning can span five years or more, during which input costs can move dramatically. In Japan, the situation is compounded by a lack of domestic turbine manufacturing scale, forcing developers to import equipment and cope with a weaker yen. Together, these factors have turned what should have been the “trump card” for Japan's renewable energy expansion—surrounded by sea—into a sector fighting for survival. METI's target of raising wind power's share of the electricity mix to 4-8% by fiscal 2040, up from 1.1% in fiscal 2023, now looks increasingly difficult to achieve without further intervention.

Next Steps for Consortiums and Tokyo

For consortium members in the Yamagata project:

• Marubeni, Kansai Electric, Tokyo Gas and other partners must urgently decide whether to continue without BP or seek a replacement investor, given that project viability hinges on the consortium’s combined balance sheet and expertise.
• The expanded long-term decarbonisation auction eligibility and higher revenue cap should be factored into revised financial models immediately, as they alter the floor on cash flows for two decades.

For other offshore wind developers and investors:

• Review existing auction contracts for escalation clauses or force majeure provisions that could be triggered by sustained cost increases, especially in light of the Mitsubishi precedent.
• Watch METI's upcoming detailed guidelines on the enhanced support scheme; the size of the revenue cap increase and the terms for already-selected projects will set the new baseline for industry returns.

For policymakers:

• The risk of a wider withdrawal cascade argues for streamlining Japan's port and grid infrastructure to reduce construction bottlenecks, which would directly address the non-inflation drivers of cost inflation.
• Consider whether the auction design needs a structural overhaul to incorporate inflation-indexed tariffs or other flexibility mechanisms, rather than relying on one-off support adjustments.