Just 1% of coastal waters could meet a third of global electricity needs New study

Just 1% of the world’s coastal waters could, in theory, produce enough offshore wind and solar energy to supply a third of the globe’s electricity by 2050.

That is the key finding of a new study conducted by scientists in Singapore and China, who systematically mapped the global potential for renewable energy at sea.

The researchers identified coastal regions with sufficient wind or sunlight, water depths shallower than 200 metres, relatively ice-free conditions, and within 200 kilometres of population centres.

They estimate that exploiting just 1% of these areas could generate over 6,000 terawatt hours (TWh) of offshore wind and 14,000 TWh of offshore solar energy annually. “Together that’s roughly one-third of the electricity the world is expected to use in 2050, while avoiding 9 billion tonnes of CO₂ annually,” the study notes.

Many European nations, including Denmark, Germany, Belgium, and the UK, already dedicate between 7% and 16% of their coastal waters to offshore wind farms.

Yet an article by The Conversation points out that the challenge lies not only in potential output but in speed and feasibility. Turning this theoretical potential into reality faces enormous technical, economic, and political barriers.

To meet climate targets, the article stresses that global electricity systems must be fully decarbonised within a few decades. Wind and solar have grown at record-breaking rates, yet onshore expansion is increasingly constrained by site scarcity and land-use conflicts.

Currently, offshore wind generates under 200 TWh per year—less than 1% of global electricity. By 2030, this may rise to 900 TWh. Achieving 6,000 TWh by 2050 would require annual installations seven times larger than last year’s rate, sustained for two decades.

Offshore solar faces an even steeper climb, as it remains largely experimental, producing negligible electricity today.

About 90% of existing offshore wind capacity is in shallow, sheltered waters of northwestern Europe and China, where turbines are fixed to the seabed. Most untapped potential, however, lies in deeper waters, requiring floating turbines—a technology currently representing just 0.3% of global offshore wind.

Floating wind faces major engineering challenges, including mooring, anchoring, undersea cabling, and maintenance in rougher seas. “It currently costs far more than fixed-bottom systems, and will need substantial subsidies for at least the next decade,” the study explains. Early successes and cost reductions will be essential for commercial viability.

The piece highlights, that offshore solar is further behind. The International Energy Agency ranks its technology readiness at only level three to five on an 11-point scale, barely beyond prototype stage. According to the study, offshore solar could become commercially viable in the Netherlands only around 2040–2050—well after the global power system ideally needs to be largely decarbonised.

The researchers conclude that offshore renewables will play a significant role in the energy transition. “Offshore wind, in particular, could become a major contributor by mid-century if its growth follows the same trajectory as onshore wind has since the early 2000s,” the article notes.

However, achieving this requires floating turbines to quickly become competitive and strong political commitment in the Americas, Australia, Russia, and other regions with large potential.

For now, the article concludes that the best strategy remains accelerating onshore wind and solar alongside proven offshore wind technologies, while preparing offshore solar and floating wind for the longer term.

By Nazrin Sadigova