A subtle shift beneath the waves is unfolding, a new strategy quietly gaining traction as waves and tides are poised to anchor the clean energy transition. Rather than make loud headlines, the coastal energy revolution is positioning itself as the dependable backbone beneath the more celebrated renewables.
The world’s coastlines form an immense, untapped reservoir of predictable energy. Unlike solar and wind, subject to the fickle whims of weather, tidal and wave forces follow the ceaseless rhythm of the moon and sea, yielding a consistency highly prized in long‑term power planning. Yet this very predictability comes with high initial costs, daunting engineering challenges, and sensitive environmental considerations.
Advanced economies are now entering what feels like a quiet tipping point. In Britain, tidal‑stream technologies are edging closer to viability. Under long-term support mechanisms, over 120 megawatts is expected online before the end of the decade. A deeper proposition exists in tidal range schemes, barrages or lagoons, which could unlock as much as 20 gigawatts of capacity, potentially meeting over a tenth of national electricity needs by mid‑century.
Elsewhere, one operational facility has quietly been delivering over 250 megawatts to the grid for years, offering a compelling model of long‑term viability. Pilot projects on remote islands are testing innovative systems such as underwater kites controlled by advanced navigation systems, which could supply up to 40 percent of local demand within five years. These early deployments offer a glimpse into scalable blueprints that could be applied across thousands of global sites.
The broader wave and tidal energy market is expanding rapidly, with projections pointing to exponential growth in value and deployment. Collaboration between governments and private industry is now focused on solving the final barriers: advanced turbine design, resilient marine materials, dynamic anchoring systems, and hybrid integration with solar, wind, and storage. These efforts are beginning to converge, laying the groundwork for cost‑competitive, grid‑reliable marine power.
Environmental stewardship remains central. The challenge is to balance industrial deployment with ecological preservation. Studies increasingly suggest that, even at scale, the ecological footprint of marine energy installations is modest, particularly when compared to the broader consequences of climate change. In sensitive estuaries, planners are prioritising lagoon systems over traditional barrages, aiming to maximise capacity while protecting biodiversity.
For investors, three strategic insights stand out. First, coastal renewables provide valuable diversification. As energy systems shift toward higher shares of intermittent sources, technologies with predictable output will carry a premium. Second, the policy landscape is improving. Long-term contracting mechanisms, infrastructure incentives, and strategic government backing are aligning in key markets. Third, the economic profile is evolving. Though capital-intensive upfront, marine energy projects benefit from very long asset lives, low operational costs, and increasing standardisation.
The sector now sits on the cusp of transition, from niche experiments to integrated infrastructure. Early deployments are refining cost curves, validating business models, and reducing risk. Investors who took positions in offshore wind a decade ago may see familiar signals: technological inflection, policy alignment, and scale potential. While marine energy will not displace dominant renewables, it offers a distinctive and compelling complement, especially in geographies where tidal forces are a natural advantage.
Coastal energy harnesses the predictable movement of tides and waves to generate renewable power. Through submerged turbines, barrages, and innovative systems, it offers a consistent and increasingly viable source of clean electricity, well‑suited to long‑term infrastructure portfolios seeking dependable, differentiated exposure in the energy transition.
SAE Renewables Limited (LON:SAE) was founded in 2005 as a supplier of tidal stream turbines, SAE quickly grew to include development of tidal stream projects and is the majority owner of MeyGen, the world’s largest tidal stream energy project. a hub for clean energy storage, SAE exemplifies innovative reuse of industrial sites for modern needs.
