Since 2016 the MeyGen array in Scotland has stood as the global benchmark for tidal stream deployment. But what began as a demonstration of concept is now evolving into a mature operation with commercial precision. Recent deployment of data‑driven cable monitoring has not only extended the reliability of its grid connection but also unlocked fresh cost efficiencies. UK‑based start‑up Indeximate has been retained for three more years after proving machine‑learning insights can detect weak spots in subsea cables before failure occurs. For investors, this shift means maintenance no longer remains a black box, but a predictive model that can protect cash flow and safeguard returns.
The value proposition is compelling. MeyGen’s system availability has held steady above 95 per cent while cumulative output has topped 75 GWh, and that’s just the current phase. In March alone, one 1.5 MW turbine exported a record 372 MWh, reaffirming that high‑reliability operations backed by robust monitoring can deliver near base‑load performance from tidal sources.
MeyGen is not a one‑off. A recent report from the University of Edinburgh, commissioned by Scottish Enterprise and Wave Energy Scotland, projects Scotland’s tidal stream potential rising to 4.3 GW by 2050, with 1.9 GW across the rest of the UK. If realisation aligns with ambition, the sector could inject nearly £4.5 billion in gross value‑added and support over 15,000 full‑time Scottish positions. Numerous contracts for difference already have been awarded to projects in Morlais and EMEC, and deployments beyond the test‑bed are moving into firm development. On a global scale, potential tidal‑stream capacity may reach over 300 GW by mid‑century, a market vista that invites attention from global energy portfolios.
From a financial viewpoint, this is not island‑scale tinkering anymore. It’s industrial‑scale deployment. The scaling pathways are clearly mapped: technology validation, supply‑chain development, consenting infrastructure, and investment readiness. What’s new today is how a digital layer, sensors, analytics, predictive tools, can significantly lower operational risk. For capital allocators focused on long‑duration, stable yield, even small reductions in maintenance outturns and unplanned outages materially enhance returns.
Meanwhile, across the equator, ocean currents are emerging as a parallel frontier. A fresh study harnessing 30 years of drifter data has spotlighted the Agulhas Current off South Africa, along with flow fields near Somalia, Kenya, Tanzania and Madagascar, as among the world’s densest and most stable marine currents. Power densities regularly exceed 2,500 W/m², up to two to three times more energetic than the best wind energy per square metre. That means smaller turbines, fewer moorings, and baseload-style consistency. For energy-hungry African coastal nations, this offers a pathway to clean, predictable power without the intermittency constraints of solar or wind.
Yet, realising this requires steps beyond measurement and modelling, deployment of subsea infrastructure, blade technologies suited to strong marine flows, grid integration, and regulatory clarity. Africa has partially built-in advantages: energy access challenges, coastal load centres, and potential for industrialisation. And the momentum is building, albeit quietly, among governments and development banks searching for climate‑resilient generation solutions.
What binds both fronts, tides and currents, is the emerging voice of investability. Tidal stream in Scotland is quietly crossing from ‘demonstration’ to ‘digitally assured commercial operation’. Ocean‑current power is moving from theory into the domain of asset portfolios. In both cases, the shift from engineering novelty to risk‑managed, tech‑enabled deployment is what exposes blue‑energy to real capital. The narratives in Scotland and on Africa’s coasts are complementary: stable, dense marine flows, increasingly turnkey monitoring, policy support, and disciplined scaling.
For portfolio strategists, it’s time to revisit marine renewables not as niche infrastructure, but as credible non-correlated contributors to clean energy yield. Marine power isn’t weather-dependent in the same way as solar and wind; its predictability offers distinct value. Moreover, early-stage digital operational capabilities—such as those being trialled at MeyGen, signal that future deployments could be procured with embedded monitoring, insurance optimisation, and low brown‑out risk.
Yet, hurdles remain. Capex per MW remains higher than for wind or solar. Supply chain still needs maturity. Regulatory timelines for marine build-out are long. And grid interconnection for isolated coastal zones adds complexity. But the trajectory is clear: each cable inspection averted, each megawatt deployed, and each study published nudges the sector closer to mainstream readiness.
From an investor lens, the emerging portfolio approach becomes: select projects with credible depth in monitoring, phased consenting, and underlying marine resource density. Those that bring digital asset health monitoring, much like smart insurance, stand to differentiate. That means more durable cashflows, lower risk premiums, and potential for structured linkages to yield , rare in nascent renewables.
Marine energy—harnessing predictable tides and continuous ocean currents, is emerging from demonstration into digital‑enhanced commercial readiness. Enhanced cable monitoring, phase‑wise grid integration, and clear economic modelling position Scotland and Africa as blue‑energy pioneers. What was once niche is now quietly approaching investable scale.
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.
