How reinvented turbines are boosting a cornerstone of the renewables revolution – and protecting fish

One energy source will play a vital role if the renewables revolution is to upend our energy mix for the better. Hydropower is the workhorse of the sector, generating more electricity worldwide than other renewables combined, according to the International Energy Agency (IEA).

While the combination of solar and wind was expected to overcome water power last year, hydro’s key role will continue for a decade or more, at least – but the 4,300TWh produced annually, says the IEA, can be supercharged by innovation.

Hydropower faces a conundrum: it’s widely recognised as a clean, reliable source, but there’s a belief that it has hit its peak from the design standards conceived of decades ago. The traditional system involves water being passed down a penstock so that gravity, combined with pressure, spins a wheel connected to a turbine to produce electricity, but other methods are now being deployed.

Enter the vortex

One of the most promising involves a vortex-based system that spins water into a whirlpool, developed in Australia, which can increase energy production by 10% or more. The method has been equated to a black hole by Marstecs, one of the companies behind the system. That 10% figure is based on retrofitting the new vortex system into pre-existing plants. Engineering advantages from a new plant could generate double or triple the amount of power compared with decades-old technology.

Beyond brute-force engineering, other decisions could eke out more efficiency from hydrogen. The AI revolution is sweeping all before it and the hydropower sector is no different, PV Magazine forecasts. It foresees a future where intelligent systems design enables turbines to be called on more accurately and quickly than the old way of working.

One of the biggest breakthroughs is in turbine reinvention. Conventional turbines were designed for efficiency, power output and longevity – but not ecological sustainability. New designs maintain and improve efficiency while reducing environmental footprint, particularly for fish populations. 

“For turbines that are better for fish survival to be adopted, they need to function identically to a conventionally designed turbine,” says Abe Schneider, co-founder at Natel Energy. “Prior efforts resulted in turbines with really low power density.” Natel’s design includes sleek blades that are 10 times thicker than conventional ones, preventing fish from being sliced on impact by the peripheral speed of turbines ranging from 20 to 30 metres per second. Blade edges are also angled to make it more likely that fish hit by them will survive. 

Such innovations are enabled by advances in computational power. High-performance computers allow engineers to model every aspect and design custom solutions. 

Doing the right thing

“Today it’s routine for us to take on a new project and create a completely new runner geometry for a specific hydropower station,” Schneider says. 

“It is a generational opportunity  to do the right thing, to modernise  our hydropower fleets, to be a continued, efficient, reliable, low-  or zero-carbon backbone of our  clean energy economy, while at  the same time making the right decision for the aquatic ecosystem.” 

IMechE's Hydropower Engineering 2025 event on 5 June will showcase the latest developments across the hydropower industry, covering regulatory updates, technical innovations, new opportunities and much more.