Coatings and composites help aging hydropower stations meet growing energy demands

(Pictured right: coatings and composites improve efficiency in hydropower stations - image courtesy of Protecmo)

Considering how global energy consumption is projected to increase significantly in the coming decades, it is absolutely critical that aging hydropower stations are modernised in a way to not only "sustain output", but to go beyond this. With polymeric repair composites and protective coatings, the efficiency of key hydropower equipment and facilities can be intrinsically enhanced and improved - thus enabling the industry to deliver greater output and meet growing energy demands.

Hydropower is the third largest source of power generation worldwide. Although it remains a cornerstone of the global energy mix, Fatih Birol, Executive Director at the International Energy Agency (IEA) highlights how: "[...] we must also remember that many hydropower plants in advanced economies are over 40 years old. Refurbishing them is vital to sustain output [...]".

It could be argued that, considering how the global demand for energy is expected to rise, it is imperative that refurbishment methods are deployed that go beyond the ability to "sustain output". Instead, strategies should be used that fundamentally improve and enhance output.

Indeed, the IEA anticipates "[...] continued increases in energy demand to 2050 [...]". In the two scenarios they outline, energy demand is expected to increase by a staggering amount - around 40% up to 2035. An increasing portion of this can be attributed to data centres, with data centre electricity consumption set to more than double to around 945 TWh by 2030.

Polymeric technology improves efficiency of hydropower stations

Amongst a number of strategies that support this expected rise in energy demand, asset owners are turning to polymeric protective coatings and repair composites. Not only can this technology repair damaged assets and protect them against future damage, but they can also intrinsically improve their efficiency too, as well as the overall efficiency of the hydropower station. As energy demand is expected to increase over the next few decades, refurbishing assets with efficiency-enhancing systems helps to support this growth.

By deploying these systems, hydropower operators are able to bypass the expensive and time- consuming process of asset replacement. As such, in addition to the significant financial savings these systems facilitate, they also simultaneously help hydro plants to minimise their climate impact. By repairing and improving damaged hydropower equipment and structures, asset owners can mitigate the hefty carbon footprint that can otherwise be incurred in the asset replacement process.

Engineered to withstand demanding conditions

Hydropower stations operate in some of the most demanding service conditions. High-velocity water flow, cavitation, continuous immersion, erosion, corrosion and mechanical wear all contribute to equipment deterioration and reduced efficiency. Industrial coatings and composite systems are engineered to repair, protect and improve assets in this challenging environment.

For example, the epoxy coating Belzona 1341 (Supermetalglide) can be used to improve the efficiency of different types of fluid handling equipment such as turbine runners, wicket gates and hydraulic valves.

This two-part epoxy coating improves efficiency by using hydrophobic technology to repel process fluids and reduce turbulent flow. Efficiency increases of up to 7% have been recorded on new equipment and up to 20% on refurbished equipment. When compared to polished stainless steel, it was found that Belzona 1341 (Supermetalglide) was 15 times smoother.

Failure of sealants between bolted flanges on switchgears in hydropower stations can result in SF6 gas leakage, reducing insulation performance and increasing environmental impact. Belzona SF6-FIX is designed to seal sulphur hexafluoride (SF6) leaks in switchgear systems. The solution can be applied online, without specialist tools, and can reduce leaks to undetectable levels.

Hydraulic ball valves play a critical role in flow control and are continuously exposed to erosion, abrasion and chemical attack. Surface degradation can reduce performance and operational reliability. Belzona 1000 Series paste-grade systems can be used to rebuild worn or damaged areas, restoring original dimensions while providing high mechanical strength and durability. Following restoration, a Belzona 1000 Series protective coating can be applied to provide long-term resistance to erosion-corrosion and flow-induced wear.

Pump bearing pedestals provide structural support and alignment. Damaged flange faces can lead to misalignment, vibration and premature equipment failure. Belzona 1000

Series repair composites can be used to rebuild flange faces and restore original geometry.

An industrial coating from the same range can then be applied to safeguard against erosion and corrosion, ensuring structural stability and extended service life.

Mitigate cost and carbon footprint of asset replacement

As global energy demand increases towards 2050, the challenge facing hydropower operators is not simply to preserve legacy assets, but to unlock greater performance from them.