Water is the essence of life. Harnessing its power responsibly is the essence of innovation in hydropower turbine coatings.
By Randy B. Hecht
Picture the world as it was in 1868. That’s the year “Buffalo Bill” Cody began working as a scout for the U.S. Army. French astronomer Pierre-Jules-César Janssen discovered helium. Japan’s shogunate era came to a close.
How long after these events did the first home use lighting provided by hydroelectricity? If you answered “that same year,” give yourself a gold star. That’s right: 11 years before Thomas Edison introduced the world’s first incandescent light bulb, Cragside—the Northumberland home of Lord Armstrong—featured a single lamp powered by hydroelectricity.
Nearly 150 years later, renewables generate 23% of the world’s electricity supply—and hydropower accounts for more than 70% of the total. That means more than a billion people in 152 countries depend on this resource, the International Hydropower Association says. And the International Energy Agency projects that “emerging economies have the potential to double hydroelectric production by 2050, preventing up to 3 billion tons of CO2 annually.”
These increases in capacity coincide with a growing global market for energy that makes it necessary to sustain higher levels of hydropower output. The same market pressures are driving expansion into less accessible, more contaminated waterways that present higher levels of silt, sand, or gravel debris. These factors combine to present immediate or potential challenges to continuous operation of hydropower plants.
With demand surging, utilities must achieve higher levels of water pressure and velocity, which can put additional strain on turbines. In remote locations, a higher volume of particles in the water increases the risk of damage to or accelerated wear on turbine components. And sometimes, when one set of operating conditions presents certain problems, the opposite conditions just present different problems. For example, turbines that operate under higher water pressure and velocity suffer higher rates of erosion—but lower pressure results in greater wear from debris.
To minimize such risks, advanced coating materials and techniques must work in conditions that vary significantly from one hydropower site to the next. Customized coating materials and technologies make it possible to address each turbine’s unique requirements and each environment’s conditions. These coatings can extend the life of the turbine by three to five times the lifespan of uncoated components. They also allow hydroelectricity projects to maintain their power output and so to remain an effective renewable energy resource.
Coating systems and processes offer additional opportunities for customization. With names such as high velocity oxy-fuel, atmospheric plasma spray, and wire combustion spray, the systems can sound like science fiction. But their impact on turbines’ productive life is real.
Oerlikon Metco has been working with leading hydropower turbine manufacturers since decades and can perform its coating services at the company’s facilities or on the client’s premises. Its approach to partnering with manufacturers and operators helps to ensure optimal turbine – efficiency, and the breadth of its experience in the sector enables to recommend the best available coating option. As demand for renewable energy sources continues to grow, the company will build on this expertise by pursuing new advances in coating materials and application techniques.
Hydroelectricity has taken us a long way from that single lamp in the English countryside. Coating materials and technologies are key to ensuring that it takes us even further. Just as life depends on water, the future depends on innovations that power growth without depleting the earth.