How material selection impacts clean energy production and effectiveness

Metals needed for clean energy

The focus of his talk was on the metallic materials needed to realize clean energy goals. For example, copper is a vital ingredient in any system involving electricity. With the electrification of cars and the environmental aspect of energy production being such an important part of climate change strategies, copper is particularly critical in the expansion of solar photovoltaic (PV), wind, bioenergy, electric vehicles (EVs) and battery storage, and in electricity transmission and distribution networks. Similarly, cobalt and lithium are key in EVs and batteries; nickel in geothermal, EVs, battery storage, and hydrogen; rare earth elements (REEs) in wind, EVs, and batteries; chromium mostly for stainless steel and low alloys used in concentrated solar power (CSP) and geothermal; zinc for the galvanized material especially needed in wind: Platinum Group Materials (PGMs) needed in hydrogen, particularly as catalysts; and aluminum for structural requirements in solar PV, CSP, electricity networks, EVs, and batteries.

Material and metal requirements vary widely depending on the type of clean energy production. In biofuels such as ethanol, for example, stainless steels such as 304L or 316L are widely used as are carbon steels for many components. As ethanol may contain small amounts of water, inorganic chlorides, and free acid, some corrosion is to be expected in carbon steel. When blended with gasoline, ethanol may lead to stress corrosion cracking (SCC) of carbon steel.

“SCC can be often observed in ethanol blending stations where carbon steel is used,” Coates explained. “This can impact tank bottoms, air eliminator vessels and piping.”

His advice: use stainless steel.

Similarly, ethanol and ethanol blends can corrode components made from aluminum, brass and martensitic stainless steels, causing problems for certain plastics. And with the ongoing effort to make ethanol out of waste agricultural products, the materials needed for one plant can be quite different from those needed for another type of plant waste. In some cases, high-alloyed stainless steels or C-type nickel alloys may be needed.

“More research is needed to determine what the best materials would be to make ethanol production more economical,” Coates said.

Materials for wind power

Wind production is currently the largest single source of renewable energy on the planet. Many different corrosion issues must be considered. Offshore wind farms suffer corrosion both below and above the water line.

The gear boxes used in wind turbines are of particular concern when it comes to corrosion. Typical gear material might be 18CrNiMo7-6 case-hardening, low-alloy steel in the quench and tempered condition.

“Gear boxes are often the first component to fail, especially if the materials are not of the highest quality,” Coates said.

Materials vary widely depending in wind turbine components. Towers are generally made from low-alloy high strength structural steel plates. The nacelle frame that houses the turbine is often made from ductile cast iron or welded plates and the hub from ductile cast iron. Shafts are typically made of high-strength alloy steels, and bearings from bearing allow steels.

Materials for solar and geothermal power

Coates went onto to discuss in detail the materials needed in solar PV and CSP, as well as geothermal plants:

“A wide variety and large quantities of materials are needed for clean energy production worldwide,” he said. “Materials will vary widely based on the energy source and the application. Innovation is needed to bring costs down further, including the use of new materials specially for those processes.”

Coates is a user of the Knovel material property search engine as well as the Knovel Corrosion database, which are designed to help engineers and researchers find materials and corrosion data hidden in handbooks, manuals and databases. There are thousands of materials and substances (metals, polymers, ceramics, chemicals, etc) and more than 100 properties (physical, thermodynamic, electrical, corrosion, toxicity) to search.

“The Knovel databases contain key information that gives clues to optimal and cost-effective material selection,” Coates said. “Knovel and other Elsevier sources help engineers find vital materials information and data quickly.”

These are just a few of the highlights of the Materials Needs for Clean Energy Production(opens in new tab/window) webinar.

Watch the recording(opens in new tab/window)