SpecialFocus
Solar Panel icon
ALTERNATIVE ENERGY
Sustainable Power with Performance Plastics
by Mike Oliveto, Mitsubishi Chemical Advanced Materials

As global organizations focus on improved product sustainability, reduced carbon footprint and increased use of renewable green energy, performance plastics are meeting the challenges that make these applications possible.

Engineers have been improving the energy generation costs of renewable technologies for decades and now offer biomass, geothermal, hydro, solar and wind-based energy that competes with the costs of fossil fuel sources. Geopolitical risk and global warming provide tail winds that are increasing the rate of adoption of these green energy technologies.

Of these technologies, hydro, wind and solar are the making the most impact, which is good news for the performance plastics industry. Both hydro and wind systems involve large parts and geometries that are impossible to injection mold. This article highlights demonstrated application successes in these energy segments and how you can participate.

Hydro energy is generated by the natural flow of water. Today, more than 16 percent of the world’s energy is generated by hydroelectric turbines, more than nuclear power. Hydro electric systems range from very large operations producing up to 10,000 megawatts to much smaller systems like those operating in the United States and Canada that range from 10-100 megawatts with more modern facilities producing more than 1,500 megawatts.

Historically these systems relied on greased bronze bushings and oil impregnated metallic bearings for oscillatory motion that are critical for valves to perform as needed. However, parts made from performance plastics, including thermoset-thermoset polyesters, have performed well for decades without the need for the added lubrication.

Wind energy, whether produced on- or off-shore, converts the air’s motion that results from differences in barometric pressure into mechanical energy via large, spinning blades that are part of a turbine, into electrical energy. Since wind speed and frequency depend greatly on location, wind energy sources are generally concentrated in areas where conditions are favorable for such investment.

Parts machined from self-lubricated nylons and polyesters and bearing grades of polyetheretherketone (PEEK) are used as anti-friction disks and pads within the nacelle yaw system, which allows the turbine to rotate itself into the wind to capture most of the wind energy. Similar pads in some designs also allow for adjustment within the nacelle pitching system and can even be used to enable the blades to rotate.

Large turbines (greater than 1 megawatt) mean higher stresses and larger parts, making machining from performance plastic shapes the most common way parts are manufactured. Parts such as these are highly engineered and designed to last a decade or more, meaning the best route into the supply chain is via the wind turbine OEM.

There are related opportunities around offshore wind turbines related to platform construction needs including sheaves, dock fendering systems, bend restrictor and nylon track plates used on trenchers laying the electrical cable lines that must run beneath the ocean floor.

Solar energy relies on technology that converts the sun’s energy into electricity through photovoltaic (PV) modules called cells. Since more energy reaches earth from the sun in one hour than can be used by the entire population of the world in one year, it is a very attractive energy source. There are no moving parts in a solar cell so opportunities for performance plastics can be harder to spot. Photovoltaics use semiconductors to convert radiation from the sun into electricity, meaning many solar applications are more easily classified as traditional semiconductor applications.

Solar cells are packaged as modules or panels that are combined into systems that may range from 10 mounted on a home roof to thousands of panels spread over hundreds of acres of flat land in the case of largest solar parks, farms or solar power plants. The largest of these may involve mirrors that concentrate the sun’s energy and even pivoting mechanisms that optimize the orientation of the mirrors and/or the panels as the sun’s angle changes over the course of the day. UV-resistant ultra-high molecular weight polyethylene (UHMW-PE) and internally lubricated nylons and polyesters have been machined into pivot bearings and bushings that maximize the efficiency of the systems. In this case, engineering firms designing these systems is the best entry point into the supply chain.

Reduced friction and the elimination of petroleum-based lubricants has been a hallmark of engineering plastics since nylon was first used as bearings and bushings more than 75 years ago. Today, next generation engineering and performance plastics contribute greatly to renewable energy technologies that are focused on planet Earth’s sustainability for future generations.