Auto and truck makers around the world face the daunting task of making their vehicles more fuel-efficient. Better fuel efficiency and emissions reduction are being mandated by regulatory authorities and are powerful market drivers for TEGs in this market segment. As a result, there has been a surge of interest in using waste heat recovery from thermoelectrics in transportation. Currently, heat from the exhaust system of a car or truck is useless as it is discharged into the environment. Thermoelectric Generators (TEGs) could convert some of this wasted heat into useful electricity. Integrating TEGs into cars improves gas mileage and reduces carbon dioxide and other greenhouse gas emissions. Consequently, nearly all automobile manufacturers are working to add TEGs into their cars within the next few years.
A typical automotive TEG has four main elements: a hot-side heat exchanger, a cold-side heat exchanger, thermoelectric materials, and a power conversion system. Automotive engineers face significant challenges in the application of TEG to cars. TE materials must provide high thermoelectric power conversion and be mechanically and thermally stable to ensure the TEG will last for the life of the car with little or no maintenance impact. In addition, the TEG must have excellent power density because the space in which the TEG system must be added is limited. Evident’s high-temperature nanostructured skutterudite and half-Heusler materials provide the needed characteristics.
In 2014 over 70 million passenger cars were built and sold worldwide, excluding light commercial vehicles and heavy trucks, buses, coaches and minibuses. Powerful regulatory drivers and the enormous size of this market make it an excellent opportunity for Evident’s TEG Technology Platform.
Industrial Waste Heat
Roughly a third of the energy consumed by the U.S. manufacturing industry is discharged as waste heat to the atmosphere or to cooling systems. These discharges are the result of process inefficiencies and the inability of manufacturing plants to utilize the excess energy. Industrial waste heat energy is estimated to exceed 10 quads/yr (1 quad = 1015 Btu), an amount equivalent to more than 1.72 billion barrels of oil. Industrial waste heat spans the entire temperature range but much of the heat loss is from 250°C – 700°C, perfect for Evident’s skutterudite and half-Heusler materials.
Key to the commercial development of TE materials for use under industrial conditions is that they must be thermally, structurally, and chemically stable. They must accommodate vibration and thermal cycling conditions without significant degradation. Evident’s TEG Technology Platform is especially well-suited to meet these demanding design requirements for waste heat in the medium to high temperature range.
The enormous size of the industrial market combined with high waste heat temperature streams for a diversity of processes, e.g., aluminum, glass, metal castings and steel – make this market an important opportunity for the application of Evident’s TEG Technology Platform.
Wearable technologies are becoming more and more in demand with estimates of a $5.8 billion global market in 2018, but also face considerable obstacles mostly around size and battery life. Evident’s proprietary room temperature nanostructured bulk bismuth telleruide (BiTe) material can radically improve these products. Using body heat, a BiTe TEG can help produce electricity needed to power the device all while being thin enough to ﬁt in the smallest applications.
TEGs will revolutionize many existing products by adding functionality that radically improves the value of the product. As an example, consider the application of TEGs in home boilers used for space heating. When an ordinary gas-fired boiler begins a heating cycle, an electrical starter switch allows the natural gas to begin to flow and ignites the gas. But electricity from an outside source is needed for the switch to operate. In the event of a power failure the boiler simply will not work. In colder climates where the loss of space heat poses serious consequences to life and property, this is a severe design limitation.
Using TEGs, the heating system can be made immune from power failures of any length. Studies have shown that grid power failures are increasing in both frequency and duration. Events like hurricanes, earthquakes, tsunamis and other disasters have heightened consumer awareness of risks and increased consumer demand for equipment and systems that provide better emergency preparedness. In this case TEGs open up a completely new class of product. Initially it will be considered a premium product but the self-powered functionality will likely become a standard feature on most natural gas-fired home heating systems over time.
The global market for gas-fired home heating boilers exceeds $11 billion a year. Evident’s TEG Technology Platform is ideally suited for this application and for countless others that have yet to be imagined.
Internal combustion engines are ubiquitous in marine applications providing needed thrust propel a vessel through water. Nuclear powered ships are popular as well, especially for submarines and other underwater vessels. Waste heat is a by-product of both internal combustion and nuclear power that is currently wasted. Marine applications are ideally suited for thermoelectric conversion of this wasted energy because of the natural temperature difference between the engine heat source and the ocean or lake water through which the vessel is traveling. The TEGs convert this temperature difference into electricity to power the hotel load, recharge batteries, or other applications. TEGs can increase the efficiency of the system and reduce the amount of waste heat.
Evident’s TEG technology is ideally suited for the temperature ranges that are typical for marine applications. High fuel costs for marine transportation is a real driver for this market and squeaking out more efficiency is of paramount importance. Evident’s TEG technology platform is poised to have a big impact for marine applications.
The commercial airline industry is pushing continued electriﬁcation to meet customer demand for in-seat entertainment, internet and charging capabilities. Temperature differences of hundreds of degrees are typical for aircraft traveling at cruising altitudes; jet engines produce hot exhaust that can be harvested with TEGs cooled by the ambient cold temperatures. The electricity produced is free in that it uses energy otherwise wasted and converts it into useful electricity.
Evident’s TEG technology can withstand the temperature extremes in this demanding application and give game-changing performance and flexibility to aircraft designers.
Another application ideal for Evident’s room temperature nanostructured bulk bismuth telleruide (BiTe) material are sensors – devices used to detect environmental characteristics. Sensors need to be powered in locations that can not be wired for electricity or can have a battery easily changed. Evident can make self powered sensors a reality by converting temperature differences to electricity used by the device itself. These maintenance free sensors can have applications in manufacturing and machinery, airplanes and aerospace, cars, medicine and robotics.