Energy harvesting for automotive applications

Energy harvesters will help the automotive industry, but sometimes a battery remains more economical and practical. Examples follow.

06/06/2011


Energy harvesters do not necessarily make sense in all potential applications where a battery is replaced. Battery technology is continuously advancing and due to volumes achieved, the price points reached are at levels where harvesters cannot compete. That is not always the case though as, energy harvesting is well fitted to niche markets where battery replacement is not an option. Continuous operation of sensors or operation in inaccessible environments makes it cost intensive or even impossible to replace drained batteries.

The approach at IMEC is tackling the issue from the energy consumption side and the energy generation side. On the energy consumption side, IMEC is developing micro-modules that consume minimal amounts of energy. On the energy generation front, the approach is to develop micro-machined energy harvesters in combination with an energy storage component. Their autonomy will allow such wireless sensors to operate for an almost indefinite time without worries of battery charging or connection to a power grid.

A micro-sized piezoelectric transducer has so far shown the best result. It consists of a cantilever with one or several piezoelectric layers sandwiched between metallic electrodes forming a capacitor. At the tip of the cantilever, a seismic mass captures the vibrations of the machine to which the harvester is attached.

IMEC's new vibration harvester consists of a piezoelectric capacitor formed by a Pt electrode, an AIN piezoelectric layer (initial versions used PZT), and a top Al electrode.

The resulting harvester delivers energy that has constantly been improving in the past few years of development. At the current level of output power, IMEC's harvesters are already powerful enough and are harvesting energy in meaningful frequencies in order to drive simple wireless sensors that intermittently transfer sensor readings to a master, which is the case in tire pressure monitoring systems (TPMS) under development.

TPMSs are becoming standard on new vehicles. Specific issues that need to be dealt with in this type of application relate to the fact that a vibration harvester needs to be optimized to a vibration that is available at most speeds. Also, the modules must withstand shocks of several 100g which calls for extremely reliable sensors and components.

Thermoelectric energy harvesting has never received accolades for its efficiency (its theoretical maximum is over 20% although nothing more than a few percent has ever been achieved in practice). But in specific cases where adequately large temperature differentials are achieved, one can envisage adequate power outputs. An interesting example relevant to automobiles is harvesting waste heat at exhaust pipes, where temperatures can go up to a few hundred degrees.

Thus, recovery of waste heat using thermoelectric generators (TEGs) is another interesting application in the automotive environment, with work undertaken on this field by companies like Volkswagen and BMW. BMW developed a prototype vehicle with a TEG in 2007 with a power output of 200W and demonstrated a 300W TEG in 2009. This year, a 500W TEG will be shown in a BMW X6 prototype within a project funded by the US Department of Energy. BMW took the lead in developing TEGs for automotive application together with various development partners from industry and research (e.g. NASA-JPL) Also in 2009 Volkswagen developed a TEG that claimed a 300W output during driving on a motorway, leading to reduced mechanical load and fuel consumption reduced by 5%.

Researchers from the Berner Fachhochschule and EMPA, a Swiss research and services group, are developing a thermoelectric generator for vehicle waste heat recovery that is integrated in the muffler, rather than being installed as a separate TEG unit on the exhaust line.

This type of technology would also make sense in hybrid cars, that combine an internal combustion engine and an electric motor, but the lack of an internal combustion engine in fully electric vehicles makes this type of technology incompatible, the temperature differences in an EV are nowhere near as high as at the site of the exhaust.

For more information on the integration of energy harvesters in automobiles, don't miss the opportunity to attend Energy Harvesting Europe in Munich, Germany, June 21 and 22, 2011. A demonstration of the BMW TEG on an engine as well as presentations from IMEC, the Eindhoven University of Technology and progress with thermoelectrics and vibration harvesting from Marlow Industries and the Fraunhofer IKTS are just some of the highlights of the event.

www.idtechex.com/Munich IDTechEx



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Strategic outsourcing delivers efficiency; Sleeve bearing clearance; Causes of water hammer; Improve air quality; Maintenance safety; GAMS preview
World-class maintenance: The three keys to success - Deploy people, process and technology; 2016 Lubrication Guide; Why hydraulic systems get hot
Your leaks start here: Take a disciplined approach with your hydraulic system; U.S. presence at Hannover Messe a rousing success
Flexible offshore fire protection; Big Data's impact on operations; Bridging the skills gap; Identifying security risks
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Applying network redundancy; Overcoming loop tuning challenges; PID control and networks
Putting COPS into context; Designing medium-voltage electrical systems; Planning and designing resilient, efficient data centers; The nine steps of designing generator fuel systems
Package boilers; Natural gas infrared heating; Thermal treasure; Standby generation; Natural gas supports green efforts

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me