SAMPE Journal - July/August 2013 - (Page 48)

PersPectives Steven Rodgers SAMPE Past President and Consultant, EmergenTek LLC Steven.R@EmergenTek.com Li-Ions and NiCads and NiMHs! OH My! “I bought some batteries, but they weren't included” – Comedian Steven Wright It would be difficult to find somebody in our industry that has not read the headlines. The headlines involved a major aerospace company and a bold new commercial airliner. This aircraft was notorious in our industry because of a major commitment to extensive use of lightweight composites to gain economic advantage. Much has been reported about the airframe, the wings, lightning strike strategies, the new manufacturing requirements and a host of other connections to the composite structure. Somewhere in the reporting, a significant part of the story was lost on most of the public, including many in our industry. Traditionally commercial aircraft incorporated air-bleed systems and hydraulic systems to manage many of the onboard systems, from cabin make-up air to retracting the landing gear. The quiet revolution for this aircraft was the replacement of the air-bleed and hydraulic systems with electrical systems. This meant that each aircraft must be capable of generating as much as 1.5 MW of electricity, enough to power 400 typical American family homes. In fact, when I first learned of this in 2008, there were more than 900 of these aircraft presold. With the help of Google I discovered that if all of these aircraft were flying at the same time that they would generate from 7% to 8% of all the energy generated by wind energy in the United States in 2008 and they would do so by burning kerosene. But I digress. With such a large commitment to electrical systems came the necessity of backup energy storage systems, and to the surprise of many people this is where the aircraft received its most public challenge. The energy storage strategy was a common one using Li-Ion batteries. These are commonly used in laptop computers, cordless tools, hybrid and electric vehicles and cell phones. But in the final analysis, it was not the batteries themselves that were the problem, but rather the tendency for thermal runaway. Elon Musk is the founder of SpaceX and co-founder of PayPal and Tesla Motors. Tesla Motors has successfully employed Li-Ion batteries in all of their Electric Vehicles (EVs). The reason for their success is that Tesla took a different approach to thermal management of the batteries. This difference in battery thermal management also constitutes a departure in philosophy between Tesla Motors and rival EV manufacturer Fisker Automotive. In 2012 Fiskar drew some bad publicity when a battery fire burned an automobile and a garage to the ground. Shortly after that there was a second fire. Is it possible that the difference in battery thermal management may have contributed in small part to the comparative success and failure of these two companies? More than anything, these experiences point up what was shared in this column in the January/February and March/April 20121 issues of this Journal: That one of the primary issues with which scientists and technologists will be involved in the coming decades will be issues of energy storage. Effective energy storage is currently one of the major challenges associated with renewable energy. When energy is supplied by an intermittent power source such as wind or air one must be prepared to compensate with excess capacity during the times when the wind is not blowing or the sun is not shining. It has been estimated that as the energy grid approaches 20% of its capacity supplied by an intermittent power source the grid begins to destabilize, leading to rolling brownouts and, ultimately, blackouts. Energy storage is clearly a major consideration with regard to renewable energy sources that are intermittent. Certainly energy storage is central to transportation issues. The storage of petroleum fuels is so commonplace that we seldom think of it in terms of strategic importance, but for that segment of the transportation market it is significant and well developed. But with each new energy strategy in transportation comes a new set of possibilities. Beyond the obvious examples associated with electric and hybrid vehicles as stated above, there are issues associated with lightweight storage of Hydrogen, Compressed Natural Gas (CNG) and Compressed Air. Limiting the discussion of effective energy storage to conventional batteries runs the risk of restricting our considerations to one narrow segment of energy storage to the point of missing other possibilities. In the March/April 2013 “Perspectives” column2 I talked about the strategy of using induction charging “on the fly” to reduce the size and weight of the batteries carried by EVs. In this strategy, induction-charging units are built into the roadbed allowing EVs to recharge their batteries while driving at freeway speeds. However, this pushes the energy storage issues from the EV back to the grid, where the storage strategy can be land-based but is still an issue. 48 SAMPE Journal, Volume 49, No. 4, July/August 2013

Table of Contents for the Digital Edition of SAMPE Journal - July/August 2013

SAMPE Journal - July/August 2013
Contents
President’s Message
Technical Director’s Corner
Corporate Partners
Welcome SAMPE’s Newest Members
SAMPE Proceedings
SAMPE Student Chapter Funding Awards 2012-2013
SAMPE Tech 2013|Wichita, KS
Europe News & Views
SAMPE Europe’s SETEC 13 Wuppertal, Germany
Tech Tidbits
The SAMPE Foundation
SAMPE Tech 2014|Call for Papers
SAMPE Journal Editorial Calender
SAMPE 2013 Long Beach-A Review
SAMPE 2013 Photo Gallery
Industry News
Perspectives
Advertiser’s Index
Resource Center
Membership Application
SAMPE Proceedings Order Form
Industry Events Calendar
Chapter Contacts

SAMPE Journal - July/August 2013