Commentary
“Environmentally Friendly” is a warm and fuzzy phrase, but as mankind strives to limit carbon-dioxide emissions, defining it is becoming diabolically complex.
Electric cars are not zero-emission vehicles if their batteries are recharged with power from coal-fired power plants.
Hydroelectric power does not produce CO2 emissions, but giant dams and reservoirs nevertheless have a negative impact on ecosystems and local human populations.
And lightweight vehicles offering high mileage are not so eco-friendly if the processes used to manufacture them are dirty and energy intensive.
These contradictions are coming to a boil now as auto makers struggle to meet climate-change mandates around the globe. The big challenge is not just meeting the letter of the law, but also making truly sustainable products.
This quandary is raising the profile of a methodology known as lifecycle analysis.
LCA looks at the total greenhouse-gas emissions from all phases of a vehicle’s life, from its manufacture to end-of-life disposal. It has been around for decades, but LCA is gaining momentum now as a growing number of industries race to become greener.
The steel industry is championing LCA as a means of protecting its turf from lighter alternative materials as auto makers seek to shed pounds.
Steel currently accounts for about 65% of the typical light vehicle by weight. Analysts say it will remain the dominant automotive material for at least the next six or seven years.
That’s because auto makers will realize most of their near-term weight reductions simply by replacing conventional steel with lighter, stronger advanced high-strength alloys.
Even the Chevy Volt extended-range electric car will have a steel body when it debuts later this year.
But after 2017, steel’s future is less certain. As the importance of reducing mass grows with tightening emissions rules, lightweight alternatives such as aluminum, magnesium and even ultra-light carbon fiber are gaining ground in future product plans.
The BMW Megacity electric car is scheduled to debut in 2013 with a carbon-fiber body. Other European and Asian auto makers also are experimenting with new manufacturing and fabricating techniques to lower the material’s high cost.
That leads the steel industry to tout its FutureSteelVehicle for electrified vehicles in addition to the LCA benefits of steel. Made from advanced high-strength steel alloys, the FSV’s optimized structure is 35% lighter than a conventional steel body.
Comparable aluminum and carbon-fiber structures can be lighter, but much more CO2 is created during their manufacture than with steel.
Lawrence Kavanagh, president of the Steel Market Development Institute, says when the total vehicle lifecycle is considered, steel is the most environmentally effective choice for auto makers because in addition to the relative light weight of high-strength alloys, steel is 100% recyclable at the end of its life and less greenhouse gases are created during its manufacture than competing materials.
In fact, a study by Toyota showed carbon-fiber production creates more CO2 per pound than any other automotive material.
But steel’s competitors also understand the growing importance of LCA. The carbon fiber for the Megacity vehicle will be manufactured in a new facility in Moses Lake, WA, using carbon-free hydroelectric power.
