Carbon fiber composite autoparts can be 50% lighter than steel and 30% lighter than aluminum. Industrial-grade carbon fibers suitable for use in cars cost close to $30 per kg, Roberts says. High-end vehicle builders can afford expensive carbon fiber parts. “But how many people will really spend an extra $5,000 to $6,000 beyond the usual cost for a small car to own an electric car with a carbon composite body?” he asks.
In 2013, BMW plans to launch two mass-produced vehicles with carbon fiber composite passenger cages: the battery-powered i3, formerly known as the Megacity, and the hybrid i8, which can run on batteries or an internal combustion engine. Two years ago, the carmaker formed a joint venture with carbon fiber maker SGL Carbon to make carbon fiber parts for the i3 series.
Electrifying The BMW i8 (left), a hybrid electric vehicle, and the i3, a plug-in electric, are set to debut in 2013.
Teijin projects that, with the global push to reduce CO2 emissions, the market for carbon-fibre-based vehicles will grow to around 4 million per year by 2020 [About 5-7% of all new cars]. If 200 kg of carbon fiber were used in each car then that would mean 800,000 tons of carbon fiber for cars by 2020. This would mean total carbon fiber production would be about 6 times higher than others like consultant Roberts project.
For every 10% weight reduction, the vehicle’s fuel consumption reduces by 6 to 7%. A car that weighs half as much would get about 40% better fuel consumption. A car that weighs 30% as much would get about 20% better fuel consumption.
Consultant Roberts says automotive applications are now just a tiny portion of the industrial carbon fiber market, which he sets at roughly 16,000 metric tons per year. Total global fiber demand, including aerospace and sporting goods, is about 40,000 tons. He projects that overall fiber demand will nearly quadruple by 2020. Industrial fiber demand is likely to increase almost sevenfold to 105,000 tons.
However, much of the industrial growth, Roberts predicts, won’t come from the auto industry. More promising markets, he says, include turbine blades for offshore wind energy projects, compressed natural gas storage tanks, and components for deep-sea oil-drilling platforms.
One of the longer-running efforts to lower the cost of carbon fiber has been going on at DOE’s Oak Ridge National Laborataory since the late 1990s. The lab has explored both the development of alternative fiber precursors and ways to lower fiber processing and carbonization costs. Achieving those goals would contribute to U.S. energy independence through such things as lighter-weight vehicles and high-performance windmill blades.
A lignin-based carbon fiber costing 30% less than PAN-based fiber would be an enormous breakthrough enabling even the most cost-conscious carmakers to use composite