High-pressure gas storage vessels represent one of the biggest and fastest-growing markets for advanced composites. In 2013, construction of pressure vessels of all types — metal, composite and metal/composite hybrids — represented more than $2 billion in global sales. That same year, pressure vessel manufacturers accounted for 6 to 7 percent of the estimated 65,000 metric tonnes (143.3 million lb) of global demand for carbon fibers. Although they are used in self-contained breathing apparatuses and provide oxygen and gas storage on aerospace vehicles, the primary end-markets for composite-reinforced pressure vessels are bulk transportation of compressed natural gas (CNG) products, and fuel storage in passenger cars, buses and trucks with powertrains dependent on CNG and hydrogen alternatives to gasoline and diesel.
Growth equation
Demand for alternative fuels is growing, in large part, because the extraction of natural gas from shale reserves has contributed to lower prices in North America and parts of Europe. In the North American market, for example, the cost of natural gas fuels currently runs about 40 percent less than diesel per diesel gallon equivalent. In addition, increasingly stringent emissions regulations, including the European Union’s (E.U.) Euro 6 Standard, which became effective earlier this year, are making diesel-powered buses and commercial vehicles more expensive for operators. Impending regulations are improving the marketability not only of CNG but also of hydrogen (H2) gas — after a period of relative dormancy — for fuel-cell powered vehicles.
In addition, the current availability of postrecession, low-interest loans has helped create a surge in demand for these alternative fuels, accompanied by strengthening and expansion of the pressure-vessel manufacturing base.
CNG vehicles growing
Five years ago, the number of natural gas-powered vehicles (NGVs) in operation around the world — cars, trucks, buses, and other industrial vehicles — totaled about 10 million. Aggregate data offered by nearly 90 countries indicates that during 2013, the global NGV population exceeded 20 million vehicles. In the next three years, it is anticipated that this number will approach 35 million vehicles. By 2023, NGVs could number more than 65 million (see Fig. 1, at left).
In 2013 alone, it is estimated that nearly 5.1 million NGVs were delivered to customers. By way of comparison, the general automotive industry manufactured about 87 million vehicles (of all types). Based on strong demand in Argentina, Brazil, China, India, Iran, Italy and Pakistan, NGV deliveries are expected to reach nearly 5.8 million vehicles in 2014 and could realistically grow to nearly 11 million per year by 2023. Vehicle types vary from country to country (see Fig. 2), but on the whole, about 94 percent of the total represents passenger vehicles; almost 4 percent are mass-transit buses and the remainder are medium- to heavy-duty trucks, forklifts and other industrial and commercial vehicles. Aggregately, over the 10-year forecast, there will be a market for 75 million NGVs. The vast majority of these, approximately 94 percent, are expected to be equipped with high-pressure (≥200 bar/≥2,900 psi) fuel storage systems. The balance will be equipped with liquefied natural gas systems, wherein the natural gas is cooled to cryogenic temperatures (-162°C/-260°F) for storage at relatively low pressure (4 to 5 psi/0.28 bar) in a liquid state.
Hydrogen fuels on the rise
Although CNG is commanding greater market share among global automotive OEMs, there has been a renewed push toward hydrogen fuel cell-powered electric vehicles (FCVs). Granted, past promises about the marketability of such systems were received with what was then well-deserved skepticism: If the predictions of policy makers and marketers had been accurate a decade ago, there would be more than 5 million FCVs on the road today (click on “The Markets: Fuel cells and batteries,” under "Editor's Picks," top right). In 2013, the actual number of transportation fuel cells delivered to customers declined to about 2,200 units, compared to approximately 2,700 units in 2012. Currently, the fielded fleet of FCVs around the globe stands at about 15,000, with a few hundred buses, trucks, and forklifts in commercial service. This situation, however, is beginning to change. Since 2007, 13 automotive OEMs have released FCV demonstrators and test fleets. These FCVs include the Chevrolet Equinox Fuel Cell, the Honda FCX Clarity, the Hyundai ix35 Fuel Cell, and the Mercedes-Benz B-Class F-Cell. Notably, in 2015, Toyota Motor Corp. (Aichi, Japan) expects to be the first company to offer a commercial FCV. Sales in Japan are expected to begin in April 2015 and open in Europe and the U.S. later in the year. Most importantly, Toyota won’t be alone. Hyundai is expected to follow suit, and Honda, Nissan, Ford, BMW and others plan to join them no later than 2017. These passenger-vehicle brands, combined with mass-transit buses and limited volumes of commercial trucks, are poised to make hydrogen-powered vehicles — finally — a reality.
Encouragingly, the number of refueling stations needed to support these vehicles is beginning to grow rapidly throughout Japan, Germany, the U.K. and other early adopters (the U.S. among them but, so far, only in California). Globally there are approximately 325 hydrogen refueling stations. Only 25 were added in 2013. During the next two years, however, Japan and California are planning to bring online a combined 100 new hydrogen refueling stations. Germany expects to add about 400 refueling stations by 2023. This analysis forecasts that at least 2,500 refueling stations will be operational globally by 2023. Using the CNG industry as a model, these hydrogen refueling stations have the potential to support between 10 million and 20 million vehicles.
