New technology for traveling with less energy

Better airplane performance came from jet engines with turbine blades that operate in a 1426/spl deg/C (2600/spl deg/F) inlet-gas temperature. An important by-product of this development is the aeroderivative gas turbine, which when installed in a combined-cycle power plant, converts natural-gas energy to electric power with 60-percent efficiency. Independent power producers are selling this power for 3 cents per kWh. Another new and pertinent development has been computer simulation which predicts the aerodynamic performance of a given design. The "Raven," a human-powered airplane with a 100-mile nonstop range, illustrates the usefulness of modeling. It uses a carbon-fiber reinforced structure. The resulting airplane, with a 35-meter (115-foot) wingspan, weighs only 34 kg (75 pounds). Ten years ago, the author calculated the cost of traveling 1609 km (1000 miles) in 12 different vehicles. The cost energy for this travel ranged from $127.40 to $3.29. Now a battery-powered electric bicycle offers the lowest energy cost for the trip-$2.12.