Solar-Powered Personal Rapid Transit (PRT): Electric Vehicles without batteries or congestion

摘要

Powering transportation with solar energy will require extremely efficient vehicles. Battery-powered vehicles pose difficult technical challenges that have not yet been proven in the marketplace. Personal Rapid Transit (PRT) provides a solution to transportation that 1) does not require batteries or liquid fuel and 2) solves the congestion problem with overhead guideways. We present a transportation solution that is based on a computerized driverless vehicle that runs on a solar-powered guideway suspended over existing highways. The potential market generated by this system is substantial. We estimate that 540,000 miles of guideway in the US would serve most urban centers and all major highways in rural areas. The goal is to provide a PRT station within 1/4 to 1/2 mile of every passenger. This would require 92.4 million kW of PV in order to provide 100% of the electricity to drive PRT. Nighttime use could be offset by daytime excess power provided to the grid or from wind and geothermal. The cost of PRT is significantly less than battery-powered electric vehicles and could be implemented in the timeframe required to manufacture 200m electric vehicles. Contracts for PRT PV would range in size from $20m for a small 10 miles loop to $20B for a large 1000 mile network assuming $3m per mile for the PV system. Today Sweden, South Korea and the United Kingdom have invested in PRT, with a sharply rising investment rate. Combined with solar, we see this field of technology as an unprecedented possibility in the transportation field for true sustainable travel. Several vendors have (1/4)-mile prototypes in progress and the first commercial implementation at Heathrow airport (without solar) is scheduled for Spring 2009. We expect larger implementations in 2010 as several cities are considering the technology. The solar community would benefit from early adoption in order to drive design decisions that incorporate PV. Our paper will detail the assumptions behind our estimates as well as the challenges facing adoption.