Installations of PV systems have been expanding at a rapid pace in recent years. In the United States, the market for PV is driven by national, state, and local government incentives, including upfront cash rebates, production-based incentives, requirements that electricity suppliers purchase a...

Installations of solar photovoltaic (PV) systems have been growing at a rapid pace in recent years. In 2009, approximately 7,500 megawatts (MW) of PV were installed globally, up from approximately 6,000 MW in 2008, consisting primarily of grid-connected applications. With 335 MW of...

Throughout the United States, there is an accelerating abandonment of redundant and/or unprofitable light-density railroad lines. This abandonment can be economically harmful to both the shippers and the communities that were previously served. Although greater dependence upon truck...