Some stakeholders continue to voice concerns about the performance of customer-sited photovoltaic (PV) systems, particularly because these systems typically receive financial support through ratepayer- or publicly-funded programs. Although much remains to be understood about the extent and...

Growth in renewable energy in the U.S. over the past decade has been propelled by a number of forces, including rising fossil fuel prices, environmental concerns, and policy support at the state and federal levels. In this article, we review and discuss what are arguably the two most important...

On August 8, 2005, the Energy Policy Act of 2005 (EPAct 2005) increased the Section 48 investment tax credit (ITC) for commercial photovoltaic (PV) systems from 10% to 30% of the project's 'tax credit basis' (i.e., the dollar amount to which the ITC applies), and also created in Section 25D of...

Renewables portfolio standards (RPS) have proliferated at the state level in the United States since the late 1990s. In combination with Federal tax incentives, state RPS requirements have emerged as one of the most important drivers of renewable energy capacity additions. The focus of most RPS...

In October 2008, the United States Congress extended both the residential and commercial solar investment tax credits (ITCs) for an unprecedented eight years, lifted the $2,000 cap on the residential credit, removed the prohibition on utility use of the commercial credit, and eliminated...

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...

The market for small wind systems in the United States, often defined as systems less than or equal to 100 kW that produce power on the customer side of the meter, is small but growing steadily. The installed capacity of domestic small wind systems in 2002 was reportedly 15-18 MW, though the...

The last two decades have seen a dramatic increase in the market share of independent, nonutility generators (NUGs) relative to traditional, utility-owned generation assets. Accordingly, the ''buy versus build'' decision facing utilities--i.e., whether a utility should sign a power purchase...

For better or worse, natural gas has become the fuel of choice for new power plants being built across the United States. According to the US Energy Information Administration (EIA), natural gas combined-cycle and combustion turbine power plants accounted for 96% of the total generating capacity...