In January 2001, early in George W. Bush's first administration, Vice President Dick Cheney convened a blue-ribbon energy task force to formulate a U.S. energy policy. Public-interest groups excluded from the process attacked the administration's closed-door approach. When the National Energy Policy appeared four months later, critics seized upon a perceived Big Oil and coal bias and decried a lack of emphasis on climate change.

The scenario has changed markedly in the past 13 years. Coal is still the leading electricity fuel source in the U.S., but the share dropped to 39% from 52% between 2001 and 2013, likely accelerated by the Obama administration's war on coal. Nuclear power use remains flat, dropping to 19% from 20%. Offshore, the 2011 Fukushima disaster in Japan dealt a body blow to the nuclear industry worldwide. In the U.S., work continues at two nuclear-plant sites, VC Summer in South Carolina and Plant Vogtle in Georgia. But both jobs have been marked by repeated costs escalations and schedule delays.

The combined 4,400-MW addition in capacity will help compensate for some 2,100 MW that disappeared from the nation's nuclear portfolio when Southern California Edison decided not to apply for relicensing of the San Onofre Nuclear Generation Station, which was shut down in 2012 after a small radioactive leak. The subsequent investigation revealed widespread excessive wear and tear on plant tubing. After Summer and Vogtle, prospects are minimal for the U.S., so nuclear engineering, manufacturing and construction companies are looking for work in China, India and other, more amenable places.

With electricity from oil and hydropower staying more or less constant from 2001 to 2013, the shortfall created by the cutback in coal sources is coming from natural gas and non-hydro renewables: wind and solar power. The Obama administration saw, in 2011, oil production increase to its highest level in a decade, while U.S. dependence on oil imports dropped to 45%, the lowest level in 20 years. Along with record domestic oil production, the country has experienced an unprecedented boom in natural-gas output. The Marcellus, Bakken, Eagle Ford, Permian and other basins have been operating at full throttle.

In 2013, natural gas had surpassed nuclear power as the second-leading U.S. electricity source, supplying 27% of the total, up from 16% in 2001. Advances in the technology and use of hydraulic fracturing have cracked open vast reservoirs of shale gas, even as the fracking debate continues. Opponents see the practice as a major threat to underground water supplies, while advocates see it as a means of recovering an abundant fuel source that burns cleaner than coal and emits a third of the CO of coal in electricity generation.

Pervasive Natural Gas

The rapid acceptance of natural gas is expanding well beyond powerplants. As a feedstock, it is a key component in the petrochemical, pharmaceutical and fertilizer sectors. Its influence extends well beyond U.S. shores. As the country moves from being a net importer of energy to a net exporter, more than two-dozen facilities have applied to the U.S. Dept. of Energy to export liquefied natural gas. There are a number of policy and regulatory hurdles to clear. Cheniere Energy is ahead of the pack, with its contractor Bechtel at work on the first new export terminal at Sabine Pass, Texas. How many others will follow is a matter of speculation, but even if a handful go ahead, the economic benefit will be worth billions of dollars.

Non-hydro renewables' overall slice of the energy-generation pie is still small, now at 6%, according to the U.S. Energy Information Administration. But wind and solar power's U.S. market share has tripled since 2001, and neither shows any sign of slowing down.

Congress has kept both technologies on a short leash, renewing tax credits for wind production and solar investment only on a year-by-year basis. Fossil fuels, which are protected by entrenched, powerful politicians from producing states, so far have been able to retain their preferred status through subsidies and favorable policies. But market forces and technological advances may ultimately carry the day. With large solar-thermal plants, such as Ivanpah, and solar photovoltaic plants, such as Agua Caliente, coming on line and three 700-MW-plus wind farms in the U.S., both wind and solar technologies are demonstrating they can serve large loads.