In an era of polarized politics, the stuff of government programs rarely escapes debate. And often, the debate is nothing short of fierce.

It comes as something of a relief, therefore, to read a measured discussion—without exaggerated claims and counterclaims—on the role of renewable energy from as ready a source as The Wall Street Journal. Need some perspective on the size of renew-ables? Where are they making inroads, and where are they falling short? And what about the costs? What are the “myths” that need to be dispelled?

The scale of US power generation—about 20% of world generating capacity—can at times overshadow the contribution of renewables. For example, wind power's generating capacity, at 60-plus gigawatts, may constitute only about 5% of US generating capacity, but this is more than the entire electricity generation capacity of Australia or Saudi Arabia, according to the WSJ report.

The question of wind power variability—getting power in the right amounts and at the right times—is being answered as wind farms become more widespread, the network of transmission lines increases, and integrating wind power into the electric system becomes easier.

With transmission constraints, up to 17% of wind power in Texas had to be “dumped” four years ago, but such curtailments fell to below 4% in 2012, and now wind accounts for 10% of electricity generated in the largest US power market.

Surprisingly, the wind sector's contribution in terms of new additions to US electric generating capacity surpassed that of natural gas in 2012, according to the WSJ report.

However, the report cites what are nameplate capacity figures (13.14 gigawatts of additions for wind, 9.19 gigawatts for natural gas), without adjustment for a higher capacity utilization for natural gas. With wind farms typically running closer to one-third utilization, and gas-fired plants closer to two-thirds, the effective net additions would be more like 4.3 gigawatts of capacity and 6 gigawatts, respectively.

What about costs?

For wind and solar, costs are 8 cents and 13.3 cents per kilowatt hour, respectively, compared to costs of 3 cents per kilowatt hour for the existing coal fleet and 6.2 cents for new gas-fired plants. Costs are sourced from a recent paper by the Journal of Environmental Studies and Sciences, which additionally offers cost data factoring in “social cost of carbon,” such as the effects of COand SO.

Adding in these, the study shows the “real cost” of gas-fired generation creeping up by 1.3 cents to 7.5 cents per kilowatt hour, while, for the existing coal fleet, costs rise by 6 cents to 9 cents.

Abundant supplies of cheap natural gas obviously make it harder for renewables to compete without federal subsidies. Producers in the wind sector, for example, enjoy a 2.2 cent tax credit per kilowatt hour of electricity they generate. But, setting aside the subsidy issue, would it be technically possible for renewables to displace much of fossil fuel use?

Research by the National Renewable Energy Laboratory found that, technically, the US could get 80% of its electricity from renewables by 2050—but at what level of social cost?

In addition to a steep ramp to 40 gigawatts of capacity additions each year, there is the issue of where to place all the wind, solar and hydroelectric facilities.

And the buildup would require a near duplication of the existing transmission network, raising questions as to where the new lines would run and who would pay for them.

As for job creation, there is clear disappointment in what the report says is the “myth” of renewable energy being able to offer “millions of green jobs.”

The WSJ describes as “expansive” the Bureau of Labor Statistics' count of 3.4 million green jobs in 2011, which includes, for example, some 166,000 bus driver jobs. More telling are the direct employment numbers, with the wind industry saying it employed 81,000 in 2012, down slightly from the 85,000 employed in 2008.

We know all too well that the natural gas market has been far from robust, but at least it offers a real marketplace in which a marker is laid down where supply and demand meet.

And if the health of the sector is reflected in its jobs, “by far,” the report concludes, “the biggest jobs story in the energy patch has come from the oil and gas boom.”

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