Photovoltaic Electricity Generation

Satellite measurements put the solar constant – radiation that reaches area perpendicular to the incoming rays at the top of the atmosphere (and that is actually not constant but varies with season and has negligible daily fluctuations) – at 1,366 W/m². If there were no atmosphere and if the Earth absorbed all incoming radiation then the average flux at the planet’s surface would be 341.5 W/m² (a quarter of the solar constant’s value, a sphere having four times the area of a circle with the same radius: 4?r…

[Editor note: The following post, “Cap-and-Trade: The Temple of Enron,” appeared one year ago in MasterResource.  It is being reprinted in conjunction with the release of the outlines of the Senate energy/climate proposal. Robert Bradley, formerly with Enron, further documents Enron’s cap-and-trade shenanigans in other MasterResource articles listed at the end of this post. Two press releases from the Competitive Enterprise Institute and the Institute for Energy Research on the Senate outline are reproduced as well.]

“Since 1976, Enron [and predecessor company] employees have been at the forefront of developing air credit trading policies for governments and businesses…. Enron today is the largest and most sophisticated air emissions credit and allowance trading organization in the United States. Since 1990, Enron has participated in over 80 SOx allowance transactions and has also been active in establishing policies for trading NOx in the United States and carbon [dioxide] world-wide.”

[Editor’s note: This is Part I of a five-part series by Vaclav Smil that provides an essential basis for the understanding of energy transitions and use. Dr. Smil is widely considered to be one of the world’s leading energy experts. His views deserve careful study and understanding as a basis for today’s contentious energy policy debates. Good intentions or simply desired ends must square with energy reality, the basis of Smil’s worldview.]

Energy transitions – be they the shifts from dominant resources to new modes of supply (from wood coal, from coal to hydrocarbons, from direct use of fuels to electricity), diffusion of new prime movers (from steam engines to steam turbines or to diesel engines), or new final energy converters (from incandescent to fluorescent lights) – are inherently protracted affairs that unfold across decades or generations.…

In the wake of the BP well blowout in the Gulf of Mexico and the attempted terrorist bombing of New York’s Times Square, the broadcast media have been full of the sackcloth and ashes crowd pronouncing once more the end of the hydrocarbon era and the vital need for the U.S. to “break our oil addiction” ASAP.

Their soundbites start with a half-truth and end with a fallacy.  We are told that “60 percent of U.S. energy supplies still come from oil and gas,” with the implication that (i) all of that is imported; and (ii) the pittance that we produce domestically all comes from offshore facilities.

 It is true that 60 percent (actually 62.5%) of our energy comes from oil and gas.  But the portion that comes from natural gas, about 24% of total U.S.…