In the Great Electricity-Generating Race it’s Coal by a Nose over Natural Gas with Solar Power Still in the Barn

Posted by PITHOCRATES - July 15th, 2012

Week in Review

Natural gas is running to catch up and pass coal in the great electricity-generating race.  While solar power is struggling to win a participation ribbon (see The Huge Shift in Our Energy System That’s Happening Right Now in 1 Chart by Alexis Madrigal posted 7/13/2012 on The Atlantic).

As long as Americans have made electricity, they’ve gotten more of it from coal than from any fuel. While petroleum and natural gas have played huge roles in our energy system, coal’s been responsible for more than 65 percent of the fossil-fuel electricity we’ve generated for most of the last 50 years. (And for big chunks of the 20th century, we made half of all the electricity in this country by burning coal.)

But natural gas is in the process of overtaking coal as the top fuel in America — and fast.

There’s a reason coal dominated for so long.  And still does.  For awhile at least.  Generating electricity from coal is more efficient than generating electricity from natural gas.  Coal plants are heat engines.  They produce heat to boil water.  Natural gas plants are more like the jet engines on an airplane.  Where we use the products of combustion, expanding gases, to spin a turbine.  We don’t use it to boil water.  So we waste much of the heat generated from combustion.  Resulting in lower efficiencies than a coal-fired plant.

However, thanks to hydraulic fracturing (aka fracking) the supply of natural gas is exploding (pardon the pun).  Causing prices to tumble.  And because natural gas is now so plentiful and so cheap the poorer efficiencies are less important.  Economically speaking.  So power companies are expanding their natural gas turbines.  Which helps them avoid headaches with the environmentalists.  For natural gas burns cleaner than coal.  So for the foreseeable future it will be roughly 50-50 between coal and natural gas.  But what about renewable energy you ask?  Like solar power?  When will solar power provide 50% of our electricity needs?

Each percentage point of share is roughly 40 million megawatt hours a year. By comparison, all solar projects in 2010 (the last year stats were available) produced 1.3 million megawatt hours.

About 40 million megawatt hours a year per percentage point?  Looking at the chart it looks like coal is currently at 52%.  And natural gas is at 45%.  Or thereabouts.   If you do the math that’s about 3,880 megawatt hours between the two of them.  Or approximately 96.97% of all fossil-fuel generated electricity.  While the 1.3 million megawatt hours of solar power provides about 0.032% of our fossil-fuel generated electricity.  So when will solar power provide 50% of our electricity needs?  Probably never.


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