Comments on: Coal to Lead U.S. Energy Mix Even as Many Older Plants Convert to Natural Gas http://cleantechnica.com/2011/07/18/coal-to-lead-u-s-energy-mix-even-as-many-older-plants-convert-to-natural-gas/ Clean Tech News & Views: Solar Energy News. Wind Energy News. EV News. & More. Tue, 30 Dec 2014 01:04:00 +0000 hourly 1 http://wordpress.org/?v=4.0.1 By: http://gminingguide.com http://cleantechnica.com/2011/07/18/coal-to-lead-u-s-energy-mix-even-as-many-older-plants-convert-to-natural-gas/#comment-102006 Tue, 19 Jul 2011 07:47:00 +0000 http://cleantechnica.com/?p=28963#comment-102006 As petroleum reserve exploration declines while the price of fossil fuels increases, the extraction process has become heavily dependent on secondary and tertiary recovery to augment the output of proven reserves. Secondary recovery is vital to maximizing the net energy gain as the pressure of an oil

]]>