Geothermal Energy Potential Rises

According to the linked article from EnergyDigital, geothermal energy potential in the U.S. exceeds that of coal by 10 fold. A new mapping study funded by Google shows many locations that previously had not been identified. From the article:

“This assessment of geothermal potential will only improve with time,” said Dr. David Blackwell, lead researcher of the project, according to SMU's news archive yesterday. “Our study assumes that we tap only a small fraction of the available stored heat in the Earth’s crust, and our capabilities to capture that heat are expected to grow substantially as we improve upon the energy conversion and exploitation factors through technological advances and improved techniques.”

Responding to Global Warming - Class schedule

After our discussion in class 1 today, I have decided to use the priorities arrived at by voting on the various topics to govern the amount of time spent on each topic, and to try to cover more than 6 topics. On this basis, following is the agenda for the remaining 3 classes.

Feb 6 – Solar Photovoltaic (PV), Solar Thermal and Geothermal. Solar thermal is also known as Concentrated Solar Power (CSP).

Feb 13 – Wind, Waves, Tide, OTEC and Ocean Clouds. In other words, this class will focus on the ocean.

Feb 20 – Presidents Day, NO class.

Feb 27 – Nuclear Fission, Nuclear Fusion, Biofuels and Forest preservation (see REDD). 

Mar 5 - NO Class

OTEC - Ocean Thermal Energy Conversion

Ocean Thermal Energy Conversion (OTEC) is an idea for energy production that dates back to the 1800's. From The Economist, the first OTEC power plant was built "in 1930 at Matanzas Bay, just across the Florida straits from the Bahamas, in Cuba. That successfully produced 22kW, though it was eventually destroyed by wind and waves. A mere eight decades later, the technology may at last come to fruition."

The latest commercial implementation is in the Bahamas, as described in the title link from the Nassau Guardian. 

OTEC technology utilizes the heat difference between warm surface waters, and much cooler deep ocean waters to power a "heat engine" to produce electricity. Key requirements are surface water temps of +25 deg C and nearby deep water (+1,000 ft) available for cooling. The motive chemical used is usually ammonia. The warm surface waters boil the ammonia, it passes through turbines to produce electricity, and then the cool deep waters condense it to be recycled back through the "heat engine" process.

Biobutanol, alive and well

I last looked into biobutanol back in 2006 for an Alternative Energy course. It seemed like a promising biofuel with far superior properties to ethanol, so I wondered how it was doing in 2012. Well not only is the joint venture between DuPont and BP to manufacture biobutanol still alive, a new venture has been formed in Scotland to produce biobutanol from byproducts of scotch whiskey manufacture (title link).

And if that is not inspiring enough, zebras have entered the act with a bacterium in their poop known as TU-103. This bacterium can ferment cellulose into butanol in the presence of oxygen, a real cost advantage over current processes.

Plains Zebra, Etosha National Park, Namibia by Bill Fintel

Also, bear in mind that although burning biofuels creates CO2, growing biofuels consumes CO2.

Solar Cheaper Than Diesel

Okay, solar power is still not cheaper than coal fired power plants, but this report from Bloomberg is very encouraging because it shows how fast things can change for the better (environmentally) if the economics are there. From the title link:

"The cost of solar energy in India declined by 28 percent since December 2010, according to Bloomberg New Energy Finance. The cause was a 51 percent drop in panel prices last year as the world’s 10 largest manufacturers, led by China’s Suntech Power Holdings Co. (STP), doubled output capacity."

Orbital Wobles and CO2

The linked article by Richard Black of BBC presents a concise summary of the mechanisms that cause ice ages, and also interglacial warm periods like the one we are presently in. Scientists looking back about 800,000 years at the Earth's ice age cycles believe that, were it not for greenhouse emissions, we would be entering a new ice age in about 1,500 years.

However, with CO2 levels at about 390 ppm, instead of the 240 ppm pre-industrial levels, this greenhouse warming effect is predicted to way override the orbital change cooling effects. The article also provides a brief history of why the orbital cycle changes are called Milankovich cycles.

Now no doubt the world is better off not reentering another ice age, but it will also be better off not overheating its climate, leading to more deserts, more intense storms, major sea level rise, etc.