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Steam Heat & Power: Journey to the Center of the Earth

| Thursday September 4th, 2008 | 2 Comments

Geothermal energy is attracting a lot of long overdue attention recently. Gathering in Reykjavik last week officials from Australia, Iceland and the U.S. signed a charter to establish the International Partnership for Geothermal Technology, reported Greenbiz.com.
A signal of “the commitment of the three countries to aggressively foster and promote cutting edge geothermal technologies to promote energy security and address global climate change,” according to the U.S. Dept. of Energy media release, the announcement comes hard on the heels of Google announcing that it will invest $10 million in enhanced geothermal systems as part of its “Renewable Energy Cheaper than Coal” program.


Largely Ignored & Untapped
Radiation emanating from the earth’s core creates hotspots just below the earth’s crust, heat sinks that can be more effectively and cheaply tapped into using enhanced geothermal technology that has been in development since the 1970s. Doing so would provide a source of large, relatively accessible steam heat capable of generating reliable, clean, renewable baseload electrical power in regions across the U.S., according to a recent report published by experts at MIT.
Geothermal currently provides less than 1% of the world’s power though it could supply as much as 20% in the coming decades, according to the study.
“Geothermal energy could play an important role in our national energy picture as a non-carbon-based energy source,” Nafi Toksoz, professor of geophysics at MIT, said in an interview. “It’s a very large resource and has the potential to be a significant contributor to the energy needs of this country.”
Long Overdue
800px-Iceland_Geothermal_facility.jpg “From our home on the earth’s thin crust, it’s hard to believe that 99.9% of the earth’s volume is hot enough to boil water,” writes Clearlight Foundation founder and geothermal power advocate Thomas Blakeslee.
“Atomic decay inside of the earth heats its molten core to a temperature that is hotter than the surface of the sun! To harness this geothermal power, we need only drill through the crust and use that heat to boil water to drive turbine generators. This water can be reinjected into the earth in a closed loop.”
The discovery and extraction of relatively abundant and cheap sources of coal, oil and natural gas in the past century, along with all the money making possibilities, power and influence associated therewith, effectively moved government and society off the simpler, cleaner and more direct use of geothermal and other renewable energy resources, according to Blakeslee.
It’s about time…and political will
“Clearly we love to gather fuel because, though we can boil all the water we want for free using the earth’s geothermal heat, we spent virtually nothing on geothermal research last year and plan to spend only $30 million next year,” he writes.
“It seems that our $2 billion in subsidies to fuel interests last year paid for a lot of lobbying and influence. We need to start in a new direction in our energy policy but can’t seem to escape the past. Subsidies are often self-perpetuating.”
Geothermal power has been around for a long time, producing heat and power cleanly and cost-effectively, but it’s been largely ignored, he notes. “The world’s first geothermal power plant was built in Larderello, Italy in 1911. It is still producing enough power for a million homes today. Geothermal power already supplies 26% of electrical power in Iceland and the Philippines and 5% of California’s at prices that are competitive with coal power.
“Geothermal power plants run 24 hours a day with an uptime of over 90%. They require no fuel and produce no pollution. Coal and atomic power plants need much more maintenance downtime, so they only operate an average of 75% and 65% of the time. Wind and solar power are even worse, producing an average of only 30% and 24% of their rated power,” he points out.


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  • GeoGuy

    Blakeslee, who is quoted in this article, is just wrong about the Earth’s core:

    “Atomic decay inside of the earth heats its molten core to a temperature that is hotter than the surface of the sun!”

    First, the molten outer core is not due to this decay. It got that way during formation of the Earth, and is kept that way by the heat of crytallization as it adds to the solid inner core. Since heat moves from high temperatures toward low ones, and the core temperatures exceed the mantle temperatures, then the flow of heat is from the core to the mantle and toward the surface, not the other way around.

    Second, as the MIT report mentioned above says, the heat seen in crustal rocks derives both from “tectonic” sources and from the decay of radioactive rocks ***concentrated in the crust*** at around 10 km.

    This is not to say that other portions of the Earth don’t have radioactive rock components, but only that the heat “signal” seen in crustal rocks is dominated by radioactive decay in deep crustal rocks, and by tectonic heat, which may include heat conducted from the core, but also by near-surface proximity to magma and the mantle.

  • http://www.clrlight.org tblakeslee

    Actually the heat left over from the earth’s formation is only about 5-10% of the heat currently at the core. Here is a reference:
    http://www.physorg.com/news62952904.html