News24

Volcano power may boost green energy

2012-01-15 10:20

Seattle - Geothermal energy developers plan to pump 91 million litres of water into the side of a dormant volcano in Oregon to demonstrate new technology they hope will give a boost to a green energy sector that has yet to live up to its promise.

They hope the water comes back to the surface fast enough and hot enough to create cheap, clean electricity that isn't dependent on sunny skies or stiff breezes - without shaking the earth and rattling the nerves of nearby residents.

Renewable energy has been held back by cheap natural gas, weak demand for power and waning political concern over global warming.

Efforts to use the earth's heat to generate power, known as geothermal energy, have been further hampered by technical problems and worries that tapping it can cause earthquakes.

Even so, the federal government, Google and other investors are interested enough to bet $43m on the Oregon project.

They are helping AltaRock Energy of Seattle and Davenport Newberry Holdings of Stamford, Connecticut, demonstrate whether the next level in geothermal power development can work on the flanks of Newberrry Volcano, located about 30km south of Bend, Oregon.

Green energy

"We know the heat is there," said Susan Petty, president of AltaRock. "The big issue is can we circulate enough water through the system to make it economic."

The heat in the earth's crust has been used to generate power for more than a century.

Engineers gather hot water or steam that bubbles near the surface and use it to spin a turbine that creates electricity. Most of those areas have been exploited.

To tap that heat - and grow geothermal energy from a tiny niche into an important source of green energy - engineers are working on a new technology called Enhanced Geothermal Systems.

"To build geothermal in a big way beyond where it is now requires new technology, and that is where EGS comes in," said Steve Hickman, a research geophysicist with the US Geological Survey in Menlo Park, California.

Wells are drilled deep into the rock and water is pumped in, creating tiny fractures in the rock, a process known as hydroshearing.

Cold water is pumped down production wells into the reservoir, and the steam is drawn out.

Similar to fracking

Hydroshearing is similar to the process known as hydraulic fracturing, used to free natural gas from shale formations. But fracking uses chemical-laden fluids, and creates huge fractures.

Pumping fracking wastewater deep underground for disposal likely led to recent earthquakes in Arkansas and Ohio.

Fears persist that cracking rock deep underground through hydroshearing can also lead to damaging quakes. EGS has other problems. It is hard to create a reservoir big enough to run a commercial power plant.

Progress has been slow. Two small plants are online in France and Germany. A third in downtown Basel, Switzerland, was shut down over earthquake complaints. A project in Australia has had drilling problems.

A new international protocol is coming out at the end of this month that urges EGS developers to keep projects out of urban areas, the so-called "sanity test", said Ernie Majer, a seismologist with the Lawrence Berkeley National Laboratory.

It also urges developers to be upfront with residents so they know exactly what is going on.

Comments
  • Roberto - 2012-01-15 10:56

    If it works, I'll apologise, but I think it's unwise to screw around on the intestines of a volcano. Somebody's going to get hurt, and I doubt it'll be the volcano.

  • Garth - 2012-01-15 11:36

    My questions are the following: Where is the 91 million litres of water going to come from? Is the steam going to be condensed and then cooled before returning to the fractures, thereby recycling the water? I know that Oregon is a `wet' state, but 91 million litres of water is a large `chunk' to remove from the surface in one go.

      Sharon - 2012-01-15 11:58

      also, why use water, boiling point 100 degrees, why not pipe oil in a closed circuit, cooking oil boiling point 246 degrees, when it reaches the surface run it through a heat exchanger far more efficient utilization of the heat and less hazardous for the environment.

      Squeegee - 2012-01-15 12:06

      The energy used to pump the water into the volcano will probaly be several times the energy generated (if it works) unless it is cooled and recycled again and again. Still, there will be loss of water and more will have to be pumped in - using power.

      Stirer - 2012-01-15 13:29

      Squeegee, the energy generated by a volcano would be in significant numbers of magnitude greater than the energy used to pump water into the volcano. it would be mere "pocket money" to a billionaire - once they have the infrastructure in place. Sharon, the use of oil would not be a solution. With water, the heat from the volcano converts the water to steam under significant pressure. the boiling point of either water or oil is not a consideration. The temperature in a volcano is greatly in excess of 1000 degrees 1100 to 1400 degrees). I doubt that thoughts of recycling water or oil in the process, is even on the table.

      UweK - 2012-01-16 16:46

      technically the steam is recycled...its called rain, dew, frost or snow...depending on where and the local weather conditions. PLUS remember that water is clean, 100%, when it comes drown wherever it does. Evaporated water doesn't take the chemicals and pollutants with...

      Zion - 2012-01-17 09:17

      Sharon: 10 out of 10: A heat exchanger system is by far more efficient than water in cracks.

  • francisenrudi - 2012-01-15 14:03

    WELL I WOULD SAY GO FOR IT

  • Zion - 2012-01-17 09:14

    Yes, they will carry on with this new great leap in energy technology. That is until the fractures collapse and plug the volcano's natural route to the surface. Guess what? BOOOOOM and you will think you are back in Sicily and Mt. Etna has come to fetch you.

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