« Back to Home Page

What’s Hot About Geothermal Power

| Wednesday January 14th, 2009 | 8 Comments

jen%20in%20hard%20hat.jpgGeothermal energy is all the rage these days, with the talk of its capability to solve all our energy woes. I had a chance to visit The Geysers, North America’s largest Geothermal operation (generating about 40% of the geothermal power in the US) and I’ve gotta tell you, I’m more fired up than I was before. (I can’t promise not to throw a couple more bad puns in there before this post is through but I hope you’ll bear with me)
Green, Clean Operation
Geothermal power produces emission free, steam-based energy by utilizing heat from the earth’s core. It is so cool. Each plant will have a slightly different set-up based on the rock formations below the surface, but here’s how it works at the Geysers. Two miles below the surface of the earth is hot magma (say it with me: liquid hot mag-ma). One level above that is a porous seabed rock, filled with thousands of tiny cracks. The water from the ancient seabed is filtered through those cracks, and heat from the magma turns that water to steam. The plant works by drilling a narrow hole down 2 miles to the porous rock level, and the steam shoots up the hole. Pressure from the steam turns a turbine, and then, boys and girls, electricity is made.
Here’s a picture of the plant:
plant%202.jpg


Big Money, Big Power
The Geysers is operated by Calpine, an energy generation company in northern California. Calpine operates 19 power plants at the Geysers, employs 350 full time staff, and is capable of generating 725 megawatts of power– enough to power 40,000 homes! The firm also has a fleet of natural gas powered plants. All in all, it’s one of the cleanest power generation companies in the US, and it supplies about 20% of California’s renewable energy. Renewable energy is big business in California, where the state’s utilities are required to source 20% of their power from renewables by 2010 as well as 33% by 2020. This means that locally produced clean power like geothermal will continue to be in high demand. The high demand is evidenced by a higher premium for renewable energy– around 11c/kwh for renewable power compared to an average price of around 7.5c paid for energy that doesn’t meet the renewable standard. (source)

Closed Loop System
Over time, that steam, the bread and butter of a geothermal operation, can be depleted, since it’s blowing out at a constant rate. The Geysers plant has been operating since 1960-that’s a lot of hot air. The folks at Calpine have figured out an innovative way to replenish their cash cow. They have contracted with the city of Santa Rosa as a handy disposal for wastewater produced there. 4,015 million gallons of treated wastewater make the 40-mile trek each year to the Geysers, where it’s sent down old shafts to refill the porous rock layer. This water quickly becomes heated and goes up the operational vents as steam. The whole process can take an hour or a day-it’s tough to tell for sure because it depends on where the water goes 2 miles underground, but it’s pretty fast all around.

Old Faithful Plugging Away

Whenever I go on tours like this I’m always struck by how not ecologically minded the folks working at the plant are. At the Geysers, each plant is maintained by a single tech who works a 12 hour shift. The tech we spoke to had been working at the plant for 25 years-and he gave Homer Simpson a run for his money with mutton chops, 70s child molester glasses, suspenders over Carhartts and an expression on his face somewhere between surprise, irritation, and boredom at the presence of these environmentalists drooling over his plant. This man was no treehugger. But he doesn’t have to be. The Geysers has been operational since the 60s not because it’s green or trendy but because the economic model for producing electricity makes good business sense. These are the types of solutions we really need for the green revolution.


▼▼▼      8 Comments     ▼▼▼

Categorized: Renewable Energy|

Newsletter Signup
  • Ashwin

    This line really resonated with me! “This man was no treehugger. But he doesn’t have to be.”
    (I was into the Austin Powers reference too…)

  • Gert

    Epic description of the operator! Hilarious!

  • http://GlobalPatriot.com Global Patriot

    There are many opportunities around the globe to tap into geothermal resources. It’s not a universal solution by any means, but can collectively make a measurable change in the consumption of fossil fuels.

  • http://jlaine.net Jarkko Laine

    You don’t have to have big plants to tap into geothermal power, either. Using geothermal wells and heat pumps you can basically cut the heating/cooling energy used by a house to (to, not by) a third. That should make them very lucrative for any new buildings. Despite their high initial costs, their effectiveness makes them pay the upfront cost back in a couple of years and past, that – pure profit.

  • http://www.maxbakker.com Maxitaxi

    Keep in mind that geothermal is an excellent source of baseload power, i.e. a direct substitute for fossil fuel as it can be dispatched 24/7 to meet fluctuations in power demand. As long as we lack real storage capability for solar PV, wind and even current CSP technology with a storage capability, (tends to be around 2-3 hrs), geothermal is really the only clean substitute for baseload power.

  • http://www.cleanedison.com/geothermal.html geothermal installer school

    Besides of geothermal energy solar and wind energy had been pretty famous now a days

  • http://WWW.buildagreenbusiness.com/ energy audit training

    Excellent article, thanks for the info.

  • http://WWW.buildagreenbusiness.com/ energy audit training

    Excellent article, thanks for the info.