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Friday, May 11, 2012

Low-Temperature Geothermal?


If you are like me you probably have never heard of low temperature geothermal. Imagine my surprise when i read this article.

It appears as though this (low temperature geothermal) has been a burgeoning new industry. And this is to prove what our research dollars are doing for us. Without federal and state funding these people would get nowhere!

As Doug Glaspey has recently said “We must look at new technologies on all fronts – both exploring for new resources and for developing and operating those new resources — so we would like to see additional funding from the DOE [U.S. Department of Energy] in the geothermal technologies program.”

And as is mentined in said article they need more drilling technology. Why not look to the oil and gas industry for their advancements in drilling technology? I mean they more than likely already have the technology that this industry now requires.

Now onto specifics about low temperature geothermal. Traditionally geothermal has required temperatures to be above 360+ degrees Fahrenheit at the source. Such has been increasingly hard to find. All low temperature geothermal uses sources below the 300 degree mark, sometimes as low as 160 degrees Fahrenheit! According to the SMU Geothermal Laboratory

this is the real game changer right now.

The Organic Rankine Cycle is commonly used for these purposes. Wikipedia has an excellent article on the organic Rankine cycle for those of you who are willing to read it. As is noted in the Wikipedia article temperatures below 100 degrees Celsius this process becomes rather inefficient. So basically they are trying to do the near impossible in the first place!

The key to this type of plant is the using of the proper fluid for the heat exchange process. Typically they have relied on traditional refrigerants such as R-22, which has a very low boiling point of -41 degrees Fahrenheit. Now I am not 100% positive about this but is R-22 almost as bad for the atmosphere as R-12? I believe R-22 systems are very rare and difficult to find these days for this fact.

Despite a relatively quiet 2011, there have been a few small low temperature geothermal project go online in the past year. The Beowawe Geothermal Facility in Nevada added 2.5-MW of low-temperature geothermal power capacity to its existing 16.7-MW geothermal plant that went online in 1985 with the help of a DOE loan. This site has been experiencing resource decline in recent years. To solve this issue, Terra-Gen Power and TAS Energy used a DOE loan to incorporate low-temperature technology at the site-- yet another example of how the Federal Government and corporations can work together to achieve their goals!

“An increase in the DOE’s geothermal budget allowed this project to become a reality, which lead to additional jobs and promises more clean renewable energy for the future as this project paves the way for additional low temperature binary projects in Nevada and elsewhere,” said Jim Pagano, CEO of Terra-Gen Power.

With energy created from a 205°F resource, Beowawe confirms the technical and economic feasibility of low-temperature electricity generation. It uses new binary expanders that allow the use of lower resource temperatures for geothermal and waste heat applications. An axial turbine using R134a and R245fa as the primary working fluid, covers gross power output from 500-kW – 5.0-MW output with temperatures from 200 – 500°F (97 - 260°C).

But there are more examples of government and corporations working together in order to achieve their goals. And in 2006, the Chena Hot Springs plant in Alaska set the record for the lowest-temperature production at 165 degrees Fahrenheit – and still holds it today. The 400-kW plant was the first low-temperature geothermal plant in the world and uses United Technologies Company (UTC) generators to produce power. Chena Hot Springs has reduced the cost of power from $0.30 per kWh to $0.05 per kWh and has helped to lift the veil on Alaska’s geothermal potential.

But not everyone in the geothermal game is stuck on such old technology that relies on the Rankin cycle to produce power as there is a new player in this game-- known as the Kalina cycle. And this process only uses water and ammonia for its fluid instead of R-22 so it is more eco-friendly. See it relies on ammonia as its fluid.

But this process makes use of two different fluids which can be adjusted to fit the application. This allows for the Kalina Cycle to be used over a wide range of temperatures. The Kalina cycle was developed in the 1980 by a Russian engineer Alexander Kalina, and takes its name from him. And according to the Kalina Cycle Website it can boost efficiency from 10% all the way up to 50%!

This technology was first put to the test in Húsavík, Iceland in July 2000. The Orkuveita Húsavíkur plant uses geothermal resources with a typical temperature of 250°F. The 1.6 MW plant, still in operation today, produces enough reliable energy to power 80 percent of the town, according to the article. Among other benefits, the hot fluid that leaves the plant is used in the town’s heating system, heats greenhouses and the town’s swimming pool and assists in melting snow.

This technology has an Oregon State community hoping for the same results as Iceland got out of it. In the Klamath Basin Wildlife Refuge where energy and water are becoming a major issue, experts are testing for Kalina geothermal potential. The refuge has a water shortage problem, and energy price hikes have made water pumping too costly. When drilling for water in 2002, experts found a 200°F geothermal resource — perfect for the Kalina cycle.

“We had a need for cheaper power, they wanted to put this technology to work,” said Ron Cole, refuge manager, to Sustainable Oregon. The $10 million project is said to have investors ready to move forward once the environmental regulations are cleared — construction could start by the end of 2012. If the project is a success, it may influence four other sites in the area, according to Sustainable Oregon. I for one say kudos to Oregon state for its effort in geothermal energy!

Of course the federal funding for such projects have been waning ever since the TEA Party has taken control of the house. Of course why this is of major importance is because they control the House of Representatives Ways and Means Committee which I can tell you is where most projects like this are either born or die. So at this point I would have to question whether or not they can get their much needed funding, as I can tell you they are all for coal and polluting our environment in a huge way-- their mindset is very regressive and they think we should continue on our way to global warming!

1 comment:

  1. Geothermal is one of the great way to save the energy. It helps you to controlled the temperature and get it down.

    ready to install geothermal

    ReplyDelete