Geothermal an all-purpose clean energy source

Michael Raffety, July 7, 2013

As a rare June California rainstorm added drama to the skies of northern Nevada a little known revolution has been slowly evolving on the ground.

In the Basin and Range geology that distinguishes northern Nevada from its southern desert area are hot springs and hot wells that are powering this state and wheeling power to California’s Independent System Operator based in Folsom.

Ormat Technologies Inc. (ORO on the NYSE) geothermal power plant in Reno puts out 100 megawatts, enough to power every residence in that city.

Not only that but several subdivisions in Reno have their own 180 degrees Fahrenheit geothermal wells that heat houses and swimming pools in Nevada’s freezing winters. The Peppermill Casino has a 100-degree geothermal source in its parking lot that helps provide hot water. One of the guides on a press tour of geothermal power June 25 even had a backyard capped geothermal well on which sat a doghouse. In the winter the dog didn’t really want to leave his warm doghouse to come inside. That changed when the cap rusted out and the freed well blew up the doghouse. (The dog was uninjured.)

But power generation is not just running hot, steamy water through a pipe to a turbine. Ormat’s success hinges on its binary technology. It’s a heat exchange system on a large scale.

Ormat’s Steamboat Springs complex is recognizable by the odd-looking collection of closely spaced pipes that hug the ground as seen from U.S. 395. Even more is visible now that the six-lane new section of 395 is open after Nevada spent 10 years building it alongside the foothills, bypassing the 45 mph section winding along the valley floor. Open about three months, it is so new it confuses new Garmins.

Another characteristic of Ormat’s Steamboat Springs’ square mile of geothermal property is pine trees and pinion pines. The presence of these trees is a tipoff that the soil is low pH and is a likely site of a geothermal resource.

Ormat’s first Steamboat Springs unit was built in 1983. The press tour that kicked off the Geothermal Energy Association’s National Geothermal Summit looked at the Ormat’s newest Galena Unit, built in 2009. Galena is two generators that together put out 36 megawatts. It is the seventh unit at Steamboat Springs.

Ormat has been able to continue generating power off its geothermal wells because it continually recirculates the water back into the ground. The water comes out of the ground at 300 degrees Fahrenheit, heats pipes containing pentane hydrocarbon, which vaporizes at 80 degrees. The pentane is binary element that turns twin turbines, one clockwise and the other counterclockwise at 1,800 rpm on both sides of the generator. Galena has two sets of generators. When the water is returned into the ground it is 100 degrees cooler. The binary element is cooled back down to a liquid with the aid of cooling fans. The hot water circulates back through the geothermal reservoir and comes back up the pipe at 300 degrees. Pressure is only 100-150 psi.

The value of geothermal is it involves no exhaust. The geothermal water is continually circulating even if the turbines are shut down. The turbines can be instantly reactivated within two minutes.

“It has incredible flexibility. We can ramp up and ramp down,” said Paul Tomsen, director of policy and business development for Ormat.

It is this “clean green” factor of geothermal power that has Ormat talking to the California ISO and will get the company 99 cents a kilowatt. for base load. Wind and solar sells for 60 cents a kilowatt because it requires gas power to back it up, according to Thomsen.

Ormat has been building its seven units on Steamboat Springs over the past 30 years.

From the control room at the Galena unit two operators monitor all seven units at Steamboat Springs and 15 “recovered-energy generation” units as far east as Chicago. These are binary systems that tap into the heat generated by natural gas line compression stations. They generate anywhere from 250 Kw to 6 Mw, partnering with companies like Northern Borders and Kinder Morgan Energy Partners.

A partial list of geothermal and recovered energy projects Ormat has developed includes places like Texas, Alaska, Germany, Austria, Canada, Hawaii, Wyoming, New Zealand, Mexico, Central America, the Azores and Kenya.

Not bad for a $1 billion market cap company headquartered in Reno. The small market cap company issued its first initial public offering of stock in 2004.

About 60 miles east of Reno Ormat has its Brady geothermal power plant. Before its geothermal water is returned to the ground it is used by a nearby onion plant to dry onions and turn them into items for the spice rack. Northern Nevada has geothermal power plants sprinkled all over the place. As the press tour bus headed two and half hors east of Reno four geothermal drilling rigs were spotted on the horizon to the south.Drilling is the biggest risk in he geothermal business, costing $5 million-$8 million and  not always proving productive. Most wells go 1,800 feet deep, though some will go 9,000 feet deep.

Geothermal is not the exclusive province of Nevada. The Geysers in Sonoma County are home to 15 steam operated power plants by Calpine Corp. that produce 725 megawatts of electricity, enough to power a city the size of San Francisco. Calpine rejuvenated the Gesyers by injecting wastewater from Lake County and the city of Santa Rosa.

Ormat has its eye on some geothermal possibilities in Southern California. Nevada has always been noted for its hot springs, from Wally’s Resort to Black Rock Desert, though some are too hot to touch. Forty states have hot springs, including Kansas, which indicates the possibility of geothermal power generation. Oregon likewise has hot springs, one heating a locally famous swimming pool outside Baker City called Radium Hot Springs.

About 150 miles east of Reno and 60 miles south of Winnemucca is the Florida Canyon Mine. When the open pit mine dug down deep enough to hit geothermal water it found that out when it drilled holes and packed in dynamite to be set off the next day. When the miners showed up the next day they found the dynamite had already gone off, set off by the heat near the cap of the geothermal area.

For the time being the mine’s current owner, Jipangu International Inc. out of Japan is putting its mining efforts into the nearby more lucrative Standard Mine, though a permit may be sought in the near future to reopen the Florida Canyon Mine.

What remains of the Florida Canyon Mine, originally opened in 1986, is a mountain of gold-bearing ore — 400 million tons sitting on a thick plastic sheet and covered with drip irrigation that has a weak arsenic solution that leaches through the heap of material and send out 50 ounces of gold-silver combination per day. Half the mountain of material dug out of the open pit mine has been restored to natural vegetation and yet gold is still leaching out of the bottom even though it is no longer receiving the arsenic irrigation, according to mine superintendent Joel Murphy.

The leach field takes 30,000 gallons of water a day. Half a million gallons will evaporate on a hot day. So the mine operators have to do a lot of pumping to keep the heap leach field watered. The water they have to work with is 225 degrees F. It is fed into a pond where it is cooled and then sent to two pump houses. One of those pump houses feeds into a 50 Kw generator that helps reduce the electrical expense of pumping and provides additional cooling for the water.

This 50 kw generator is an experiment backed by a nearly $1 million Department of Energy grant, which is why Geothermal Summit participants were all abuzz about President Obama’s June 25 speech on reducing carbon emissions.

The Electra Therm Inc. system fits in a small cargo container, complete with forklift slots underneath. The heart of the generator is a titanium heat exchanger. Geothermal hot water runs through the heat exchanger and heats a refrigerant called penta fluoropropane lubricated with a little oil. It is also called HFC R49F1 and it boils at 58 degrees F.

The generator unit is safe enough to put inside a building, said  systems engineer Andrew Oxner.

The titanium in heat exchanger is very lightweight. Oxner, on the way to the mine, told a story about how America got a large supply of titanium. A geology graduate of the University of Nevada, Reno, Oxner recalled finding the remains of an SR-71 Blackbird spy plane in the desert that had hit the ground at Mach 4 after the crew had made the highest altitude ejection in 1969. Russia has the largest supply of titanium. The U.S. imported a lot of titanium in the late 1950s “to make golf clubs.” Instead it went into making the SR 71, which in turn was used to spy on Russia.

Now that most of the SR-71s have been junked they may be reincarnated as a titanium heat exchanger on an Electra Therm 4000 portable 50 kw geothermal generator, remotely operated by a cell phone app.


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