Drilling crews recently completed an 1,100-foot-deep exploratory well at the base of "M" Mountain. The exploration resulted in, more or less, the anticipated result — the discovery of geothermally heated water.

The heated water could potentially be used to heat every building on the main campus of New Mexico Tech, eliminating virtually all use of natural gas. The projected savings to New Mexico taxpayers could be around $500,000.

The bill for the changeover from natural gas to geothermal heating is estimated at $5 million, most of which would be covered by federal stimulus funds administered through the U.S. Department of Energy.

Dr. Mark Person, the Tech hydrology professor leading the project, calculates the investment could pay for itself in fewer than 10 years. "We'll essentially stop buying natural gas from the City of Socorro," Person said, in a Jan. 27 interview. "We estimate that will save about $800,000 per year in natural gas charges."

However, the water from the geothermal well is not quite hot enough to get the job done. Heat pumps will be needed to boost the temperature.

"So, we'll have to buy more electricity to run the heat pumps," Person said.

The professor calculates the increased electricity use will cost the university about $300,000 per year, for a net savings every year of about $500,000.

On the surface, the plan is simple. First, pump geothermally heated water up from below the ground. Then, circulate it through heat exchangers to transfer the free geothermal heat to the campus hot water loop system, which provides heat for the campus buildings and hot water to the campus plumbing. Then put the geothermal well water, now significantly cooler, back into the ground.

In fact, the plan is anything but simple, due to some large and potentially insurmountable challenges. The project so far has gone forward on the basis of a series of well-educated guesses, and has already encountered some unforeseen stumbling blocks. Trial and Error

The first attempt to establish a source of hot water close enough to the surface to make the project feasible burned through $800,000 and multiple drill bits before grinding to a halt. The work was begun in 2006, by Dr. David Norman, a professor of geochemistry who died in 2008. Enough information was gained from Norman's efforts, however, to warrant a second try.

"The current well was much cheaper but it was still very challenging," Person said. "There were multiple cave-ins and bore-hole collapse problems. But, in the end, we were successful in getting down and proving the resource."

Person did prove the resource, but it wasn't as hot as expected. He anticipated finding geothermal fluids at a temperature of at least 160 °F. What he got was only 107°F, which is not sufficient to heat the water in the campus loop to the required temperatures. Again, the project threatened to grind to a halt, until he found a workable solution.

"Daniel Hand, from Sustainable Resources Inc., who is working on this project, found a work-around to solve this problem," Person said. "The way we can make this system work is to add heat pumps."

The heat pumps extract additional heat from the geothermal fluids, and add it back into the heat loop system. The estimated price tag is $1.9 million, an extra cost that wasn't included in the original grant from the U.S. Department of Energy. Person is working with the DOE to come up with additional funding.

If Person is successful in obtaining additional funding for the heat pumps, there is still at least one more potentially project-ending obstacle. The fluid from the 1,100-foot geothermal well is slightly saline. When it leaves the campus hot water loop system it has to be reinjected into the ground, below the shallow aquifers that are used by the city of Socorro.

"We'll have to drill a very expensive well on campus to reinject the fluids," Person explained. "We'll have to find a deep permeable formation to reinject into, and we may have to go as deep as 3,000 feet."

Where the money will come from for the reinjection well has yet to be determined, but the estimated cost is $1 million.

"We have gravity data and a magnetotelluric survey that represent the best guess we have about what we'll find when we drill that well," said Person, "but we don't really know until we actually drill. So the cost estimate is just that, an estimate."

Another unknown is what will turn up in the environmental assessment that's required before the project can even go much further.

Five million dollars may seem like a lot of money to sink into a project that has already encountered major pitfalls and may very well encounter more. However, Person stressed that all exploratory projects have risks, and this one dovetails perfectly with another project Tech will have a hand in.

"President (Dr. Daniel H.) López just secured funding for New Mexico Tech to do a statewide geothermal assessment, to quantify and identify where our geothermal resources are, and that's just starting up this year," Person said. "So this is the year for geothermal energy at Tech, both in terms of developing a district heating system and also trying to work with the state to better characterize where the geothermal resources are and trying to encourage their development."

In the big picture, Person's work will help Tech become a natural laboratory for the rest of the state.

"There are other examples, other parts of the state where they have these warm fluids, and this is going to be a demonstration of what you can do with these resources," said Person.

A large part of Person's mission is to develop an educational and outreach program to help other parts of the state identify their resources and figure out how they can be used.

"These other places, like Truth or Consequences, can apply to the DOE for funding to develop them, for district heating, for aquaculture, for geothermally heated greenhouses, and so on."

Socorro, too, could see long-term benefits from the geothermal research Person and his colleagues are doing now.

"There's the potential down the road to develop greenhouses and aquaculture facilities, and for biofuel," he said.

One way to make biodiesel is to grow huge vats of algae and extract the fat in a process similar to the way diesel is made from corn.

"Algae is the fastest growing form of life on earth, and has less of a negative impact than corn based ethanol," Person said. "This temperature is perfect for biodiesel, and professor Corey Leclerc in the Chemical Engineering Department at NM Tech is very interested in looking into pursuing this."

Ultimately, Person is determined to see the project come to a successful conclusion. "We could be saving a lot of energy in New Mexico by using heat pumps and using our natural hot waters, our indigenous energy resources," he said. "It's just the capitalization, the up-front costs."

If Person is successful, the city's revenue from the sale of natural gas could be unfavorably affected. However, in a Feb. 1 interview, Mayor Ravi Bhasker said that what benefits the university and the taxpayers ultimately benefits the city as well. "We're very happy that they're working to save taxpayers money," Bhasker said, "and we're here to help them in any way we can."

Hand, the engineer who has been working closely with Person to provide solutions, shared his perspective in a Feb. 8 telephone interview.

"There's a time coming when it's going to be high noon for natural gas," he said. "Geothermal energy is a local resource. They can't take it away from us, and it's not subject to price fluctuations."

In the long term, Hand says it's a smart choice.

"The people working on geothermal resources are looking to build a different future," he said. "I want to be part of that."

Contact Suzanne Barteau