Peppermill now studies use of geothermal for electricity

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Next up for the Peppermill Resort Casino after bringing online a $9.7 million geothermal well that will account for 100 percent of the property's heating needs this winter?

Using the geothermal heat source to generate up to a third of the resort's power needs.

The idea to add to the property's existing geothermal capabilities a geothermal well was dug at the property in the 1980s came about after completion of the property's new Tuscany Tower and spa/pool-area expansion, says Dean Parker, executive director of facilities.

An existing geothermal well, a relatively shallow and low-temperature source, was capped during the massive tower expansion project, and as it was brought back online it provided about 30 percent of the resort's heating needs, much to the surprise of Peppermill executives.

"We knew it would help us on the heat side, but we didn't know how much it would help us," Parker says. "If we went deeper and found hotter water, what could we do? We knew natural gas isn't going to get any cheaper."

Drilling commenced, as did some sleepless nights as the cost of drilling closed in on $4 million without locating a hot water resource.

"When we drilled down 4,400 feet, and we had a dry well, we had a heart attack," Parker says. "There were no guarantees that when we drilled we would hit hot water. It was a huge risk for the ownership."

Drilling at depth requires liquid mud to keep the drill bit lubricated and cool, and the heat at such extreme depths baked the drilling mud into cement, which filled small fissures in the rock surrounding the bore hole and kept geologists from discovering any water. Once the hole was "scrubbed" of the drilling mud, and the mud was pumped back to the surface, 175-degree water began flowing.

"It just shot up like a geyser, and we knew we had a very good well," Parker says.

The new well is 4,421 feet deep basically reaching down to sea level. The well flows naturally, or under artesian power, at 1,250 gallons a minute. Since that flow rate overpowered the existing reinjection well, where discharge water is returned to the source so the source is not depleted, another reinjection well was drilled and 1,500 feet of piping was laid through the property's parking lots.

Thousands of feet of hot- and return-water piping also snake through the bowels of the casino. Parker expects that the Peppermill won't need to use any of its four massive boilers this winter a conservative cost savings of $1.9 million annually.

"We feel we have enough heating capacity on this geothermal well to heat the entire campus," Parker says.

The system was designed with 20 to 30 percent additional capacity as well, in case the property undergoes expansion again.

Peppermill engineers now are contemplating power generation from the geothermal well. The resort's needs are significant, about nine to 10 megawatts annually. The well could account for about three to four megawatts of power.

Supplemental power could best be used during peak power periods, such as hot summer days, when rates from NV Energy are higher.

"We are looking at something that would be a supplement, and that in itself would be a huge savings. It is vital for us to control the energy we use," Parker says.