Entrepreneur demonstrates portable power prototype

Karl, a mechanic and owner of Chena Hot Springs Resort, plans to market a portable geothermal power plant in an energy marketplace yielding increasing numbers of alternative energy ideas.

The project's technology mirrors that of Karl's four-year-old geothermal plant at Chena Hot Springs east of Fairbanks. Where the resort's power plant took up a building, the prototype fits on two flatbed trucks.

Karl recently demonstrated the prototype in downtown Fairbanks, near the back doors of Aurora Energy's Chena Power Plant. Hot water — a byproduct of the Aurora plant — fed Karl's mobile ORG (organic Rankine Cycle) plant, which spit 200 kilowatts of electricity into Fairbanks' power grid.

The Rankine Cycle is the basis of most modern electric power plants. A heat source boils water to create steam, which turns a turbine. The steam then travels through pipes into a condenser, which converts the steam back into water, and the process repeats.

Because the water at Chena Hot Springs isn't boiling hot when it comes out of the ground, Karl designed a power plant that uses a chemical with a lower boiling point. The hot water heats up the chemical, which turns into steam and works the same as in an ordinary Rankine Cycle.

"You hear that? It's purring like a kitten in a creamery," Karl said. The demonstration is producing free electricity for Aurora without emissions, he said.

A business team will next send the prototype — built to operate from atop the two trucks — to Las Vegas, Wyoming, and then Florida for commercial demonstrations. The business team consists of Quantum Resources Management, Pratt & Whitney Power Systems, United Technologies Research Center and Karl's Chena Power.

In Florida, the power plant will use hot water created as a byproduct of oil extraction. In preparation for that test, Karl incorporated an oil-and-water separator into the prototype design.

Karl said he hopes to build and lease around 1,000 models in the next three years with Chena Power. He estimates each plant will cost roughly $300,000 or $400,000 to build. Karl said the demonstration work will help potential clients see that each plant needs only minimal maintenance, can operate self-contained at an average oil well, and doesn't need permits for ground work or construction.

Because it feeds on water heated by the Earth, Karl calls geothermal a "second bite at the energy apple." His demonstration downtown actually represented a third bite: It ran on leftover hot water at the Aurora plant's district heat system, which itself employs waste heat from the plant's electric generation to heat a few hundred downtown homes and buildings.

"We're just using the leftovers," Karl said.