Jet engine helps produce power from natural gas - with surplus for sale

The argument that cogeneration of electricity - including the production of heat and power from natural gas - is a feasible option for meeting electricity demands into the 21st century has received an important boost here, with the help of a 20-megawatt power plant and a jet aircraft engine.

The $11 million cogeneration power plant of the Great Western Malting Company not only provides a cost-competitive source of heat, but the electric output generated is sold to the Clark County Public Utility District. The power generated is sufficient to serve some 8,000 households.

At the heart of the new power plant is a General Electric Company LM 2500 turbine engine, normally found in DC-10 jet aircraft. It produces both heat and the electricity that flows to a substation of the utility district.

This application of a jet engine to earthbound cogeneration of power recalls the very first use of a jet in an industrial operation, about 1960. Some 20 years ago, Columbia Gas System installed a Pratt & Whitney jet as a source of gas-fired power in a pumping station on its natural gas pipeline passing through Casey County, Ky., at a point known locally as Possum Trot.

Meanwhile, in an ongoing test in Portland, Ore., a natural gas-fired fuel cell has been on site for nearly two years at a local commercial laundry, providing heat for plant operations and electric power, which is sold to Portland General Electric Company.

The Portland project, under supervision of Northwest Natural Gas Company engineers, is part of a national test of fuel cells built at United Technologies Corporation, in Hartford, Conn., and being studied under a 14-year, $150 million research and development program in which some 30 utilities are taking part.

The cogeneration project here grew out of a five-year search ''for an imaginative way to supply advanced technologies to reduce our energy costs and improve efficiency,'' says Tod R. Hamachek, president of Great Western, who said the alternative was to ''eventually close the plant'' with a loss of 150 jobs.

Mr. Hamachek called the cooperative planning for the project, which included the Clark County utility district and Northwest Natural Gas, ''a model of what industry can do without government subsidy.''

Terence J. O'Brien, vice-president for operations, said that cogeneration is ''a better source of energy than either nuclear or coal generation'' and that the jet has operated since going on line in December at a high level of efficiency.

''Five years ago,'' Mr. O'Brien said, ''we would have needed an engine three or four times bigger to do the same job.''

The Northwest Power Planning Council's Regional Conservation and Electric Power Plan, adopted in April, includes cogeneration, and Hamachek said the council had called on the Bonneville Power Administration ''to preserve this option in meeting future demand.''

Adoption of the cogeneration option by the council seems to reflect concern for possible alternative power sources in the Northwest following the multibillion-dollar collapse of the Washington Power Supply System's nuclear project in Washington State.