How profitable has it been over the past five years to own stock in PacifiCorp, parent company of Utah Power & Light? Quite satisfactory, according to the Portland, Ore.-based company's 1990 annual report mailed to shareholders this week.

In its financial review, PacifiCorp, which acquired UP&L in 1989, shows a total investment return compounded over the period 1985-1990 of 15.1 percent, topping the Standard & Poor's Electrics' stock price appreciation and dividends return of 14.0 percent and the S&P 500 return of 12.0 percent for.Not bad for a conservative, low-risk investment.

For 1990, the company's consolidated financial results came in a bit below its goals although each of its core businesses posted record results, says Al M. Gleason, president and chief executive officer, in his message to shareholders.

For the year, PacifiCorp's net income rose 2 percent to $474 million. Earnings per share were also up 2 percent, to $1.85. Dividends paid for the year increased 4 percent to $1.41 per share.

The company credits much of that growth to the UP&L acquisition, a merger which Gleason said created "greater strength and efficiency, while altering the company's future."

Benefits of the merger, now two years old, stand at $147 million, according to the report, 25 percent above initial expectations. Power supply advantages alone accounted for some $45 million of the total. (Utah Power and sister company Pacific Power benefit from having different seasonal peak demands and also from having increased access to wholesale power markets.)

PacifiCorp credits record-setting performances by its coal-fired electric generating power plants for much of the gains. As a system, the plants ran at a combined capacity factor of 83 percent in 1990 while completing their sixth consecutive year of lower per-unit production costs.

"The dedication of the (Utah Power and Pacific Power) employees has been outstanding," said Gleason. "Their efforts resulted in a very streamlined operation with attendant cost reductions and reduced customer prices . . . "

Pacific Telecom, the company's telecommunications unit, and NERCO, its mining and resource development subsidiary, also enjoyed record results in 1990, the latter despite soft natural gas and precious metals prices in 1990.

For 1991, Gleason said the company will continue working to build its core businesses and will continue to seek additional generation and transmission assets from various entities with excess capacity.

"We believe that this approach will benefit both customers and shareholders by eliminating siting, environmental, construction cost and financing uncertainties that are attendant in meeting our growing electric loads through the alternative of new plant construction."

PacifiCorp will hold its annual meeting this year in Salt Lake City. It is scheduled for Wednesday, May 15 at 1:30 p.m. in the Salt Palace.