HOUSTON, Jan. 21 — Conoco Global Power (UK) Ltd., a unit of Conoco Inc., Houston, Monday said it will build a 730 Mw cogeneration plant next to its Humber refinery in the UK.

Construction of the combined heat and power (CHP) plant is expected to begin immediately with completion projected by 2004. The company didn’t release a cost estimate.

The announcement comes at a time electricity prices are falling in the UK market. Earlier this month, TXU Europe, a unit of TXU Corp., Dallas, Tex., said it would shut nearly a fifth of its UK coal-fired generation at the end of March due to overcapacity and falling wholesale prices.

The Conoco facility will supply steam and electricity to the 186,000 b/d Humber refinery, steam to a neighboring refinery, and electricity to the National Grid. It also will have the capacity to provide an alternative source power and heat to other companies on the South Humber Bank, the company said.

“The location and energy needs of Conoco’s Humber refinery present a unique opportunity to construct a world-class CHP plant in the UK,” said Managing Director Jeff Tetlow. CHP plants use natural gas-fired combustion turbines to generate electricity. Steam produced from the exhaust energy of the turbines is then utilized to generate additional electricity and heat for industrial use.

The plant will reduce atmospheric emissions of carbon dioxide, sulphur oxides, and nitrogen oxides, compared with power generation by conventional means. The plant will also make better use of certain by-products of the refining processes; reduce surplus gas flaring; and conserve water resources by using existing waste water for cooling, rather than fresh water.

Conoco and Phillips Petroleum Co., Bartlesville, Okla., agreed to a $35 billion merger Nov. 19., creating the third-largest integrated US energy company based on market capitalization and oil and gas reserves and production. The companies expect to complete the merger in the second half of this year.