County commissioners were given an update Wednesday on a proposed biomass-fueled power plant in downtown Vancouver.Mark McCauley, the county’s general services manager, said a number of large, well-financed companies are interested in forming a partnership with the county to build and operate the plant.He said the county would pay about $210,000 per year for renewable energy, comparable to what it currently pays for natural gas. He said the county would save approximately $100,000 a year by cutting back its use of massive chiller units, which are part of the air conditioning system. In addition the county would charge $75,000 a year to the company to lease the land. Last summer, commissioners agreed to spend $225,000 from a federal energy block grant on studying the feasibility of a biomass boiler system (fueled by tree tops, limbs and the detritus of producing lumber) that would provide central heating, cooling and domestic hot water for five county buildings: the Public Service Center, courthouse, jail, 911 center and juvenile courthouse.No final decision has been made on whether to go ahead with the four- or five-story plant, but McCauley will ask the board on April 20 to decide whether the county should put out a formal request for a business partner. Commissioners plan to discuss the topic during a meeting with the Vancouver City Council on April 11.The city would have to approve a zone change and permits for the plant, which the county would like to put on the corner of West 13th and Harney streets, west of the Clark County Jail.