Provo-based Raser Technologies announced Thursday that it will partner with United Technologies Corp. to build its first three geothermal power plants.

Raser said it has agreed to buy up to 135 geothermal power systems from UTC Power, part of Connecticut-based United Technologies, which will generate about 30 megawatts of renewable electrical power.

"We believe these types of renewable energy-producing power plants will be a significant part of the U.S. power production portfolio in the future," Brent M. Cook, Raser's chief executive officer, said in a statement Thursday. "Accelerated development of domestic geothermal resources will produce electricity in an environmentally friendly way and contribute to energy independence."

The first 45 systems are expected to be delivered to the first plant site in the fourth quarter of 2007, the companies said. Raser has agreed to maintain the units once delivered.

Raser said it will make down payments to UTC Power and consideration for the technology development and field demonstration anticipated by Raser and UTC Power. Financial details of the agreements were not disclosed.

Martin Petersen, Raser's chief financial officer, said the plants will be built on property Raser has leased, though he did not disclose specific locations. Raser has leased properties in Utah and Nevada, he said.

Raser also has not disclosed the cost of building the plants, each of which is expected to generate about 10 megawatts of electricity. The three plants announced Thursday will be the company's first.

Cook declined to comment on how much the plants would cost. However, he said, the company expects that they will be funded by "tax monetizers."

"All of our tax monetizers are very large entities," he said, "capable of either funding directly or providing leveraged funding if they choose."

Petersen said a tax monetizer is a company or firm with which Raser has teamed up, which provides the capital required to build the plant. That enables it to utilize various incentives (primarily tax) the government offers to entities that build and operate renewable energy plants.

Work on the first of the three planned plants is targeted to start in May 2007, Cook said. Raser hopes to have it beginning commercial operation at the end of March 2008. All three are targeted to be operational by the end of 2008, he said.

The company is "in discussion" with an undisclosed number of parties regarding power purchase agreements, Cook said, though the company did not announce any deals on Thursday.