Groton — Pfizer Inc.'s new efficient 5.6 megawatt, multimillion-dollar fuel-cell power plants were unveiled Thursday as officials hailed their reliability and low impact on the environment. 

"We're working together to make sure the future of this site is strong," Gov. Dannel P. Malloy said after cutting the ribbon marking the power plant's official opening.

John Burkhardt, the new site director for Pfizer's Connecticut laboratories, said the two side-by-side fuel-cell plants came out of talks that his predecessor, Rod MacKenzie, had with the New York-based corporation's chief financial officer, Frank D'Amelio. Asked about any concerns he had, MacKenzie told D'Amelio about occasional power interruptions the Groton campus had experienced that put some of its experiments at risk, Burkhardt said.

"We needed to self-generate," said Sue Zimbelmann, chief of global operations for Pfizer.

So Pfizer asked Danbury-based FuelCell Energy to design and install the plants on its north campus off Eastern Point Road. North Stonington-based AZ Corp. worked on the plants' construction, which took about five months.

The plants include about 1,500 tons of concrete and rebar and a quarter mile of piping.

Mike Lallier, site operations manager, said most energy plants are about 35 percent efficient, while the fuel-cell equivalent is 47 percent efficient on the electrical side. But when steam generation that is recaptured by the plants is taken into account, the operation is nearly 90 percent efficient, he said.

"This allows us to eliminate any delays in our science," Lallier said.

It also allows Connecticut to tout its ability in the fuel-cell field.

"We are a hot spot for that research and development," Malloy said.

U.S. Sen. Richard Blumenthal, D-Conn., who did not speak at the event, said in a separate interview that he has been touting the state as the capital of fuel-cell research and development nationwide.

He said he would be holding up the Pfizer fuel-cell plants as a shining example of energy efficiency and renewable energy as he attempts to talk colleagues into passing a tax credit for businesses that make similar conversions.

"I'm very hopeful we can get it done," he said.

Lallier said the new plants will provide anywhere between 25 percent and 50 percent of the Pfizer campus' power needs. The system will be used during normal operations in conjunction with power supplied by Groton Public Utilities as well as acting as a backup electricity supplier during emergencies.

Pfizer is not paying for plant construction directly. FuelCell Energy prefabricated the plants off-site and paid for installation in 1.5-acre parcel, Pfizer said, while the company pays a charge based on power use.

The fuel-cell company will manage the plants and control them off site from its Danbury headquarters. The plants are expected to cut more than 28,000 tons of greenhouse gas emissions annually, meshing with Pfizer's stated goal of reducing such pollutants 20 percent by 2020.

"It's basically a big D.C. battery," Lallier said during a tour of the site.

He said the only emissions are carbon dioxide and water. There are no flames involved in generating power, so the chances of the plants catching fire are extremely remote, he said.

"Our critical buildings are going to be supported by these facilities," Lallier said.

l.howard@theday.com