The natural-gas-fired generating station, which will be the only significant source of power within Toronto's boundaries, is rising on the eastern waterfront, near the base of the Leslie Street Spit.
"We're on target for being ready June 1, 2008," says Portlands spokesperson Ted Gruetzner, trudging through the busy construction site.
The most prominent features of the project right now are the four stacks rising above the site.
Two are relatively stubby about 45 metres high while two are larger, at about 75 metres. All are dwarfed by the nearby stack of the now defunct Hearn generating station, which rises 225 metres.
The small stacks won't be used for long.
They're in place to vent the exhaust of two gas turbines that each drive 170-megawatt generators. Those units are slated to be test-fired in March, and to start commercial operation by the summer to feed Toronto's thirst for power.
Gas turbines are essentially jet engines powered by natural gas. But the turbines spew large volumes of hot gas out their exhausts heat that simply goes to waste.
Because Toronto needs power right away, for the first year of the turbines' operation, the plant will operate in this fashion.
But under construction at the same time is a network of pipes and equipment that, starting in 2009, will trap the exhaust gases and feed them into a heat exchanger.
There, the heat will produce steam to drive another generator, producing a further 210 megawatts.
The city's power supply is watched carefully by commercial property developers, for whom a reliable power supply is essential.
Construction of the Portlands plant provided big building operators with needed assurance, said Chuck Stradling, executive vice-president of the Building Owners and Managers Association.
"I think there's a sense of relief among most of the downtown landlords that they shouldn't have a problem with power for the foreseeable future."
The relief is not shared by all.
Councillor Paula Fletcher, whose ward encompasses the plant, fears that emissions from the gas turbines will only add to air pollution in the surrounding neighbourhood.
She said backers of the $700 million plant assume that electricity demand will continue to rise. Instead, she said, why not go in the opposite direction?
Citizens should "ask, demand, beg, cajole and push" the province to spend an equal amount on conservation, demand management and renewable energy, she said.
Portlands Energy Centre, which is a joint partnership of Ontario Power Generation and the TransCanada energy company, is required to have a community liaison committee, but several of its members quit earlier this year.
One of them, Dennis Findlay, said he and the others who walked out wanted independent monitoring of the plant's emissions. They also wanted the plant designed to be as bird-friendly as possible.
Portlands officials weren't receptive, he said. "We felt we were being used as window dressing," and decided not to participate further.
Gruetzner said other community members have stayed with the committee and more will be recruited to fill the vacancies.
Fletcher said she's continuing to participate, but acknowledges that interest in the committee has gone "a bit dormant."
But she predicts the local community will pay more attention starting this summer.
"Once the plant starts operating, there'll be some pretty big interest."