It would mean a faster and greener ride, and electrifying GO Transit’s rail system may even cost less than previous estimates suggested.

But don’t look for GO to electrify any of its lines in time for the 2015 Pan Am Games — and that includes the run that will run from the airport to Union Station.

It’s unlikely there would be time to electrify the airport link service before it opens that spring, said Karen Pitre, project director of a $4 million GO electrification study that was slated to be complete next month.

Metrolinx is already shopping for Tier 4 diesel trains for the air-rail link.

Electric locomotives that could pull 10 bi-level coaches make the most sense for GO’s commuter service, which will run more frequently in the future, said Pitre.

Although GO has already done several electrification studies, this is the first to look at the entire 509-kilometre rail network. It is also the first to separate out the costs of electrification from the incremental costs of improving and maintaining the GO system.

“The cost to electrify the whole system will be less than it has been conveyed previously because there tended to be a mixing of those numbers,” said Pitre, who wouldn’t provide any hint of the cost estimates before the study is released publicly, most likely in January.

The study looks at six electrification options and the environmental and ridership impact for each.

A 2001 study put the cost of electrifying the Lakeshore line between Hamilton and Oshawa at about $300 million. GO officials have estimated that electrifying the entire network would cost between $1 billion and $2 billion.

It’s already clear that electrifying entire GO lines makes more sense than converting individual sections of track, said Pitre.

“The previous studies have shown (electrification) can work. The question is — how big are the benefits? There’ll be a debate about that,” said Pitre.

Electric trains emit fewer harmful pollutants than diesel engines and can speed trip times, potentially shaving up to 12 minutes off a Georgetown trip and seven minutes off a journey to Hamilton.

But electric trains would still be subject to constraints that limit GO service now, including competing freight traffic, speed restrictions and limited platforms at Union Station.

Meantime, Ontario NDP leader Andrea Horwath has called on the Liberal government to stop Metrolinx from buying American-made Japanese diesel trains.

Toronto’s Clean Train Coalition is expected to demonstrate Tuesday at a Metrolinx board meeting. It says diesel trains carrying the estimated ridership of 5,000 passengers a day will actually pollute more than if those passengers drove to the airport.

Transportation Minister Kathleen Wynne told the Legislature that the Metrolinx procurement of Sumitomo trains, part of an order being placed by California, has not been finalized.