But plans to fund new transmission lines often become bogged down by political and even environmental opposition that delay work and cause funding shortfalls. Albany-based Conjunction LLC, for instance, announced plans in 2003 to invest approximately $700 million to bring 2,300 megawatts of surplus electricity from Canada to downstate New York. 

This would have been enough to replace Indian Point's 2,160 megawatts of electricity.

But environmental groups, including opponents to Indian Point, criticized the company's initial plan to string a power line on towers lined along the Hudson River. They dropped their opposition when Conjunction LLC modified its plans to instead run a 135-mile transmission line underground along the New York Thruway. 

But by then major investors had pulled out of the project and killed its prospects.

Energy Efficiency is Especially Difficult

Cutting electricity demand as a way to reduce dependence on Indian Point is a particularly difficult challenge, said Audin of Energywiz. 

"As a general rule, we are happy if we can keep a facility's peak demand and usage stable or reduce it slightly through energy efficiency upgrades," he said.

Just countering the approximately 1 percent per year load growth in the New York City area would require cutting demand by more than 100 megawatts per year, he said.

"Even with hefty rebates, that has only rarely occurred."

In the meantime, New York State is experimenting with a variety of energy efficiency programs to lower energy consumption. This summer it plans to reduce over 2,000 megawatts during peak periods through financial incentives and other consumer-oriented programs, a reduction that NYISO has already factored into its calculations of current electrical needs.

The recession helped bring energy use below pre-recession levels, according to NYISO calculations.  But usage in New York City completely recovered in 2010, and is expected to increase as economic growth returns.

Boosting electricity prices, a highly unpopular measure, could also cut demand. According to Audin's figures, cutting usage by 1 percent requires a 10 percent price hike, while reducing usage by 10 percent would require a near doubling of price.

When this occurred during Gov. Gray Davis's administration in California he was recalled and replaced by Arnold Schwarzenegger. 

For his part, Gov. Andrew Cuomo, a staunch opponent of Indian Point, who has recently heightened his opposition to the facility, admitted at a recent news conference that the state has no viable substitutes "at this time."

However, "could you have replacement power for Indian Point?" he asked. "Yes."

Monday: Part 3, What would be the economic costs of an Indian Point shutdown to Westchester County and New York City?