Nevada is less vulnerable than the East Coast to a huge power failure, but would not escape a widespread outage in the West, the head of the state's Public Utilities Commission said Tuesday.
"We can take comfort that we have a newer system, we can take comfort that we have an adequate system," Don Soderberg said.
"But I think the concern at the commission today is that if the system works exactly as it's planned, does it create another problem?
"A major disturbance in the West would create two islands, one in northern Nevada and one in southern Nevada, and then you'd have to rely on the generation that you have in your area."
Since Nevada generates only about half the power it uses, the rest has to be bought from suppliers outside the state.
"If we created an island in southern Nevada, our loose calculation is we'd be almost 1,200 megawatts short at peak," he said.
A megawatt is enough electricity for about 600 homes.
During last month's intense hot spell, Nevada Power Co. delivered a record 4,808 megawatts to its 680,000 customers in southern Nevada.
In Reno, where Sierra Pacific Power Co. delivered a record 1,620 megawatts, Soderberg said the utility would fall about 570 megawatts short of its peak capacity without importing power. Sierra Pacific has 323,000 customers.
Using last month's peak loads and Soderberg's estimates, the power companies would fall about 35 percent short of supplying Reno's electrical needs, and one of every four customers in southern Nevada could be without power.
"If we can't import for an extended period of time, we're going to have to have what they call in California rolling blackouts to make up the difference."
Earlier this month power failures darkened parts of eight states from Ohio to New York, stretched into Canada and left 50 million people in the dark.
Soderberg was joined at Tuesday's news conference by Walt Higgins, president and CEO of Sierra Pacific Resources, the parent of Nevada's two principal electrical utilities.
Both stressed the need for more generating plants and transmission lines in addition to those in use or nearing completion, a task Higgins conceded would be challenging because his company's grim financial situation.
Sierra Pacific Resources lost $172.4 million in its most recent quarter compared with a $41 million loss in the same quarter a year earlier. Its debt load has reduced its bond rate to high-interest junk status.
"Obviously the ability of the company to raise the needed capital to invest in transmission and generation is a challenge that we currently face," Higgins said.
A new transmission project in southern Nevada will cost $300 million, he said. Building a line linking Ely and Elko will require $100 million. Proposed power plants for southern Nevada will cost $250 million to $300 million each.
"Those kinds of capital improvement costs lie on top of the $250 million, plus or minus, a year that it takes to operate and hook the system up to new customers, "he said.
"We believe we're up to the challenge."