It's the $250 million question and Austin city leaders are thinking about it carefully.

It’s a proposed solar array plant, and some city leaders say it could play a big role in meeting Austin's future energy demands.

“It is a huge project,” Austin City Council Member Lee Leffingwell said. “It’s a lot of money.”

Even with the big price tag, some believe it’s a necessity.

“Solar has to be part of our renewable energy portfolio,” Leffingwell said.

The future of the largest solar power plant in the country is now in the hands of the city council.

“I think that we’re all going to come together on this because this is where the future is, both environmentally and economically in Austin,” City Council Member Brewster McCracken said.

If built, the plant would cost $10 million per year for the next 25 years. It would be built on city-owned property near the town of Webberville.

Gemini Solar Development, a California-based http://www.geminisolar.com/ company would own the plant, but the City of Austin would be the only entity using it.

Each year, it would produce enough energy to power about 5,000 homes.

According to Austin Energy , the average customer would see an increase of about 60 cents per month on their electric bill. The rest of the money would come from customers participating in the Green Choice program.

Many environmentalists are behind the solar power plant.

“I support this project,” environmental activist Paul Robbins said. “I believe this is a good move.”

Legally, the city does not have to say how much it is paying per unit of power.

Robbins said solar power is more expensive, but during peak energy usage, solar power is cheaper than current peak power generators.

“These generators are basically operating with expensive fuel, in the least efficient manner possible,” he said. “Consequently, they’re way up there in price.”

The city postponed the vote after some of Austin's largest companies were worried their electrical bills would increase.

The city will spend the next two weeks crunching the numbers. The solar plant topic will be back in front of council Feb. 12.