As she sat at a small sunlit table by her apartment window, near the wheelchair and oxygen tank in the corner, Leona Morgan ticked off her monthly spending list.

Rent: $550. Groceries: $300. Medicine for anemia, a heart condition and other ailments: $50 beyond what's covered by government health programs. Electric bill: $93.87 in August.

"My income just barely covers what I have to spend," said Morgan, a sprightly, bone-thin 86-year-old, contemplating the possibility of soaring electric bills. "If my bills go up any more, all I can tell them is, 'I don't have any more to give you.' "

That is a predicament advocates fear an increasing number of low-income and elderly people will soon face in Austin. The city-owned electric provider, Austin Energy, expects bills to rise substantially in coming years, partially because of an aggressive plan to purchase more wind, solar and wood-waste energy and wean the city off fossil fuels, which contribute to global warming.

But Austin Energy cannot say how much bills will rise, mirroring worldwide uncertainty about energy costs in the coming years.

"We help a lot of people who can barely afford to keep the lights on now," said Ron Walker, chancellor for the Catholic Diocese of Austin, which calculates electric bills could rise 50 percent in the next five years. "Some of our parishes and schools work on a shoestring budget. The vagueness we've received about bottom-line effects on bills has left us with a lot of concerns."

Austin Energy officials have began seeking out nonprofits to discuss what's coming and already have some programs in place to help low-income customers. Roger Duncan, the utility's general manager, has also indefinitely postponed sending Austin Energy's carbon-reduction plan to the City Council for a vote, and he has scheduled a summit for Oct. 2 for advocates and utility officials to discuss how to help people with low incomes deal with the new costs.

"We've heard a lot from the city's large industrial customers, we've heard a lot from the environmental community, and now we're starting to hear from advocates" for the poor, Duncan said. "That's great. We need to be concerned about the needs of our residential customers, particularly the lower-income ones."

Last month, Austin Energy proposed adding even more wind and solar energy than is called for in the city's already ambitious Climate Protection Plan, which was passed with great fanfare in 2007. That plan committed Austin to getting 30 percent of its electricity from renewable sources by 2020, up from 12 percent now. But Austin Energy now says the city should shoot for 35 percent by 2020.

The utility originally estimated its new plan would raise monthly electric bills 22 percent by 2020. But Duncan and consultants hired by the city acknowledge that's just a best guess and that possibilities vary widely, meaning bills could be significantly higher.

There are also other costs on the horizon that concern the diocese and other nonprofits.

Austin Energy is planning to add a new fee next year to pay for transmission lines for wind energy generated in West Texas. Austin must pay 4 percent of the estimated $5 billion cost. The fee would start at about 60 cents a month and rise for several years.

But the big change will come in 2012 when the city will probably raise rates, although it can't say by how much. Duncan said Austin Energy must change the rate structure by then or start losing money.

"We could forecast a range of bill impacts for customers, but it would be so huge it would be meaningless," Duncan said.

Electricity prices are expected to soar in coming years because of increased worldwide demand for oil and natural gas. The federal government is also expected to create a cap on carbon emissions in the United States, which would make coal more expensive.

Meanwhile, the price of solar power is dropping, and wind is already considered one of the cheapest forms of power. But an Austin Energy program that sells wind power to customers who want to buy it now costs more than standard electricity. And wind and solar generate electricity only during parts of the day, and there is no proven way to store industrial amounts of that energy for later.

Against this backdrop, the city has held numerous public meetings during the past year about its carbon-reduction plan. Those meetings, however, were attended mainly by environmental activists, energy wonks and representatives of big businesses.

When Walker and other diocese officials met with Austin Energy a few weeks ago, they came away "stunned" at what the changes could mean, Walker said. "My head was swimming," Walker said. "I just don't think people are really aware of all this."

Diocese leaders met two weeks ago to share their concerns with state Rep. Elliott Naishtat, D-Austin. In an interview, he said that "combating global warming is necessary ... but it is incumbent on Austin Energy to make sure we don't end up balancing the green-energy budget on the backs of the poor."

Austin Energy now has several programs intended to help people with low incomes. One provides up to $1,500 for energy-efficiency improvements such as weather stripping, added insulation and minor repairs. Customers on government-aid programs such as Medicare are also eligible for a standard $6-a-month electric fee reduction, along with water, wastewater and street-maintenance fee reductions that could add up to as much as $40 on a total monthly utility bill. But Austin Energy acknowledges that not everyone is getting that benefit because the utility relies on other agencies to tell it who is eligible.

Morgan, for instance, was not getting that benefit despite being enrolled in Medicare.

With new costs on the horizon, Walker said the diocese is grappling with conflicting priorities.

The Catholic Church has committed itself to environmental causes. But Walker said that an average of 125 people a month came to Catholic Charities of Central Texas this summer for assistance on utility bills, and the average request was for between $200 and $400. Meanwhile, he said, St. Vincent de Paul, a church-sponsored outreach and aid program, wrote $425,000 in checks in 2008 to Austin Energy for utility assistance for low-income families.

In August, Travis County awarded 144 utility-assistance grants totaling $13,568.

A few nonprofits have already joined a makeshift coalition the diocese has formed to address the rising energy costs.

"We're talking about people who don't have things they can cut from their budgets," said Dan Pruett, executive director of Austin-area Meals on Wheels, which delivers lunches and dinners to about 4,000 homes a day.

"Austin Energy may have a great plan," Pruett said. "But we need to make sure we understand what rates going up will mean for people living in poverty in this community."

Sitting in her cramped apartment in East Austin, Morgan contemplated higher utility bills and concluded she would likely have to request setting up a payment plan that would allow her to pay back large bills over time. But she said she still might not be able to catch up.

"I have a heart problem," she said. "The doctor said my heart was beating too fast, and he said I can't have any more stress."

mtoohey@statesman.com; 445-3673

Energy costs rising

Austin Energy expects electricity costs to increase for a number of reasons, including a proposed plan to add more wind and solar power, the cost of paying for transmission lines to bring wind energy from West Texas and a new rate structure the utility expects to put in place around 2012. But the utility cannot say how much these changes will raise bills.

Today and in 2020

Where Austin Energy now gets its electricity, and where it proposes to by 2020:

As of today:

• Coal:32 percent
• Nuclear:25 percent
• Open market: 15 percent
• Wind: 12 percent
• Natural gas: 11 percent
• Purchase-power agreements: 4 percent
• Miscellaneous: 1 percent
• Solar: negligible

Proposal for 2020

• Wind: 26 percent
• Coal: 23 percent
• Nuclear: 22 percent
• Natural gas: 10 percent
• Open market: 9 percent
• Wood waste: 7 percent
• Solar: 3 percent

Source: Austin Energy