When last August's blackout gripped a big swath of the eastern United States, investors snapped up shares of firms involved in making fuel cells, providing backup power systems or improving the reliability of electrical networks.

The stocks surged immediately after the blackout hit, as the market banked on a rapid spending increase by government and private institutions to try to ensure a continuous supply of power.

For months, those shares maintained and even built on those gains. But now, as the blackout's anniversary approaches, almost all have given up that advance, and many are even below their pre- blackout levels.

To some market observers, it's no surprise: A similar pattern took place after the Sept. 11 terrorist attacks, with high-tech security stocks seeing a substantial rally, only to surrender them within two years as reality failed to meet expectations.

Even though the power sector has fallen back, several analysts remain hopeful about its prospects.

Although firms have separate issues, RBC Capital Markets analyst Jarett Carson said their fortunes have largely shifted with the broader market.

He said their runup predated the blackout. "The big turn started with the Nasdaq moveup in March 2003," he noted, and they have been pulled down with the rest of the market this year.

Fuel-cell and other earlier-stage companies tend to be more volatile than most.

"These are the ones that theoretically move the most on the upside, but the more speculative names are more likely to be hurt in a retreating market when people seek safety," Carson said.

The massive influx in spending to overhaul and back up the system has not materialized.

"Here we are a year later, there's no energy bill," Carson said. "There's been some movement, but no finalization of any mandatory electricity grid reliability law."

John Quealy, an analyst at Adams Harkness Inc., said the spending that has occurred has not been an all-out push for an overhaul, "not the type that government and industry truly need to put forth to fully rectify the situation."

"I think the spending was directed toward current solutions, to 'patch the grid,' where it failed," he said.

But, these analysts said, some companies have sound prospects nonetheless.

Quealy divides the stocks into two types: those that make fuel cells and other developing technology, and more mature companies providing backup energy, often called uninterruptible power-supply products, known as UPS systems.

Fuel-cell companies, in particular FuelCell Energy Inc. and Plug Power Inc., saw their shares easily more than double to post- blackout peaks from their closes the day before the blackout.

The UPS companies, namely C&D Technologies Inc. and American Power Conversion Corp., didn't experience as dramatic a runup, although they were up 46 percent and 69 percent, respectively, at their peaks.

Carson considers Plug Power more expensive, on an enterprise value basis, than FuelCell, which he calls "a clear leader" in the industry.

Quealy also prefers FuelCell, which he recently upgraded to "buy." Neither analyst owns shares in either company.

Those companies, Quealy said, would benefit from sustained high energy costs to energize the search for alternatives; continued inadequacy of the electric grid; and increased concerns about reliability and security, which would motivate more institutions to seek energy independence.

Fuel-cell firms have displayed growth, but it can be uneven.

"These are big projects--you're talking six- to nine-month lead times," Carson said, particularly for FuelCell. "The key is to continue to build the pipeline of opportunity."

"These are solutions five and 10 years down the road," Quealy said.

Quealy said rising commodity prices, particularly for lead used in batteries, have hurt UPS system companies, but their business has been "very robust" in the past 12 months.

"The demand for UPS systems has been quite strong" across the industry, he said. "The drivers continue to be very favorable for UPS companies."

Part of the impetus, he said, is that the blackout jolted customers into realizing just how vulnerable they are.

"It certainly brought home a lot of issues in terms of the world we live in is now 24-7," Quealy said.