Conservation and power-plant construction may be obvious ways of dealing with California's power crunch. But a Monrovia company is touting a less transparent remedy: fog.
Using the same technology that has clouded theme parks and disco floors, Mee Industries Inc. is using its man-made fog to help power-plant turbines run more efficiently in hot weather. The cooling vapor is like Geritol for flagging generators, enabling Glendale Water & Power, among other facilities, to boost the electrical output of its aging combustion turbines by as much as 20%, according to utility plant superintendent Larry Moorehouse.
"We can generate more power on a hot day than we could before," Moorehouse said. "Given recent prices . . . every megawatt counts."
Some of the biggest names in electricity have purchased Mee Industries fogging systems, including the Tennessee Valley Authority, Duke Energy and Florida Power & Light. It's a sign of the times in an industry looking to squeeze every last kilowatt out of existing plants while supplies remain tight and electricity prices soar. It also marks the rebirth of Mee Industries, a family-owned company once mired in bankruptcy proceedings that has bounced back to become the biggest name in power-plant fog.
"We created this market," said Thomas Mee III, chief executive of Mee Industries. "Fogging is [a] cheap, clean, easy and fast" way to generate more power.
At first blush, a company peddling fog as a way to create more kilowatts might seem suspect. But fogging systems are based on some fairly basic science: Cool air is denser than hot air.
That small fact is a big deal to power producers that use combustion turbines to generate electricity. Also known as gas turbines, these machines burn compressed air and natural gas or some other fuel in a combustion chamber to produce super-heated gas to power the blades of a turbine.
The output of a combustion turbine depends on the mass flow of air moving through it. So on sweltering days, when the ambient air is less dense, the amount of electricity produced can drop precipitously, according to Midwest energy consultant Dharam Punwani.
The result is that combustion turbine operators have less energy to sell in the dog days of summer just as demand soars. "In a hot environment, your output can easily go down by as much as 35%," said Punwani, head of Naperville, Ill.-based Avalon Consulting Inc. "It's a significant problem," particularly in parts of the Southwest.
Performance can be improved by chilling the intake air flowing into combustion turbines, using evaporating water, fog or refrigeration. Some of this technology has been around for decades. But Punwani says it took industry deregulation, soaring natural gas prices and rising demand for electricity over the last few years to motivate generators to begin installing so-called "inlet cooling" systems to wring more production out of their turbines.
That has been a boon to a host of small companies selling such technology. Among them is privately held Mee Industries, which has seen its sales nearly quintuple over the last five years to $25 million in 2000. Company officials say its technology improves the output of combustion turbines by 10% to 20%. They estimate the fogging systems have added 1,800 megawatts to the nation's electricity supply, enough to power about 1.4 million homes.
Conceptually, the Mee Industries system is pretty simple. Demineralized water is pumped under high pressure through hundreds of 1-inch stainless-steel nozzles, strung in a web across the air duct feeding a turbine's compressor. Tiny openings in each nozzle shoot an ultra-fine jet of water against a metal pin, creating a shower of droplets much like the spray you get by putting your thumb over the flow from a garden hose.
The difference is in the droplet size. Each nozzle creates billions of drops so tiny--less than one-tenth the width of a human hair--that they evaporate almost instantly, cooling the intake air by as much as 30 degrees without drenching it.
That's important to power-plant operators, a notoriously conservative bunch who don't want to take a chance on fouling the guts of their multimillion-dollar machines.
Gas turbines "are prima donnas that are extremely sensitive to variations in temperature and humidity," said Steve Ingistov, principal engineer for Watson Cogeneration Co. in Carson, which has installed Mee Industries foggers on four of its turbines. "The Mee system doesn't use much water . . . yet it's extremely effective. That's what's so great about it."
Power-plant operators also like the price. Costing from $50,000 to $200,000 depending on the size of the turbine, Mee Industries fogging systems deliver extra power for $10 to $20 a kilowatt, according to company officials. That compares with $400 to $800 a kilowatt to build a new power plant.