John N. Nemechek plays an unusual game every day with the citizens of the Washington area. He rises before most of us in the morning and monitors our activities as we get out of bed, turn up the heat and begin cooking breakfast.

Nemechek must stay one step ahead of everybody. As Washington Gas Light Co.'s "gas control engineer," he sits before banks of complex equipment in a control room and makes sure that enough natural gas is flowing through the 6,000-mile web of pipes under this area to keep civilization going for another day.

"When you get up in the morning and turn up the thermostat, the gas is right there at the volume and pressure you want," Nemechek says in his Greek accent. A 1960 immigrant, he is a short, intense man who speaks with equal enthusiasm about opportunities in America and about his job at WGL.

Winter is the preserve of the gas company just as summer, with its high air conditioning bills, belongs to the electric company. Two-thirds of America's homes are gas-heated, and WGL Chairman Paul E. Reichardt has been seen to smile with apparent pleasure while discussing sharp increases in his company's sales and profit figures caused by a difficult winter that meant hardship and expense for most people.

In a time of growing public consciousness about energy costs, the built-in contradiction between a utility company's need to seel energy and the nation's need to conserve it is coming into sharp focus.

In Washington, public concern has focused recently on WGL's proposed surcharge for customers who significantly cut their home gas consumption -- a proposal that federal energy officials oppose because they say it could discourage conservation and discriminate against people who switch to alternative energy sources.

WGL says the surcharge would apply only to those wo switch to another means of providing basic heat -- say a wood stove or heat pump -- while keeping their gas furnaces for standby use on the coldest days, when it is most expensive for the company to provide gas.

Arguments for and against the surcharge center on this expensive gas used on the coldest days, called "peaking gas." The control of peaking gas is largely what Nemechek's job is all about.

Here's how the system works as cold weather hits:

Nemechek arrives at the control room at 4 or 5 a.m., checks the 102 dials that show how much gas is being used by each Washington-area neighborhood, and studies the federal weather report plus a special weather report provided by WGL's own consultant.

As people begin getting up, the dials start to move. Nemechek plugs all his information into a mathematical formula, gets an idea of how much gas he'll need during the day, and calls WGL's four "peaking stations" -- in Rockville, Fairfax County, Prince George's County and the District -- to give the day's production orders.

This is a tricky business.

The peaking stations are storage areas where liquid propane and oil can be made into gas by a process of warming and vaporizing. Natural gas is also stored there.

The propance comes by railroad cars and can cost as much as $2.60 a therm -- a mearure of gas quantity -- as opposed to the roughly 18 cents a therm for pipeline gas supplied by two national distributors from oil fields in Texas and around the world.

The amount of cheap pipeline gas available must be preset three days before the gas is actually used, because that's how Texas. Each morning Nemechek calls ahead, and if the weather turns out to be colder than he guessed, the expensive peaking gas fills the gap.

A mistake can be costly. "It would be awful to overproduce (expensive peaking gas) and take less than we could from the pipeline," Nemechek said. "That would mean you take the expensive gas and leave the cheap gas on the table."

A mistake like that could cost as much as $100,000 in a single day, Nemechek said.

Unless such a mistake were detected, the cost would be passed through to customers under current ratemaking procedures. Company officers say they have no hard statistical information or dollar figures with which to rate Nemechek's performance in this regard.

Suppose Nemeckeck sees that the temperature is dropping rapidly and unexpectedly. People are turning up the gas. He knows he has 700 million cubic feet of pipeline gas available, but figures WGL's 545,000 customers in the area may use as much as 900,000 cubic feet that day.

"I scramble," he said. "I increase the rate to make at least 800 (million). I tell the stations, 'Be able to produce an additional so much.' You're fighting a battle, a constant battle. You assess the situation hour by hour. You sleep and eat here."

Nemechek orders only 100,000 additional cubic feet of peaking gas even rhough he thinks twice that may be needed because any overestimate can be so expensive. If the temperature does continue dropping, he can always order more.

With the weather bringing surprises, Nemecheck is constantly on the phone and telex to his weather specialists, monitoring the dials -- even glancing out the window at the flat Virginia landscape looking for weather clues.

"If we have a cloudy day the temperature is more level. If it's a clear sky, the temperature drops overnight. I'm taking educated guesses...

"There are other factors -- wind, sunshine and so on. And nonmaterial factors, such as people look outside and see it snowing and put up their thermostats even though it may be warmer because snow acts as an insulation...

"Christmas and New Year's day are very interesting, and our mathematical estimating system never works. People with fireplaces who never use them use them on those days.... On turkey day (Thanksgiving), people use a lot of gas for cooking. That's not serious, but you have to recognize it."

Nemechek said a Saturday when everyone stays home to watch a televised game may need a lot of gas, while a Saturday before Chtistmas when everyone is out shopping may need very little -- all factors that he has to plan for.

Although the peaking gas is tremendously expensive, the area uses relatively little of it. While a single LNG tanker from Algeria may carry enough gas to hear the entire Washington area for a year, the Rockville peaking station has enough reserves to do that job for only a few hours should pipeline gas be cut off entirely.

The simple physical limitations of storing and handling gas add to all these problems. Gas stored in rock formations, for example, can seep out of the microscopic pores of the rock only at certain rate. So while WGL has enormous quantities of gas stored this way in West Virginia, it cannot be tapped at will.

And the peaing stations are limited mechanically to producing gas at a relatively slow rate. They are designed to "add on" to pipeline supplies druing critical times rather than to supply the whole metropolitan area in case of a cutoff of the main pipeline supplies.

"Customers with dual-fuel heating systems use gas only on cold days, and the gas is expensive," the company explained in a newspaper advertisement defending its proposed surcharge. "If they pay the regular rate for gas while burning only the expensive 'cold-weather' gas, they won't be paying what it costs, and this will inevitably drive up the average price everyone pays."

Regardless of how the local regulatory commissions decide on the proposal, Nemecheck will be getting up early every cold morning to supply us with gas -- and loving every minute of it. "I appreciate this country because it's the only country in the world where you can work and become something," he said.