As the temperatures rose to 51 degrees here yesterday and electricity and oil were reported to be in ample supply, Northern Virginians attacked energy-conservation orders that have closed schools and cut back business hours in Virginia but not in the District of Columbia and suburban Maryland.

Legislators, business people and shoppers alike have become increasingly critical of the emergency order - issued Saturday by Gov Mills E. Godwin - that limits store hours to 40 hours a week until at least Feb. 13. The statewide order affects not only business heated by scarce natural gas but those that use oil and electricity.

"I think the order ought to be rescinded for those businesses heated by oil or electricity," Fairfax County Board Chairman John F. Herrity said.

The common theme in Northern Virginia was expressed by Rep. Herbert E. Harris (D), who represents southern Fairfax County and Alexandria: "People are very confused that these restrictions are applied in Virginia and nowhere else in the region. Businessmen are especially angry. It's hard to watch those cars drive over the Woodrow Wilson bridge taking the business into Maryland or the District."

Robert J. Parcelles, owner of Bob's Beef House and Bob's Diner Restaurant in Fairfax City, said the 40-hour restriction angers him because it does not save any more energy than turning down thermostats.

"The Governor can save energy without this extreme sacrifice from poor working people," Parcelles said. "I'm talking about people who depend on Friday's paycheck to buy Saturdays groceries."

Convened in joint session at the request of the Fairfax Board of Supervisors, four committees of the Metropolitan Washington Council of Governments yesterday unanimously adopted a resolution calling on the governors of Maryland and Virginia to give local jurisdictions here the power to deal with weather and energy crisis on a regional level, using COG to coordinate their actions.

At present, there are wide disparities in the way local governments have responded to the crisis.

Godwin imposed a 40-hour week for businesses and ordered school thermostats turned down to 55 degrees.Gov. Marvin Mandel has set on limitation on shop hours in Maryland and the state Public Service Commission has exempted schools from the "nonessential" category of natural gas customers who must lower their temperature to 55 degrees. In the District the Public Service Commission has authorized the Washington Gas Light Co. to curtail gas to nonessential customers but it did not adopt language recommended by the utility that would have requested "nonessential" customers to lower their thermostats to 55 degrees.

Mayor Washington last Saturday urged nonessential gas customers to put their thermostats at 65 degrees during business hours - the ceiling that President Carter asked all Americans to honor - and asked shops and other businesses to stay open no more than 48 hours weekly.

"The order is not being followed in the District," a Washington Gas Light spokewoman said.

In Virginia yesterday, Sen. Wiley F. Mitchell (R-Alex.) took the floor of the General Assembly to say: "I am perplexed that Virginia has a crisis while one does not exist in Maryland, the District of Columbia, Kentucky, Tennessee, or North Carolina."

Henry Zimmerman, an official of the Virginia Electric Power Co., told official that "Our fuel supplies are adequate to meet the expected demands throught the end of the heating season." Joseph Amato, president of the Oil Heating Institute, said, "As it stands right now, we see no immediate problem serving our customers 100 per cent of the time."

By contrast, the natural gas report given by WGL's president, Paul Reichardt, was pessimistic, not only for the rest of the winter but for some years to come.

Commenting on the newly-enacted U.S. emergency gas legislation, Reichardt said: "It won't give us one more cubic foot of gas. It just spreads the misery around . . . We're in for some belt-tightening for years to come."

He said the problem originates with the pipelines companies, which buy natural gas from producers at the wellhead and ship it across states to local untilities.

The pipelines, he said, have been unable to replenish their badly depleted storage fields, vast underground reservoirs necessary to maintain pressure in pipelines, which are as big as 40 inches in diameter.

Reichardt said Columbia Gas Transmission Corp., which supplies 85 per cent of WGL's gas, has seen its storage fields depleted to the level that normally is reached during the first week of April, after the heaviest demand of the heating season is over.

It was the pipelines' attempt to build up storage - and thus maintain pressure that would keep gas flowing - that led to the curtailments affecting WGL and Baltimore Gas & Electric Co. The curtailments have been extended twice, the second one continuing until 8 a.m. Wednesday.

Reichardt said of the crisis: "If the pipeline goes down the tube, we go with it . . . So all of us have to cooperate to keep the integrity of the system."