The increasing cost of fuel - natural gas, oil and electricity - may make the heating bill of suburban Maryland residents as high or even higher than last winter.

Fuel costs already have risen 10 to 20 per cent since last fall and natural gas, which heats most area homes, could jump another 2.5 per cent if the Maryland Public Service Commission approves the rate increases requested in September by the Washington Gas Light Co. The majority of suburban Maryland homes and apartment buildings - more than 205,000 - are heated by natural gas.

Electric rates also may go up 7.6 per cent, the amount requested of the Public Service Commission last month. About 18,750 electrically heated homes in Montgomery and Prince George's counties use large quantities of electricity. Monthly electric bills also will continue to rise (and occasionally drop) as the price of fuel oil fluctuates, since most Potomac Electric Power Co. generators are oil-fired and fuel costs are passed on directly to consumers.

The National Weather Service predicts this winter will be colder than normal, though not quite the record cold of last winter, and the Old Farmer's Almanac and the Hagerstown Almanac - which have been prognosticating such things for 185 and 181 years respectively - also predict colder-than-normal weather and lots of snow in this area.

While the expected cold weather would mean high fuel bills, it is not expected to cause any fuel shortages this winter. Local fuel and utility companies say there are sufficient supplies of all heating fuels to carry the Washington area through even a severe winter, barring another Arab oil boycott.

Last winter's prolonged cold spell caused natural gas shortages in Virginia and around the nation - many schools and businesses in Northern Virginia were closed during the height of the shortage - and pipeline companies predicted early this summer that similar shortages could occur again this winter.

The Washington Gas Light Co. has substantially increased the amount of gas in underground storage since then, however, and foresees no shortages, although its 250 "interruptible" customers - large plants whose furnaces also can use fuel oil - could be forced to switch from gas to oil.

Natural gas currently is less expensive in Maryland than in the District, but slightly higher than in Northern Virginia, although the state utility commission is considering a 5 per cent rate increase there. A typical fall monthly gas bill for a Maryland family (for 125 therms) is $40.65 compared to $43.08 for a similar District of Columbia house and $39.51 for a Northern Virginia resident, according to the Washington Gas Light Co.

The price of natural gas for Maryland residents has risen 94 per cent in the past five years (it was $20.93 in 1972 for 125 therms), compared to a 116 per cent increase for District of Columbia residents and 85 per cent for Northern Virginia residents, according to the Gas Light Co.

Fuel oil and electricity both are significantly more expensive than gas as heating fuels, as can be seen from the accompanying formula for determining fuel costs prepared for The Post last fall by the Federal Energy Administration, predecessor of the new Department of Energy.

Fire wood, if it can be bought for less than $60 a cord and burned in an air-tight stove, is cheaper even than natural gas as a home heating fuel, as increasing numbers of homeowners are discovering. More than 10,000 woods stoves have been sold in the Washington area alone so far this year, and dealers say this fall they are selling stoves and fireplace heat-saving devices, like glass doors and air-circulating grates, faster than ever before.

Most stoves are attached to existing fireplaces and used to provide supplementary heat, enabling owners to keep expensive heating systems turned down or off. The glass doors and the steel-tubed grates, which force hot air into the room, are said to improve the efficiency of existing fireplaces.

Even fire wood has increased in price. Dealers here now are asking $60-$65 a cord, or more, for split hardwood, compared to $55 a cord last fall, and there are waiting lists at some dealers. Homeowners with a wood lot or access to free fire wood obviously have by far the cheapest fuel. And aside from solar heat, fire wood is considered one of the best fuels ecologically, since it is a constantly renewable resource. It also smells better when it burns.

The delights and benefits of wood burning have caused local governments here to warn residents about door-to-door fire wood salesmen and to declare most county and city parklands off-limits to would-be wood hunters.

COMPARISON OF HEATING COSTS

Formula for computing effective cost of heating fuels, prepared by Department of Energy: [A] over [B] x [C] = [X](TABLE) Fuel(COLUMN)Current(COLUMN)Last(COLUMN)Efficiency(COLUMN)BTU(COLUMN)Cost Per (COLUMN)(COLUMN)Cost(COLUMN)Year's(COLUMN)Factor(COLUMN)Conversion Million (COLUMN)(COLUMN)(COLUMN)Cost(COLUMN)of Furnace(COLUMN)Factor BTUs (COLUMN)[A](COLUMN)(COLUMN)[B](COLUMN)[C](COLUMN)[X] Natural Gas(COLUMN)$2.85(COLUMN)$2.40(COLUMN).7(COLUMN).976(COLUMN)$3.97 (COLUMN)Av. 1,000 cu. ft.(COLUMN)(COLUMN)(COLUMN)(COLUMN) Fuel Oil(COLUMN)48 cents gallons(COLUMN).41(COLUMN).6(COLUMN)7.14(COLUMN)$5.71 Wood(COLUMN)$65 cord(COLUMN)$55(COLUMN).6*(COLUMN).04(COLUMN)$4.33 (COLUMN)(COLUMN)(COLUMN).2**(COLUMN)(COLUMN) Electricity***(COLUMN)(COLUMN)(COLUMN)(COLUMN)(COLUMN) (VEPCO)(COLUMN)(COLUMN)(COLUMN)(COLUMN)(COLUMN) No. Virginia(COLUMN).03 cent/kilowatt(COLUMN).028(COLUMN)1(COLUMN)293.1(COLUMN)8.79 (PEPCO)(COLUMN)(COLUMN)(COLUMN)(COLUMN)(COLUMN) Maryland(COLUMN).037 cent/kilowatt(COLUMN).032(COLUMN)1(COLUMN)293.1(COLUMN)$10.84 District(COLUMN).036 cent/kilowatt(COLUMN).035(COLUMN)1(COLUMN)293.1(COLUMN)$10.55 No. Arlington(COLUMN).040 cent/kilowatt(COLUMN).035(COLUMN)1(COLUMN)293.1(COLUMN)$11.72(END TABLE)(FOOTNOTE)

* Wood Stoves

** Fireplaces

*** For electric baseboard heat. Electric heat pumps can reduce bills by as much as 30 per cent or more, manufacturers claim. (END FOOT)

Prince George's County prohibits removal of any wood from Maryland National Capital Park and Planning Commission lands within the county, while Montomgery County permits removal only of wood that park employees have cut into firewood lengths and left at the edge of the parks. The National Park Service has a $50 fine for a anyone caught taking wood or anything else from Rock Creek Park and other federal parkland here.

However, Maryland's Department of Natural Resources now permits cutting of firewood in many of its state forests, but only fallen trees in designated sections and only with a permit. Two state forests within 40 miles of Washington offer firewood virtually free - $1 permits entitle woodsmen to one pick-up truck load - with unlimited supplies of pine at Cedarville Forest near Waldorf and both soft and hardwoods at Doncaster Forest father along the peninsula. Permits for both forests are available weekdays at Cedarville Forest headquarters.

One of the main reasons heating bills have been rising is the increasing cost and dwindling supply of fossil fuels - oil and natural gas. Fuel oil costs 15 to 20 per cent more than it did last fall, which not only affects homeowners with oil furnaces (who now pay about 48 cents a gallon throughout the Washington area compared to 41 cents last fall), but boosts electric bills since fuel oil is the major fuel used by electric utilities and fuel prices increases automatically are passed on to consumers.

Most Northern Virginians pay less than Maryland and District residents for electricity partly because relatively cheap nuclear power and coal provide more than a third of the electricity for the Virginia Electric Power Co., and Virginia residents thus have had lower fuel-price increases passed on to them. The gap could widen since the Potomac Electric Power Co., which supplies D.C. and Maryland residents and a number of North Arlington residents, is asking for rate increases ranging from 7.6 to 21 per cent.

The North Arlington customers of Pepco with all-electric homes now pay an average 4 cents a kilowatt hour for their electricity - compared to about 3 cents a kilowatt for Vepco customers - and Pepco is asking for a rate boost of 21 per cent for its Virginia users. An all-electric Maryland home pays an average 3.7 cents a kilowatt; a similar District of Columbia home pays 3.6 cents, and Pepco's North Arlington customers pay an average 4 cents a kilowatt. All users pay higher rates for initial amounts of electricity, but the rate declines for large users such as those with all-electric homes.