The increasing cost of fuel - natural gas, oil, and electricity - may make the home heating bills of District residents as high as 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 10.3 per cent if the D.C. Public Service Commission approves the rate increase requested last July by the Washington Gas Light Co.

Electric rates also may go up an additional 16 per cent, the amount requested of the PSC last month by the Potomac Electric Power Co. There are about 3,700 all-electric homes, heated by electricity, in the District. Monthly electric bills will continue to rise (and occasionally drop) as the price of fuel oil fluctuates, because most pepo generators are oil-fired and fuel costs are passed on directly to consumers.

The National Weather Service's long-range forecast calls for a colder than normal winter, 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 the area.

Although the 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 are through even severe winter, barring another Arab oil boycott.

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

However, the Washington Gas Light Co. has substantially increased the amount of gas in underground storage since then 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 is more expensive in the District than it is in either suburban Maryland or Northern Virginia, with the average fall monthly bill for a District resident (using 125 therms) now $43.08 compared to $40.65 for a similar Maryland resident and $39.51 for a similar Northern Virginia resident, according to the Washington Gas Light Co.

The price of natural gas for most D.C. residents has risen 116 per cent since 1972 (when 125 therms cost $19.89), compared with a 94 per cent increase for Maryland customers and an 85 per cent increase for those in Northern Virginia, according to the Washington Gas Light Co., which operates separate divisions in each jurisdiction and must go before separate D.C., Maryland and Virginia commissions for rate increases.

Fuel oil and electricity 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 to the new Department of Energy.

Firewood, if it can be bought for less than $60 a cord and burned in an airtight stove, is cheaper even than natural gas as a home heating fuel, as increasing numbers of homeowners are discovering. More than 10,000 wood stoves have been sold in the Washington area so far this year, and dealers say they are selling stoves and other heat-saving devices, such as glass doors and air-circulating grates for fireplaces, 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 fireplace doors and steel-tubed grates, which force hot air into the room, are said to improve the efficiency of existing fireplaces.

However, even firewood has increased in price. Dealers here 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 or access to free fire wood obviously have by far the cheapest fuel. And aside from solar heat, firewood is considered one of the best fuels ecologically, since it is a constantly renewable resource. It also smells better than other fuels when it burns.

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

It is illegal to remove wood, or anything else, from federal parkland and from parks in most suburban areas.

Residents buying firewood are warned to beware of those peddling "ricks," "racks," or "face cords," which are meaningless terms. A good eyeball measure of a cord of wood is two four-foot high rows of two-foot logs stacked on a truck with an eight-foot wide flab-bed. However, since most trucks used by wood dealers are 7 1/2 feet wide, the rows should be higher or rounded to compensate.

One of the main reasons heating bills have been rising is the increasing cost and dwindling supply of fossil fuels - oil, coal and natural gas. Fuel oil costs 15 to 20 per cent more than it did lat 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 oil is the major fuel used by electric utilities and price 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 because Pepco is asking for a 16 per cent rate increase in the District, 7.6 in Maryland and 21 per cent for its North Arlington customers.

The North Arlington customers of Pepco with all-electric homes now pay about 4 cents a kilowatt hour for electricity, compared to about 3 cents a kilowatt for Vepco customers. An all-electric Maryland home pays an average 3.7 cents a kilowatt and a similar District home pays 3.6 cents.

All electricity users pay higher rates for initial amounts of electricity, but the rate declines for large users such as those with all-electric homes.