THE INCREASED interest in woodstoves in the past three or four years has fueled skyrocketing wood prices. Last year a cord of wood went for $80 to $100, this year prices are expected to reach $150 to $180.

(A "cord" measures 128 cubic feet arranged in a pile 8 feet long, 4 feet high and 4 feet wide.)

A factor in the exorbitant cost is the simple fact that the Washington area is not overly endowed with the natural resource. Between the two -- the prices and the shortage -- cutting back on energy costs won't be easy for Washingtonians this winter.

But Washingtonians are taking the situation in hand. Instead of pining away (pun intended) for wood, the residents of the capital city are slowly converting to coal or a combination of wood and coal to fuel their stoves this winter.

Coal is becoming cheaper than wood. As wood prices increase astronomically, coal stays at relatively low prices. One ton of coal goes for $100 while an equal amount of wood (two-thirds cords), goes for anywhere from $80 to $180, depending on the area you live in.

Coal, like oil, nuclear power and wood, is not the perfect fuel. It pollutes more than wood -- bituminous coal contains 2.5 percent sulfur as compared with .02 for wood. (When sulfur burns it converts to sulfur dioxide, which is the major villain in air pollution.) Coal produces more ashes than wood, which means more shoveling. Coal stoves are somewhat harder to light than wood. Once they're lit they stay lit longer than wood, but this in turn can lead to overheating.

Now for the good news. Coal is more efficient fuel than wood. In Jason Schneider's "Complete Guide to Woodburning Stoves," he writes that a pound of wood burns about 5,780 BTUs of available heat, while a pound of anthracite coal burned under the same conditions gives off about 11,000 BTUs per pound. (Anthracite coal is hard and burns better and cleaner than the softer bituminous coal. Anthracite is more difficult to light than bituminous.)

The same pound of coal will burn much longer than its wood counterpart. As a result, you don't have to tend a coal fire as often as you would a wood one. (Jason Schneider suggests once or twice a day.)

Sure coal is sold in chunks of similar size, it burns more evely than wood. This prevents heat surges and dying fires and also causes thermostatic controls to operate more efficiently.

Coal is a more compact fuel than wood. It takes up less storage space than wood logs. It can be stored indoors (and outdoors -- if it's anthracite coal and properly packaged) -- "nothing can hurt anthracite," says Leo Wells of Watkins Stoves. At Bill's Hardware in Arlington, their five-pound pags are made of polyethlene, a woven plastic that protects its contents from moisture. Unlike wood, coal does not need to be dried out before using, though indoor storage is especially nice for those cold blustery winter nights when the thought of going outside is enough to make you wish you still had your oil furnance.

Although coal is more polluting, the soot accumulations in the chimney, called creosote, are negligible compared to wood.

William Barse of the Energy Center at Tysons Corner says the best kind of coal to use is a low sulfate, slow-burning coal, "which is fairly accessible in this area, but it would be easier to buy," admits Barse, "if local deliveries were re-established as in the old days."

Here are some places to buy this black cubical fuel:

Bill's Hardware, 4756 Lee Highway in Arlington, sells 50-pound bags for $5.95. If you buy four or more each bag costs $4.95.(Owner Bill Ploskina says that plans are in making for a 40-pound bag that would be easier to carry.) Bill doesn't deliver.

F. L. Watkins Co. Inc., 5701 George N. Palmer Highway in Seat Pleasant, Md., is selling one ton of coal for $110. You can still buy the leftovers from last year's supply for $104.50 if you hurry.

D. L. Bromwell Inc., (in Rockville, Hyattsville, Falls Church and Alexandria) sells a 40-pound bag of anthracite coal for $5.50.

At the Energy Center, 8453-Q Tyco Rd., Tysons Corner, Va., 25-pound bags cost $2.75 a piece.

Fairfax Wood Stoves, 9784 Lee Highway in Fairfax, charges $5 for a 50-pound bag, but their shipment doesn't come in until Sept. 15.

La Plata Mills, Kent Ave. in La Plata, Md., charge $90 per ton, if you pick the coal up yourself; and $100 per ton if they deliver (which they do within a 10-mile radius). They also sell 50-pound bags for $4.15. La Plata carries both small and large anthracite coal.

At Wire Hardware & Lumber, 22 Baltimore Rd. in Rockville, one ton of coal goes for about $94, up 10 dollars from last year.

Once you decide to use coal, or a combination of coal and wood, you'll need a coal scuttle -- (a bucket with a wide lip from which you pour coal into a fire) -- a coal grate and a shovel. Most of these items can be bought at any of the above, as well as at companies that sell wood and coal stoves.

"Coal isn't for everyone," Barse reminds us. "The type of fuel you use depends on your life style. Before turning to coal, or wood for that matter, you should consider whether you'll be home enough to tend to this new heating method. It takes a lot more time and effort than oil or electricity." h