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THE MOUNTAINEER By Brian Mazza Old Ebenezer Scrooge was a miser with Bob Cratchit's coal scuttle as he penny pinched on heating costs, but the bucket of coal looks pretty good these days against the rising cost of both natural gas and electricity. Greenhouse operators are among the hardest hit with rising heating costs as they try to balance their ability to harvest a late crop or start earlier in the year, with the price of the energy needed. Bob Aasman Jr. of Hilltop Berry Farm had been trying to cope with the rising cost of natural gas, but he took action, turning to an Alberta-built coal-fired boiler for his greenhouse. He shut down his greenhouse operation last month, a bit earlier than normal to avoid the rising cost of natural gas, and began the process of refitting the building with heating pipes and the installation of the boiler. They started looking at alternatives last May or June and settled on an All Canadian Boiler built by Nova Metal Tech in Sherwood Park. Aasman said that the 2.3 million BTU system is enough to heat the existing greenhouse as well as having capacity to heat another bay, his shop and possibly even their home. The system is a fairly simple one, which will not only be less to run than a natural gas furnace, but he expects to save on electricity, too. Coal is loaded from a bin by auger into a hopper next to the burner. The amount of heat required to keep the system at 86 degrees C is controlled by a small DC motor which turns a small auger that feeds coal into the burner. The more heat required, the faster the auger turns. Coal is burned on a slotted plate at the bottom of the burner, with the fresh coal pushed up through the centre hole. From there it spills onto the plate and is burned. The gases rise to the next chamber where there is a secondary burn. That generates more heat while also reducing the amount of emissions. The hot water tank sits above the two burning chambers. It is from here that water is curculated into the pipe system used to heat the greenhouse. Warm pipes resting just above the floor of the greenhouse provide a radiant heat in the building. A small electronic device takes temperature readings of the water in the system and the air in the greenhouse and controls a special valve which acts to balance hot and cold water circulated in the system. The intent is to keep the greenhouse above 19 degrees, and it kicks in when the temperature falls below 21 degrees. The system allows a split in warming between the east side and west side of the greenhouse since the morning sun can cause the east side to warm up more quickly. The same situation does not occur at sunset. Electrical use will also be down since the amount of equipment needed to be powered is less. The natural gas system used forced air furnaces and there were fans operating in the greenhouse to ensure the heat was circulated. The new system required two pumps to circulate the water and a converted DC current to operate the coal feed system, as well as a small amount to operate the controller and sensors. Aasman estimates that he drops from 15 hp in motor power with natural gas to just four horsepower with this system, reducing power consumption at a time electricity rates are under upward pressure. Stoker coal is purchased from Dodd's Coal Mining Co. in Ryley, Alberta, southeast of Edmonton, and Aasman figures that one B-train load will last about a month, costing just a little over $1,300 to purchase. Transportation is another $700 when his cousin Harry Brouwer loads up at the mine on a return trip with his truck, making deliveries when timing is convenient. At a moment, supply is an issue. The full B-train truck load filled the one bin to within two feet of the top, said Aasman, meaning that he would need to wait until it is nearly empty before accepting a new shipment. He will address this by erecting a second bin. Coal compares very will to natural gas at the moment. At between $1,300 and $1,400 to heat the structures for a cold winter month, it is a fraction of what natural gas would cost. "We were paying that much in the summer", he said. "In 1995, we burnt $4,500 in gas and last year spent $12,000," he explained. "This year will be pretty close to $20,000". As natural gas spot market prices spike into the $10 per gigajoule range, he anticipates his gas costs would be in the $40,000 to $50,000 range. "We would go broke." Replacing the natural gas system with the coal fired boiler is estimated to cost between $50 and $60 thousand. As Hilltop Berry Farm establishes itself as a regular customer of the mining company for stoker coal, the price will also drop a bit, he has been told. A greenhouse in Gull Lake began operating with a similar coal fired system in September, and Aasman said the operator tested it for emissions and found them comparable to a natural gas system. The other residue, the ash, will be spread on the land as fertilizer, with Aasman noting it is high in potassium. He will also spread a bit around his cattle waterer in winter as grit to keep the ground from being slippery. The farm's greenhouse produces tomatoes and cucumbers for sale at market prices. It usually operates to the end of November and establishing the new crop begins in January. Work is proceeding quickly on the new system and Aasman hopes to fire up the boiler and begin operations in January. While concerned with the price of natural gas, up until now, Aasman has praise for Rupert Murphy, manager of the Rocky Gas Co-op, his supplier. He said that Murphy kept him well informed about the trends with natural gas prices and advised him to seek alternatives.
Trevelles Contracting Ltd. RR#2, Site 3, Box 9, Kingman, AB T0B 2M0 |