Column: An overview of perplexing energy prices
All of our energy is biological in origin – a bacterial fermentation of vegetation from millions of years that we dug up, or drilled, or whatever. Everything that can grow can be fuel, be it wood, corn, beans, oats, switch grass, bales of straw, you name it. It all grew for one reason – the sun.
Every second, the sun loses 400,000 tons of its mass, as high energy hydrogen atoms change through fusion into helium atoms, and the yield gets to us as sunlight. No, it won’t be gone soon. Various estimates say it’s got enough for another billion years. Point: part of that sun’s energy is in the biomass we burn.
Everyone with a propane (LP – liquefied petroleum) gas furnace has been pretty upset over its price increase. Five bucks a gallon for propane?? Who’d have ever thought it could reach that?
What happened? An extremely wet corn and bean crop – way, way more moisture to bake out of that grain than normal so it could be stored without spoiling – along with a pipeline that comes down from the shale fields in Canada that brings us propane that changed to oil.
And bam! Shortage!
About half of our propane comes from oil wells, and the other half comes from the refinement of oil into automobile gasoline. The big problem for any fuel that exists as a vapor at atmospheric pressure, like LP or natural gas, is storage. Natural gas remains a vapor as it is stuffed down into various old salt domes and salt mines and even into normal drinking water aquifers across the United States. It remains down there as a vapor until we bring it back up. There’s a lot of natural gas, but storage is always the challenge. It’s never quite where we need it.
Propane, however, is compressed and stored as a liquid. Some of our stored propane comes from Mentor, Minn., where in the ‘60s some business people bored into the earth, into bedrock, and mined out a cavern in which to store propane under pressure as a liquid. Propane turns into a liquid at more or less 70 psi, which is about twice that of the tires on your car. As a liquid, then, it comes to your tank at your home, then out of the tank as a vapor, which your furnace can burn.
Information about the Mentor mine is scarce, because the Homeland Security folks are worried about terrorism. Basically, a hole six feet across was bored down 600 feet. Rock drilling and crushing and moving equipment was then disassembled, lowered into the hole, reassembled by workers, and put to work. Rumor has it that most of that equipment is still down there.
They made a cavern that will hold somewhere in the neighborhood of half a million gallons of liquefied petroleum gas, which is then brought back up and delivered to homes. There are other storage facilities all over, but most of them are man-made tanks. During the summer, these storage facilities are filled up. During the winter, we take it back. Various amounts are predicted to be needed. If those predictions fall short? The price goes up.
Very quickly, here’s a cost comparison: Propane has come back down from $5 to just below $3. Divide 92,500 btus/gallon by 300 pennies (three bucks) and you get 308 btus/penny. New gas furnaces convert this into heat at 95 percent efficiency, so out of that 308 you get 293 btus for your penny.
Oil at four bucks a gallon: 140,000 btus/gallon divided by 400 pennies equals 350 btus. Oil furnaces maybe hit 80 percent, so you get 280 btus for a penny.
Natural gas is up around $9.30 an MCF (Roman numeral “M” means a thousand.). So, a thousand cubic feet, at 1,000 btus per CF, equals 1,000,000 btus divided by 930 (pennies), or 1,075 btus per penny. Take this times 95 percent efficiency, you get 1,021 btus for a penny.
We who live in the country wish we lived in town.
The Prairie Spy by Alan "Lindy" Linda