The Zero-Emissions Challenge, Part 4: Propane Appliances
Space heating uses up about half our propane, but what about the rest? It's used for cooking, hot water, and drying clothes— about 14 million BTUs, producing 1,950 pounds of CO2. We prefer propane over electricity for these applications because it is (1) cheaper, (2) more efficient, and (3) produces less CO2 per BTU than electric. But it's difficult to estimate how much we use for each appliance. And in these areas, reducing consumption becomes more challenging.
It would be easy to suggest that we dry our clothes outside on a clothesline, as my mom did when I was growing up. But it's not that simple: Utah has a problem with dust. The constant wind erodes topsoil and sends it across the landscape, looking for a place to settle. Homes need constant dusting, and barns accumulate it quickly. A line of wet clothes would attract it— and our white shirts would no longer be white.
The Conservation District encourages planting trees as windbreaks, and we've tried to do our part, with over fifty trees and shrubs that survived the harsh climate and hungry animals. But it hasn't made a noticable reduction in the wind as yet, so clothesline drying, except in an emergency, is still not an option.
We've worked to reduce our propane consumption by turning off the hot water heater when we go to bed. We could be more aggressive in this area, turning it on only when we need it. However, we find that the water loses its heat so slowly that when we turn the water heater back on after eight hours of sleep, the water is still hot enough that the burner doesn't kick on. This causes me to doubt that turning off the hot water heater for hours at a time is doing much to reduce our propane use.
There are some areas in which we could reduce our usage. Turning down the temperature on the hot water heater would help. The only place it really has to be 160 degrees is in the dishwasher, which will apply its own (electric) heat to ensure a sanitary wash. Also we could increase the insulation on the hot water pipes from the current 1/2 inch to an inch or more, saving on both propane and water use. And we could insulate and caulk the crawl space where the hot water pipes run, keeping it warmer and reducing heat loss in cold weather.
A gas range with a pilot light uses as much propane to keep the pilot lit as the average family consumes in cooking. For about $400, we could replace our range with one that has electronic ignition and cut our cooking usage in half. Similarly, there are water heaters that use electronic ignition and are more efficient than the one we now have. There's even a "tankless" on demand hot water heater that claims to be 30% more efficient than conventional models— it costs about $700, plus installation by a professional plumber, putting the installed cost in the neighborhood of $1,000.
Another energy-saving option would be install a solar hot water heating system in tandem with our propane hot water heater. Based on reports from those who have such systems, this would cut our propane use for heating water by about 3/4. However, one quote I received puts a system in the $7,000 range. I plan to experiment with a home-made version, but the very definition of experimentation means that there's no guarantee of success.
The bottom line is, though we don't know exactly how much each appliance uses, we could reduce our propane consumption somewhat by turning down the temperature on our hot water heater, insulating the pipes and crawl space, and replacing our range, all of which we can do ourselves. The new range would cost about $400, and the reduction in consumption from these changes would be minimal, maybe 10%, reducing our current 1,950 of annual CO2 emissions by only 195 pounds.
The next level of reduction would include having a new hot water heater and a solar hot water heater installed. Our wild guess is, this would cut our consumption by at least half, at a cost of about $8,300. That would bring our annual emissions from these appliances down to an estimated 975 pounds— a significant reduction, but nowhere near zero.Perhaps the best solution, at least in terms of global warming, would be to cook with wood. The woodstove we have in the barn is a wood-fired cookstove, set up and ready to go. But somehow, I don't see us making that transition anytime soon.
Comments