SOLAR TODAY - May 2009

inside ases ^|chair’s corner

Reduce, Re-Use, Recycle

Unplug the energy-hogging old refrigerator and give its components a second life.

By JOHN REYNOLDS,
FAIA

John Reynolds, FAIA, is chair of the American Solar Energy Society Board. Contact him at chair@ases.org.

Summer’s here, a fine time to discuss the household refrigerator. According to the Energy Star website ( energystar.gov), the refrigerator is the biggest energy hog in most kitchens: “Replacing a refrigerator bought in 1990 with a new Energy Star-qualified model would save enough energy to light the average household for nearly four months.”

What to do with that old refrigerator? I’m one of those who puts it to work elsewhere, to store spillover from the kitchen. In the hot garage or on the back porch, that old refrigerator draws more power than ever. American households harbor more than 47 million energy-hog fridges over 10 years old. To see what else can be done with them, I visited a Jaco refrigerator-recycling facility in Portland, Ore., part of a nationwide program.

Old refrigerators must be empty, in working order and, as proof, plugged in at time of pickup. The donor will soon get a check, typically about $30, for contributing to energy savings; there is no charge for pickup. The fridge is loaded on a truck and spray-painted with a huge X and a tracking number. Its power cord is cut, and its thermostat is smashed. Re-use is no longer an option.

At the recycling plant, a 1-inch core sample is bored to determine the type of insulation. In older models, manufactured between 1965 and 1993, CFC- 11 was used as a blowing agent for the polyurethane foam. CFC- 11 is both an extreme ozone depleter and a powerful greenhouse gas, so it requires special handling.

JAcO

At the Jaco refrigerator-recycling facility in Portland, Ore., the appliances are dismembered, separated and recycled.

The cooling circuit is punctured and the refrigerant, either CFC- 12 or HFC-134a, sucked into the proper vat. CFC- 12 (Freon) has similar characteristics to CFC- 11, while HFC-134a is another greenhouse gas. Some of the refrigerant can be resold; many older air conditioners, including those in autos, still need it. This re-use will be phased out as older models disappear. The rest is shipped to a qualified handler for disposal.

Compressor oil is drained and heated, to distill any refrigerant that leaked through worn seals. The purified oil can be used in other industrial equipment. Capacitors in older

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refrigerators contain polychlorinated biphenyls (PCBs), and must be shipped to hazardous waste facilities, as are thermostats and switches containing mercury.

The appliance is now dismembered; metals, plastics, glass and foam are separated. Aluminum is especially prized for recycling, because it saves so much of the electricity needed for smelting virgin aluminum. But quantities of steel are also recovered, and some copper tubing from refrigerators with icemakers. About 150 pounds of metal and perhaps 25 pounds of plastic are recycled from each refrigerator. Tempered glass shelves are crushed and recycled as concrete aggregate, as an addition to potting soil or even spread on dirt roads to inhibit dust.

Polyurethane foam insulation must be scraped off the metal shell, then bagged to capture outgassing. Each refrigerator will yield about 10 pounds ( 4. 5 kilograms) of foam and 1 pound of CFC- 11; these yield 15 kilowatt-hours of electricity at energy incinerators that provide complete, safe destruction.

In all, about 95 percent of each refrigerator can be recycled, instead of outgassing in a landfill.

Chastened, I came home to my newer fridge in the kitchen and my older, smaller one downstairs in my office. The smaller fridge had been so useful for storing that watermelon awaiting dinner guests, bottles of beer, white wine, champagne and soft drinks. I opened it perhaps three times a month. I carried the contents upstairs and found space in the kitchen fridge, then turned the controls off downstairs. I will clean it periodically to fight off mold and power it up a day or two at a time for those special occasions with many guests. Otherwise, it will take up space but won’t use electricity.

Is there such a thing as a solar refrigerator? There are highly efficient DC refrigerators that can run off a photovoltaic (PV) panel, or from a battery, without the inverter and its power loss. But for most homes with PV, inverters yield the AC power that is required by the vast majority of common appliances, lights and motors. The refrigerator, however, need no longer be the biggest electricity hog.

In fact, refrigerators can be useful participants in the new smart grids featured in this issue. As with domestic water heaters, refrigerators have storage capacity that allows them to take electricity when it is most abundant and refuse it when most scarce. The smart fridge would cooperate with intermittent electricity sources such as wind and solar.