When we moved into our house, it had the original Maytag 18.5-cubic-foot refrigerator that was installed in 2000. It had one feature I had never lived with before: an icemaker.
It took me some time to realize that the weird sounds I occasionally heard coming from the fridge was it cranking out the cubes. We don’t use much ice, and being middle-aged actually learned in our youth how to fill ice cube trays (similar to being able to count, and tell time by the big hand and the little hand, and other lost arts), so eventually I turned that feature off.
Researchers at NIST recently reported that they tested four new refrigerators and the icemakers added 12 to 20 percent to the rated energy consumption. The not-so-cool discovery was that 75% of this energy comes from heating the molds to release the ice. Duh.
Oh, and the ratings you see on the big yellow sticker don’t include the energy used by the icemaker, apparently because someone decided it would be too hard to measure. Double duh.
The old refrigerator uses too much electricity
Anyway, being a complusive measurer, I plugged the Maytag into a kWh meter and measured its usage during March. This is a time of year where the house is perhaps slightly cooler than average. The annualized energy usage was 655 kWh. I knew I could do better, and maybe find a quieter refrigerator also.
I checked the Energy Star ratings and learned that the most efficient refrigerators were 16.5-cubic-foot models made by GE*, and that they didn’t make them anymore. This despite the fact that these units were well reviewed by owners.
Moving up to an 18.1-cubic-foot unit added 11 kWh/year, so after a few days of trying to find the last 16.5-cubic-foot model left, I capitulated to being an American and found that the 18.1-cubic-foot one I wanted was also discontinued in favor of a newer version that used more energy. Duh. (Are you sensing a trend here?)
I found the one I wanted, on sale as it happened, being discontinued and all, and bought it. It cost $517 shipped to Martha’s Vineyard (land of “No Free Shipping” Zip codes). It does not have an icemaker. It is rated at 335 kWh/year.
Comparing the cost of an efficient refrigerator to the cost of PV
I’ve been measuring its energy consumption and after about six weeks it looks like we’re headed for an annual energy usage of 260 kWh, unless it goes way up in the summer.
I gave the Maytag away. (I learned to my chagrin that all three of my work colleagues who immediately responded to my offer were intending to use this as a second, in-the-basement fridge.) The GE seems quieter than the Maytag, which we appreciate.
One test I use to evaluate whether something is a reasonable energy investment is to look at kWh saved and compare that with the cost of solar electric capacity to generate the equivalent amount of energy. In my opinion, this is reasonable, as long as the investments being compared have similar service life. I thought that a fridge mightn’t last as long as a solar electric system, so this wasn’t an optimal comparison. Anyway, here on Martha’s Vineyard we see that one watt of PV will make about 1.3 kWh/year, and has a marginal cost before subsidies of perhaps $4 – $5. If the GE fridge saves 400 kWh/year, that’s the output of about 300 W of PV costing $1,350 (assuming a cost of $4.50/watt for PV). So the fridge looks good.
* The most efficient refrigerators are actually still Sunfrost, but the margin is getting smaller, and the PVs cost less per kWh saved, and plus they are a pain to actually use because they are cube shaped so you need orangutan arms to reach half the stuff.
Marc Rosenbaum is director of engineering at South Mountain Company on the island of Martha’s Vineyard in Massachusetts. He writes a blog called Thriving on Low Carbon.