Documenting my attempt to cut my energy usage in half.

Monday, August 13, 2012

Refrigerator Analysis

 

Our current refrigerator is a GE Profile 24.7 ft^3, model number TBX25PAB that was manufactured in March of 2001.  As part of our Half Project, I was interested is seeing how our refrigerator (which is not Energy Star rated) compared to a newer model refrigerator and to see if it made sense to upgrade.

The power consumption of the current refrigerator was measured with a Kill-A-Watt meter over the course of several weeks at 2.4 kWh/day, or 876 kWh/year.  For our area, Dominion Power charges us approximately $0.11/kWh, so our cost to run the refrigerator is $96/year which is about 3% of our yearly energy consumption.

The Energy Star website has a refrigerator/freezer calculator that you can use to calculate the operating costs of your current appliance.  I used this to compare the actual usage data that I collected with the estimated usage from Energy Star.  The chart below shows that the estimated usage is slightly higher than my actual usage, but it is within 10% which is acceptable for an estimate.

Model Data kWh $/kWh

Per year cost

GE TBX25

Actual 876 0.11 $96

GE TBX25

Estimated 961 0.11 $106

 

GE makes a newer version of the Profile series which is a direct replacement for what I currently have.  It is a little pricey at $1800 but let’s look at its performance.  First of all I’ll ignore the fact that the Sears website has conflicting data with the Energy Star label over yearly kWh usage and I’ll just use the data from the Energy Star label. 

Model Data kWh $/kWh

Per year cost

GE PTS25

Estimated 560 0.11 $61

Using the Energy Star estimates for both the old and new refrigerator I can expect to get the following savings.

Energy Saving/year 401 kWh
$’s Saved/year $44.11
Initial Cost $1800
1st year Return < 2.5%
CO2 Reduction 441 lbs

With a payback period of ~40 years, upgrading to the newer model GE Profile just doesn’t make sense right now.  It’s time to research other models of refrigerators.

1 comment:

  1. Hi Dave. I just discovered your blog today and look forward to reading each and every entry ... our family has been attempting the very same goal of cutting our energy by half and have been working on it since 2005. We have had great results ... the key to such a project is just getting started and working away at it bit by bit.

    Regarding this entry on refrigeration ... We replaced an 8 year old 18 cu ft energy star refrigerator with two chest freezers, one large and one small. The large one is our "refrigerator" ... it is hooked up to a thermostat override that beer kegorator folks use (purchased online from Johnson controls). This makes for a very well insulated and roomy refrigerator that doesn't allow all the cold air to fall out each time you open the door. It uses about .45 kw a day. The small chest freezer is our freezer. The old energy star refrigerator cost about $92 a year to operate, whereas these two freezers cost a combined $36. Best of all, good energy star chest freezers are very affordable ... maybe $350 each.

    The two potential "problems" with this scenario are having room in your kitchen for two freezers and the need to wipe out collected condensation from the chest refrigerator every other week. Neither of these were show stoppers for us and we have been very happy with the results.

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