Model
Element ERT21CS**
Rank #611 means 610 of the 1,000 refrigerator models we track cost less to run each year; the 94th efficiency percentile means it uses less energy for its size than 94% of those models.
What does the Element ERT21CS** cost to run per year?
Among the 1,000 refrigerator models we track, the Element ERT21CS**'s $72/yr running cost ranks it #611, in the above-average-cost group. It uses 10% less energy than the U.S. federal standard model in its class, which would cost about $81/yr to run, a saving of roughly $9 a year. Its size-adjusted efficiency percentile of 94 means the low running cost is not just a function of size; it is genuinely efficient for its class. This class has no published efficiency-factor figure beyond annual kWh itself, so at 20.5 cu ft (the class spans 1.2 to 31.7), size is the clearest lever we can point to for this model's running cost.
Immediately around it on the leaderboard, the Moffat MBE11DSVSS at $72/yr runs a little cheaper and the Insignia NS-RTM20**3 at $72/yr runs a little more, a sense of how tightly models are packed at this point in the ranking. A refrigerator typically stays in service for somewhere around 12 years; over that span, the Element ERT21CS**'s $72/yr adds up to roughly $864 in electricity alone, before purchase price or repairs.
Also sold as: Insignia NS-RTM20**3, Midea MRT21D3***.
By the numbers
The Element ERT21CS** normalized against its whole class, so each figure means something.
What it costs you over time
Running cost is an every-year number, so it compounds. At $72/yr, here is what the Element ERT21CS** adds up to before purchase price, water, or repairs enter the math.
Left running for a decade at today's US average rate, the Element ERT21CS** costs about $720. That is roughly $90 less than a standard model in its class, which would run closer to $810 over the same ten years.
How the Element ERT21CS** compares
The refrigerator class we track runs from $8 to $149 a year. At $72/yr, it runs about $8 a year above the class median of $64, and it is about $64 a year more than the cheapest refrigerator to run at $8. Against the US federal standard model for its class at about $81/yr, the Element ERT21CS** uses 10% less energy.
What drives its running cost
At 20.5 cu ft, the Element ERT21CS** is a large refrigerator for its class, which spans 1.2 to 31.7 cu ft with a median of 12.6 cu ft, size is usually the single biggest lever behind a running-cost figure, and at this end of the range there is more capacity to service, which tends to push the number up.
- Interior volume. More cubic feet of cold air to maintain generally means a bigger compressor and a higher running-cost figure, even among efficient models.
- Counter depth vs standard depth. Standard-depth models generally offer more interior volume per unit of width than counter-depth models, a tradeoff between built-in looks and cubic feet.
- Compressor technology. How a compressor cycles, full on/off versus a variable-speed inverter design, is one of the biggest hidden differences behind two fridges with similar cubic feet but different running costs.
- Placement and ventilation. Ventilation clearance around the back and top matters more than most owners expect; a fridge starved of airflow runs its compressor longer to hold the same temperature.
Common questions
Is the Element ERT21CS** cheap to run?
Its $72/yr running cost, rank #611 of 1,000, is above what most refrigerator models we track cost to run, so this is not one of the cheaper picks on electricity alone.
How much does the Element ERT21CS** cost per month?
About $6.03 a month, which is the $72 annual estimate spread across twelve months at the US average rate of $0.1856/kWh. Your own bill scales with your local electricity rate and how heavily you use it.
How is this running-cost figure calculated?
The formula is annual kWh times price per kWh: 390 kWh from ENERGY STAR times the US average of $0.1856/kWh comes to about $72 a year. It covers electricity only, not the purchase price, water, or installation.
How efficient is the Element ERT21CS** for its size?
94th percentile once size is factored in. That means its size-adjusted efficiency is a real factor in the running-cost figure above; its capacity plays a large role too.
Cheaper to run in the same class
| Rank | Model | Cost/yr |
|---|---|---|
| 610 | Moffat MBE11DSVSS10.9 cu ft | $72 |
| 609 | Black Decker BR2010JS20.1 cu ft | $72 |
| 608 | Smeg CB300U8.4 cu ft | $72 |
| 607 | Marvel MLRF*24-SS*1A4.9 cu ft | $72 |
| 606 | Frigidaire FFHT2033V*20.4 cu ft | $72 |
Source
ES_1145034_ERT21CS**_120720231040620_9729309View certified refrigerator listingsENERGY STAR data as of July 2026Element and ERT21CS** are used here for identification only and are not endorsements. Figures are computed by WattWise Labs from public ENERGY STAR data, not measured in our own lab.