Why Some ENERGY STAR Refrigerators Cost 19x More to Run

The most efficient ENERGY STAR certified refrigerator on the market uses 42 kWh a year; the least efficient certified model uses 805 kWh — a 19-fold gap between two products that carry the exact same certification. ENERGY STAR is a minimum efficiency bar, not a ranking, and refrigerators show that gap more starkly than almost any other category.

What ENERGY STAR certification actually guarantees

A refrigerator that's ENERGY STAR certified has passed a DOE test procedure measuring continuous 24/7 operation at standardized temperatures — refrigerators are an always-on duty class, so unlike a dryer or an air conditioner, there's no "hours of use" assumption to adjust. The certified annual kWh figure is close to what you'll actually get, regardless of your habits, because the compressor cycles on its own schedule rather than yours.

What certification doesn't guarantee is that two certified models use anywhere close to the same amount of energy. Across the 4,229 certified refrigerator models in WattCost's dataset, the median is 345 kWh a year — but the range runs from 42 kWh to 805 kWh.

The compact vs. side-by-side story

The most efficient certified models are small — compact coolers like the Fisher & Paykel RS2435V2 at 42 kWh a year, built for a single small space rather than a household's main kitchen fridge. The least efficient certified models are full-size side-by-side refrigerators, including several KitchenAid and Jenn-Air models at 805 kWh a year.

Size explains most, but not all, of the gap. Within the same subgroup — comparing side-by-side to side-by-side, or compact to compact — certified models still spread by a factor of 2–3x depending on compressor design, insulation, and defrost method. See the full ranked list of the most efficient full-size refrigerators and the priciest refrigerators to run for exact models.

Your state matters almost as much as the model

At the US average rate, the median certified refrigerator costs $64.96 a year to run. That figure swings hard by state: in North Dakota, the cheapest electricity in the country (12.35¢/kWh), the same median refrigerator costs about $42.61 a year. In Hawaii, the most expensive (46.62¢/kWh), it costs about $160.84 — a 3.8x difference for an identical machine. See the cheapest states to run a refrigerator for the complete ranking.

Combine both effects — an inefficient side-by-side in a high-rate state versus an efficient compact in a low-rate one — and the real-world spread between two refrigerators easily exceeds 50x.

What actually moves the number

• Size and configuration. Compact and single-door models use dramatically less energy than full-size side-by-side units, independent of brand.
• Age and compressor type. Newer compressor and insulation technology has pushed certified efficiency down substantially over the past decade.
• Your electricity rate. A 3–4x rate difference between states moves the dollar cost by the same multiple, with zero change to the appliance itself.

FAQ

Does ENERGY STAR certification mean a refrigerator is the most efficient option? No — it means the model meets a minimum efficiency bar for its category. Certified models still range from 42 to 805 kWh a year; check the specific model's page rather than assuming the certification alone tells you the cost.

Why do side-by-side refrigerators cost more to run than top-freezer models? Side-by-side configurations have more door seals, more surface area for heat exchange, and typically more usable volume to keep cold, all of which increase energy use.

Is a refrigerator's running cost the same everywhere in the US? No — the same certified model can cost roughly 3–4x more in a high-electricity-rate state like Hawaii than in a low-rate state like North Dakota.

How is the certified annual kWh figure measured? Through a DOE test procedure simulating continuous 24/7 operation at standardized temperatures — refrigerators don't get an "hours of use" adjustment because they never turn off.

For the full ranked list of both efficient and inefficient certified models, see the refrigerators category page, or read where refrigerators rank against every other appliance in the home.