WattCost

Data through April 2026

Running cost · Water Heaters (Electric) · ENERGY STAR certified

Navien NWP500S050AUMB

For a standard household draw pattern, the Navien NWP500S050AUMB uses a certified 840 kWh per year: roughly $158 annually at the national average rate. That puts it in the most efficient tenth of every certified electric water heater — 22% less electricity than the median, ranked 35 of 566. Where you live moves the bill from $104 a year in North Dakota to $392 in Hawaii.

Estimated annual running cost · U.S. average rate 18.8¢/kWh

$158/yr

$121 · cheapest certified water heaters (electric)$328 · priciest
Per month
$13.18
Per day
43¢
Certified use
840 kWh/yr
Type
Hybrid/Electric Heat Pump
Heat pump type
240 Volt Integrated HPWH
Storage volume
44 gal
First-hour rating
65 gal
UEF
3.85
643 kWh1,741 kWh
Where the Navien NWP500S050AUMB (▮) sits among all 566 certified water heaters (electric), by annual kWh

What it costs in every state

Navien NWP500S050AUMB: 840 kWh/yr × each state's average residential rate (EIA)
StateRate ¢/kWhThis model $/yrRelative cost
Alabama17.4¢$146
Alaska27.4¢$230
Arizona15.5¢$130
Arkansas14.2¢$119
California35.3¢$296
Colorado16.5¢$139
Connecticut32.2¢$271
Delaware18.8¢$158
District of Columbia25.4¢$213
Florida15.4¢$129
Georgia15.4¢$129
Hawaiipriciest46.6¢$392
Idaho12.7¢$107
Illinois20.5¢$172
Indiana17.9¢$150
Iowa13.9¢$116
Kansas15.8¢$133
Kentucky15.0¢$126
Louisiana14.4¢$121
Maine28.4¢$239
Maryland22.1¢$185
Massachusetts29.4¢$247
Michigan21.4¢$180
Minnesota16.4¢$138
Mississippi16.8¢$141
Missouri14.0¢$118
Montana13.9¢$117
Nebraska13.3¢$112
Nevada14.3¢$120
New Hampshire27.2¢$229
New Jersey23.5¢$198
New Mexico15.2¢$127
New York29.4¢$247
North Carolina16.3¢$137
North Dakotacheapest12.3¢$104
Ohio19.5¢$164
Oklahoma13.3¢$112
Oregon15.8¢$133
Pennsylvania21.5¢$180
Rhode Island28.3¢$238
South Carolina17.1¢$143
South Dakota14.5¢$122
Tennessee14.9¢$125
Texas17.0¢$143
Utah13.3¢$112
Vermont24.6¢$206
Virginia17.4¢$146
Washington14.4¢$121
West Virginia16.1¢$135
Wisconsin19.2¢$161
Wyoming14.7¢$123

Certified models closest in efficiency

electric water heaters within reach of 840 kWh/yr
ModelkWh/yr$/yr (US avg)
Arctic Arctic-HP-Hot Water-KA06-50837$158
PHNIX KA06-50837$158
Rinnai REHP50844$159
Rinnai REHP50BM844$159
Rinnai REHP50C844$159
Bradford White RE2HP50**-1NCTT835$157

Run your own numbers

Your rate, your numbers

Per day
43¢
Per month
$13.18
Per year
$158

840 kWh/yr × 18.8¢/kWh = $158/yr

Prefilled with this model's certified 840 kWh/yr — adjust if your usage differs from the DOE test basis. The certified annual kWh comes from the DOE Uniform Energy Factor test, which simulates a typical household's daily hot-water draw pattern. Only electric models (including heat-pump units) are listed — gas models burn gas, not kWh.

Questions, answered with the data

How much electricity does the Navien NWP500S050AUMB use?
ENERGY STAR certifies the Navien NWP500S050AUMB at 840 kWh per year. The certified annual kWh comes from the DOE Uniform Energy Factor test, which simulates a typical household's daily hot-water draw pattern. Only electric models (including heat-pump units) are listed — gas models burn gas, not kWh.
How much does the Navien NWP500S050AUMB cost to run per month?
About $13.18 a month at the U.S. average residential rate (18.8¢/kWh) — 43¢ a day, or $158 a year. Your state's rate moves this up or down; see the table above.
Is the Navien NWP500S050AUMB energy efficient?
It uses 22% less electricity than the median certified electric water heater, placing it in the top 10% of certified models.
What does the Navien NWP500S050AUMB cost to run in the cheapest vs. priciest state?
At current residential rates it costs about $104 a year in North Dakota (12.3¢/kWh) and $392 in Hawaii (46.6¢/kWh).

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