Running a water heater
in Delaware
Meter reading
per year
1,015 kWh certified × 19.38¢ per kWh ÷ 100 — median of 680 listed models
Default: Delaware residential average, 19.38¢ per kWh, EIA JUL 2026. Overwrite it with the rate printed on your own bill.
SOURCE·ENERGY STAR certified product data·tariff Delaware residential average 19.38¢ — EIA Electric Power Monthly, retrieved 2026-07-28·REVIEWED JUL 2026
$196.71 a year A typical ENERGY STAR certified water heater uses 1,015 kWh a year. At Delaware's average residential price of 19.38¢ per kWh, that is $196.71 a year, or $16.39 a month.
The tariff scales the whole rail; the model you buy is what moves the gate along it. The most efficient certified water heater on this tariff draws $124.61 a year, the least efficient $337.41 — a standing difference of $212.79 a year for an appliance doing the same job.
How this is worked out
- Take the certified annual consumption for the appliance class off the EPA's ENERGY STAR register — the median of every listed model, not a wattage anyone assumed.
- Take the residential tariff off the EIA's Electric Power Monthly, table 5.6.A. Here that is Delaware's residential average, 19.38¢ per kWh.
- Multiply, then divide by 100 to come out of cents. Nothing is rounded before this line.
- Derive the rest of the schedule from that one figure: ÷ 12 monthly, ÷ 365 daily, × 10 for a ten-year life.
- Overwrite the tariff terminal with the rate printed on your own bill and the register re-reads. The certified consumption does not move — that is the half of the sum nobody gets to opinion their way out of.
annual cost ($) = certified kWh per year × tariff ¢ per kWh ÷ 100
Every certified water heater, cheapest to run first
The register above reads the median. This is the whole list it was taken from, priced at Delaware's tariff. Running cost only — purchase price, capacity and repair record are not in this column, and a cheap-to-run model is not automatically the right buy.
| # | Model | kWh/yr | Cost/yr | vs typical |
|---|---|---|---|---|
| 1 | Friedrich PROH40 T2 FD400-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 2 | Rheem CPROPH40 T2 RH400-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 3 | Rheem CXE40T10H22U1 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 4 | Rheem ECEPH40 T2 RH400-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 5 | Rheem PROPH40 T2 RH375-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 6 | Rheem PROPH40 T2 RH400-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 7 | Rheem XE40T10H22U0 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 8 | Rheem XE40T10H22U1 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 9 | Richmond 10CE40-HP5U15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 10 | Richmond 10E40-HP515 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 11 | Richmond 10E40-HP5U15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 12 | Ruud PROUH40 T2 CD400-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 13 | Ruud PROUH40 T2 RU375-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 14 | Ruud PROUH40 T2 RU400-15 · Hybrid/Electric Heat Pump | 643 | $124.61 | saves $72.09 |
| 15 | Eco-Logical OMNI-50HP1-1A · Hybrid/Electric Heat Pump | 681 | $131.98 | saves $64.73 |
| 16 | GE Profile PF40S10FPY01 · Hybrid/Electric Heat Pump | 724 | $140.31 | saves $56.40 |
| 17 | GE Profile PJ40S10FPY01 · Hybrid/Electric Heat Pump | 724 | $140.31 | saves $56.40 |
| 18 | Eco-Logical OMNI-50HP2-1A · Hybrid/Electric Heat Pump | 769 | $149.03 | saves $47.67 |
| 19 | GE Profile PH40S10BPY01 · Hybrid/Electric Heat Pump | 773 | $149.81 | saves $46.90 |
| 20 | GE Profile PK50S10FNY01 · Hybrid/Electric Heat Pump | 773 | $149.81 | saves $46.90 |
SOURCE·ENERGY STAR certified product data·680 certified water heaters on the register, listed by certified consumption·REVIEWED JUL 2026
What the certification spread is worth on this tariff
| Certified models in this category | 680 |
|---|---|
| Lowest certified energy use | 643 kWh/yr — $124.61/yr |
| Median certified energy use | 1,015 kWh/yr — $196.71/yr |
| Highest certified energy use | 1,741 kWh/yr — $337.41/yr |
| Difference, best to worst | $212.79 a year |
| …over a 10-year life | $2127.92 |
SOURCE·ENERGY STAR certified product data·priced at Delaware's residential average, 19.38¢ per kWh·REVIEWED JUL 2026
The same water heater on 51 tariffs
| State | Price per kWh | Cost per year | Per month |
|---|---|---|---|
| Hawaii | 52.00¢ | $527.80 | $43.98 |
| California | 33.25¢ | $337.49 | $28.12 |
| New York | 29.93¢ | $303.79 | $25.32 |
| Rhode Island | 29.46¢ | $299.02 | $24.92 |
| Massachusetts | 28.82¢ | $292.52 | $24.38 |
| Maine | 28.63¢ | $290.59 | $24.22 |
| Alaska | 28.23¢ | $286.53 | $23.88 |
| Connecticut | 27.37¢ | $277.81 | $23.15 |
| New Hampshire | 27.33¢ | $277.40 | $23.12 |
| District of Columbia | 25.40¢ | $257.81 | $21.48 |
| Vermont | 24.89¢ | $252.63 | $21.05 |
| Illinois | 23.85¢ | $242.08 | $20.17 |
| New Jersey | 23.27¢ | $236.19 | $19.68 |
| Michigan | 22.01¢ | $223.40 | $18.62 |
| Maryland | 21.77¢ | $220.97 | $18.41 |
| Pennsylvania | 21.55¢ | $218.73 | $18.23 |
| Wisconsin | 19.74¢ | $200.36 | $16.70 |
| Ohio | 19.52¢ | $198.13 | $16.51 |
| Delaware | 19.38¢ | $196.71 | $16.39 |
| Indiana | 18.15¢ | $184.22 | $15.35 |
| Virginia | 17.61¢ | $178.74 | $14.90 |
| Minnesota | 16.95¢ | $172.04 | $14.34 |
| West Virginia | 16.80¢ | $170.52 | $14.21 |
| Alabama | 16.77¢ | $170.22 | $14.18 |
| Texas | 16.44¢ | $166.87 | $13.91 |
| Oregon | 16.27¢ | $165.14 | $13.76 |
| South Carolina | 16.18¢ | $164.23 | $13.69 |
| Colorado | 16.16¢ | $164.02 | $13.67 |
| Mississippi | 16.16¢ | $164.02 | $13.67 |
| Georgia | 15.84¢ | $160.78 | $13.40 |
| South Dakota | 15.73¢ | $159.66 | $13.30 |
| Arizona | 15.23¢ | $154.58 | $12.88 |
| Florida | 15.17¢ | $153.98 | $12.83 |
| Kansas | 15.13¢ | $153.57 | $12.80 |
| North Carolina | 15.09¢ | $153.16 | $12.76 |
| Kentucky | 14.98¢ | $152.05 | $12.67 |
| Washington | 14.95¢ | $151.74 | $12.65 |
| Wyoming | 14.80¢ | $150.22 | $12.52 |
| Montana | 14.67¢ | $148.90 | $12.41 |
| Tennessee | 14.47¢ | $146.87 | $12.24 |
| Arkansas | 14.36¢ | $145.75 | $12.15 |
| Louisiana | 14.15¢ | $143.62 | $11.97 |
| Iowa | 14.14¢ | $143.52 | $11.96 |
| New Mexico | 14.12¢ | $143.32 | $11.94 |
| Missouri | 13.68¢ | $138.85 | $11.57 |
| North Dakota | 13.61¢ | $138.14 | $11.51 |
| Nevada | 13.60¢ | $138.04 | $11.50 |
| Nebraska | 13.59¢ | $137.94 | $11.49 |
| Oklahoma | 13.38¢ | $135.81 | $11.32 |
| Utah | 12.96¢ | $131.54 | $10.96 |
| Idaho | 12.35¢ | $125.35 | $10.45 |
One certified water heater at the median consumption of 1,015 kWh a year, wired to 51 different tariffs. Same appliance, same duty cycle, same certification — only the tariff changes.
SOURCE·US EIA Electric Power Monthly, table 5.6.A·retrieved 2026-07-28·REVIEWED JUL 2026
Schedule notes
How much does it cost to run a water heater in Delaware?
About $196.71 a year — $16.39 a month — for a typical ENERGY STAR certified water heater using 1,015 kWh annually, at Delaware's average residential rate of 19.38¢ per kWh.
How much electricity does a water heater use?
Certified models range from 643 to 1,741 kWh a year, with a median of 1,015 kWh. That spread means the model you choose changes the running cost by $212.79 a year in Delaware.
Is that more or less than the rest of the country?
Delaware has the 19th highest residential electricity price of the 51 states and DC, at 19.38¢ against a national average of 19.41¢. The same water heater costs $197.01 a year at the national average — $0.30 more than you pay.
Will my bill actually go up by this much?
Only roughly. This is the certified test figure at your state's average price. Your own tariff, how heavily you use the appliance, and its age all move the real number. Older non-certified appliances often use considerably more.
Other circuits on the Delaware tariff
Same tariff, same method, one certified median each.
Consumption: US EPA ENERGY STAR certified product data. Tariff: US EIA Electric Power Monthly, retrieved 2026-07-28. Estimates for comparison only. Your actual bill depends on your tariff, how often you run the appliance, and local conditions.
