Documentation of Fuel Data & Energy Costs
Cutting Through the Noise
One of Zwell’s missions is to cut through all of the marketing-speak and misinformation around the clean energy space. We strive to provide you with accurate, fact-based estimates of the impact you’re likely to see in your home. In the interest of transparencey and shared knowledge, here is the underlying energy efficiency data used in all of our calculations on the site.
CO₂ Conversions by Fuel
| Energy Source | Convert To | Conversion | Source |
| Electricity (kWh) | CO₂ (lbs) | 0.85 | eia.gov |
| Natural gas (therm) | CO₂ (lbs) | 11.7 | eia.gov |
| Gasoline (gallon) | CO₂ (lbs) | 19.6 | eia.gov |
| Propane (btu) | CO₂ (lbs) | 0.000139 | eia.gov |
| Fuel Oil/Kerosene (btu) | CO₂ (lbs) | 0.0001613 | eia.gov |
Fuel Unit Conversions
| Unit | Fuel | kWh | ft3 | therm | quad | lbs CO2/btu |
| 1 btu | Electricity | 0.00029308 | N/A | N/A | 0.00000000000000100 | 0.000249 |
| 1 btu | Natural Gas | N/A | 0.00096 | 0.00001 | 0.00000000000000100 | 0.000117 |
| 1 btu | Propane | N/A | 0.00039 | 0.00001 | 0.00000000000000100 | 0.000139 |
| 1 btu | Fuel Oil/Kerosene | N/A | 0.000000965 | 0.00001 | 0.00000000000000100 | 0.000163 |
| 1 btu | Wood | N/A | N/A | N/A | 0.00000000000000100 | 0.0002706 |
| 1 btu | Gasoline | N/A | 0.00000111 | 0.00001 | 0.00000000000000100 | 0.000156 |
Relative CO₂ Impact of State-Level Grids
Source
| State | CO₂/btu of Energy Generated | State-Level Coefficient |
| Alabama | 47.60 | 0.90 |
| Alaska | 58.20 | 1.10 |
| Arizona | 51.40 | 0.97 |
| Arkansas | 56.70 | 1.07 |
| California | 50.80 | 0.96 |
| Colorado | 60.90 | 1.15 |
| Connecticut | 45.00 | 0.85 |
| Delaware | 58.00 | 1.09 |
| District of Columbia | 52.70 | 0.99 |
| Florida | 56.40 | 1.06 |
| Georgia | 51.50 | 0.97 |
| Hawaii | 67.10 | 1.26 |
| Idaho | 39.60 | 0.75 |
| Illinois | 48.40 | 0.91 |
| Indiana | 68.20 | 1.28 |
| Iowa | 48.90 | 0.92 |
| Kansas | 51.50 | 0.97 |
| Kentucky | 70.30 | 1.32 |
| Louisiana | 49.00 | 0.92 |
| Maine | 37.70 | 0.71 |
| Maryland | 53.10 | 1.00 |
| Massachusetts | 54.50 | 1.03 |
| Michigan | 54.60 | 1.03 |
| Minnesota | 51.40 | 0.97 |
| Mississippi | 53.90 | 1.02 |
| Missouri | 67.70 | 1.27 |
| Montana | 54.80 | 1.03 |
| Nebraska | 55.60 | 1.05 |
| Nevada | 53.50 | 1.01 |
| New Hampshire | 37.20 | 0.70 |
| New Jersey | 49.50 | 0.93 |
| New Mexico | 58.90 | 1.11 |
| New York | 45.80 | 0.86 |
| North Carolina | 49.10 | 0.92 |
| North Dakota | 66.30 | 1.25 |
| Ohio | 61.60 | 1.16 |
| Oklahoma | 52.40 | 0.99 |
| Oregon | 35.30 | 0.66 |
| Pennsylvania | 49.40 | 0.93 |
| Rhode Island | 56.10 | 1.06 |
| South Carolina | 41.20 | 0.78 |
| South Dakota | 39.70 | 0.75 |
| Tennessee | 48.80 | 0.92 |
| Texas | 49.00 | 0.92 |
| Utah | 67.80 | 1.28 |
| Vermont | 34.90 | 0.66 |
| Virginia | 50.40 | 0.95 |
| Washington | 34.80 | 0.66 |
| West Virginia | 78.00 | 1.47 |
| Wisconsin | 57.10 | 1.08 |
| Wyoming | 75.10 | 1.41 |
| National Average | 53.10 | 1.00 |
Average Energy Prices by State
Electricity Costs
Natural Gas Costs
| State | Electricity Cost ($/kWh) | Natural Gas Cost ($/therm) |
| Alabama | $0.10 | $2.23 |
| Alaska | $0.20 | $1.27 |
| Arizona | $0.11 | $2.38 |
| Arkansas | $0.08 | $2.25 |
| California | $0.17 | $1.53 |
| Colorado | $0.10 | $1.49 |
| Connecticut | $0.19 | $2.74 |
| Delaware | $0.11 | $2.57 |
| District of Columbia | $0.12 | $2.02 |
| Florida | $0.10 | $2.91 |
| Georgia | $0.10 | $3.14 |
| Hawaii | $0.29 | $4.81 |
| Idaho | $0.08 | $0.98 |
| Illinois | $0.10 | $2.24 |
| Indiana | $0.10 | $2.37 |
| Iowa | $0.09 | $2.15 |
| Kansas | $0.10 | $2.46 |
| Kentucky | $0.09 | $2.86 |
| Louisiana | $0.08 | $2.02 |
| Maine | $0.14 | $2.02 |
| Maryland | $0.11 | $2.27 |
| Massachusetts | $0.18 | $1.77 |
| Michigan | $0.12 | $1.51 |
| Minnesota | $0.10 | $1.44 |
| Mississippi | $0.09 | $2.16 |
| Missouri | $0.10 | $2.52 |
| Montana | $0.09 | $1.34 |
| Nebraska | $0.09 | $2.08 |
| Nevada | $0.09 | $1.53 |
| New Hampshire | $0.17 | $2.32 |
| New Jersey | $0.13 | $1.37 |
| New Mexico | $0.09 | $2.02 |
| New York | $0.14 | $2.23 |
| North Carolina | $0.09 | $1.86 |
| North Dakota | $0.09 | $2.02 |
| Ohio | $0.10 | $3.23 |
| Oklahoma | $0.08 | $2.80 |
| Oregon | $0.09 | $1.65 |
| Pennsylvania | $0.10 | $2.05 |
| Rhode Island | $0.18 | $2.13 |
| South Carolina | $0.10 | $2.11 |
| South Dakota | $0.10 | $1.92 |
| Tennessee | $0.10 | $2.02 |
| Texas | $0.09 | $2.40 |
| Utah | $0.08 | $1.11 |
| Vermont | $0.15 | $2.33 |
| Virginia | $0.10 | $2.51 |
| Washington | $0.08 | $1.60 |
| West Virginia | $0.08 | $2.05 |
| Wisconsin | $0.11 | $1.80 |
| Wyoming | $0.08 | $2.14 |
| National Average | $0.14 | $2.02 |
Energy Content by Fuel
Source
| Fuel | Energy Content |
| Gasoline | 116,090 btu/gallon |
| Low Sulfur Diesel | 128,488 btu/gallon |
| Biodiesel (B20) | 126,700 btu/gallon |
| Biodiesel (B100) | 119,550 btu/gallon |
| Compressed Natural Gas (CNG) | 923 btu/ft³ or 20,160 btu/lb |
| Liquefied Natural Gas | 21,240 btu/lb |
| Ethanol (E100) | 76,330 btu/gallon |
| Ethanol (E85)** | 88,258 btu/gallon |
| Electricity*** | 3,414 btu/kWh |
| Propane | 84,250 btu/gallon |
| Hydrogen | 288.88 btu/ft³ or 51,585 btu/lb |
U.S. Household Data
Source:
| Fuel Type | Number of Owned, Single-Family Homes | % to Total |
| Electric | 22,900,000 | 34.70% |
| Natural Gas | 32,300,000 | 48.94% |
| Propane | 2,800,000 | 4.24% |
| Fuel Oil/Kerosene | 3,200,000 | 4.85% |
| Other | 4,800,000 | 7.27% |
| Total | 66,000,000 | 100% |
