How Our Carbon Calculator Works
From what we've seen, other carbon offsetting sites produce carbon emissions figures that are vastly over-estimated. We use the following information to base our calculations on, and constantly check the latest emissions reports for all energy providers.
Carbon Emissions Generated By Energy Consumption
We use the following costs to calculate your energy consumption if you only specify cost: 10p/kWh electricy, 6p/kWh gas. Figures were obtained from here.
Average Household Energy Consumption Per Bedroom (more details)
| Number of Bedrooms |
Average kWh Consumption Per Year (Gas) |
Average kWh Consumption Per Year (Electricity) |
| 1 |
10,000 |
2,500 |
| 2 |
15,000 |
4,000 |
| 3 |
25,000 |
5,500 |
| 4 |
29,000 |
6,000 |
| Consumption per additional bedroom |
2,500 |
250 |
Carbon Emissions per kWh per Energy Supplier (more details)
| Supplier |
Carbon Emissions (kg) |
| Average (electricity) |
0.461 |
| Brittish Gas (electricity) |
0.354 |
| EDF Energy (electricity) |
0.527 |
| Good Energy (electricity) |
0 |
| npower/RWE (electricity) |
0.507 |
| Powergen (electricity) |
0.619 |
| Scottish & Southern Energy (electricity) |
0.520 |
| Scottish Power (electricity) |
0.580 |
| Average (gas) |
0.19 |
Carbon Emissions Generated By Consumer Goods
We worked out a rough figure for consumer wast/emissions from these sources: here or here.
A green consumer will produce around 1 tonne, and an average consumer around 2 tonnes per year. You can calculate a more accurate figure using the resources on those sites, but these figures are accurate enough for most uses.
Carbon Emissions Generated By Transport
DEFRA produced a list of emissions figures which provides information on rail transport here. From that we have an average figure of 0.064374 tonnes of carbon dioxide emissions per mile for electric trains based on average National Grid prices.
For flight distances, we work out longest distances for three flight types from here.
| Flight Type |
Max Distance (miles) |
Carbon Emissions (kg max) |
Carbon Emissions (kg/mile) |
| Short |
500 |
120 |
0.241402 |
| Medium |
3,000 |
750 |
0.225709 |
| Long |
13,000 |
2,300 |
0.177028 |
For emissions from automotive transport we use carbon emissions data in terms of g/km from here. To enter more accurate information into our carbon calculator, look up your car information there.
|