Fuel Types

Fuel Mix

Your utility company gets power from many different fuel sources such as Solar, Wind, Coal, Oil, Nuclear, and Natural Gas. Depending on your region, your utility may use more or less of a certain type (or not have that type available).

fuel types
Fuel Type Carbon Intensity

The Carbon Intensity number associated with each fuel type is an estimate of its environmental impact.

This number ranges from close to 0 to ~2 (in lbs/kWh). The higher the number, the higher the impact, the dirtier the fuel type.

what is carbon intensity
High vs Low Carbon

Below are the average carbon intensities for common fuel types. The number may vary in your region.

For example, Coal, being mostly carbon, emits a lot of CO2 when burnt: it has a high Carbon Intensity.

fuel type carbon intensity
Renewables: Are they all clean?

Some fuel types are categorized as ‘renewable’. Renewable energy is collected from resources which are naturally replenished (e.g. Solar, Wind, Hydro, Wood). This type of energy source stands in contrast to fossil fuels (e.g. Oil, Coal, Natural Gas), which are being used far more quickly than they are being replenished.

Renewables like Solar, Wind and Hydro have very low Carbon Intensities close to zero. But not all renewables are low impact: Wood and Refuse (trash) produce a lot of carbon when burnt.

renewables carbon intensity
Nuclear: The pros and cons
nuclear pros and cons

Pros: Nuclear energy is carbon-free, so from a carbon impact standpoint, it’s low! Nuclear energy is generated without carbon emissions because the reactors use uranium, not fossil fuels. Once things are set up, nuclear is cheap to run and can run without any interruptions or maintenance for over a year, making it a reliable source of energy.

Cons: It’s expensive to build. If something goes wrong (e.g. nuclear meltdown) it can be harmful to the environment. It produces waste that is difficult to dispose of and there is carbon impact via the processes for mining and refining the uranium.

That said, new innovations in nuclear technology are making it safer and more affordable as an energy source. There is also progress being made to address the waste problem by reusing the depleted uranium (what’s left over) to power the reactors.


What is Carbon Intensity? →