defining carbon neutral and related renewable energy terms

The Carbon Balancing Act: Defining Carbon Neutral Terms

Commitments to more renewable forms of electricity generation are made for greater sustainability, to reduce costs, and to reduce carbon dioxide (CO2) and other greenhouse gas emissions, key contributors to global warming. (Annenberg Learner)

Understanding Renewable Industry Terms

It’s important to understand the differences between energy industry descriptors like carbon neutral, zero net carbon, carbon free, carbon negative, and 100% renewable. These terms can be overwhelming to everyone because they sound alike. Voters, ratepayers, regulators, elected officials, and power companies must use the same set of definitions when speaking the language of renewables so that all parties are heard clearly and effectively.

Carbon Neutral

New Oxford American Dictionary’s word of the year in 2006. However, most of us haven’t used it until the last few years. It describes power generation that releases net zero carbon dioxide (CO2) emissions into the atmosphere. (Fast Company, 2018)

Power generation considered carbon neutral would include wind, solar, geothermal, micro-hydro, synthetic fuels and wave energy. (, May 2013) Interestingly, biofuels are not included in a zero carbon category ( because producing biofuels contributes more carbon dioxide to the atmosphere than it displaces in energy generation.

Take wind generation as an example. The total carbon footprint of wind generation can be calculated by comparing the following:

  1. How much CO2 is added to the atmosphere to manufacture the wind turbines and transport them many miles to wind farm locations.
  2. The amount of CO2 emissions that would occur to produce the same amount of electricity the wind turbines produce, only using fossil fuel generation.

If that comparison shows no increase in CO2 added to the atmosphere, then the power generation method is considered to be carbon neutral.

Zero Net Carbon or Net Zero Carbon

These have the same meaning as Carbon Neutral.

Carbon Free or Zero-Emission

This refers to one part of the carbon footprint calculation: describing power generation which does not emit greenhouse gas into the atmosphere (such as nuclear or renewables). However, it does not address CO2 emissions from fossil fuels used to source, produce and distribute generation.

Carbon Negative and Climate Positive

These terms are interchangeable even though they seem contradictory. Both describe activities that remove additional CO2 from the atmosphere (as opposed to simply “netting-out” carbon emissions).

100% Renewable

This is a claim communities can make if they have power purchasing agreements for 100% renewable generation.

One key thing to remember is that 100% Renewable doesn’t mean the electricity generated by a wind farm or solar farm is going directly to the homes and businesses of customers within a community.

Instead, the claim means that communities with 100% renewable contracts are paying for renewable generation on the grid, and they may be doing so alongside other communities on that same grid who are paying for electricity generated by fossil fuels and/or nuclear. It doesn’t matter who consumes the electricity from the renewables or thermal generation, because an electron is an electron.

What matters most is that more renewable energy is generated because of these agreements. Commitments to 100% renewable power will reduce the reliance on fossil fuel generation, transition communities to a more sustainable power supply and in many cases will result in lower power prices. (Forbes 2018)

Have other power industry terms you’d like to know more about? Check out our Path to 100% Renewables Energy Glossary.