Transition planning is complex because it requires meeting increasing electricity demand with lower carbon intensity electricity sources while maintaining reliability and affordability. 

T&D capacity and curtailment primarily affect volumes, as opposed to net unit impact. In the example of a renewable energy source displacing a fossil fuel energy source, GHG impact should focus on where the solution and incumbent are different, including in downstream inefficiencies.

Until the grid reaches net zero, there's room for GHG impact if, for example, the intervention displaces fossil generation or has systemic effects (like accelerating coal retirement). Broader impacts may warrant adjustment factors in impact quantification. 

Electricity generation sources, like wind, solar, hydropower, geothermal, and fossil fuels (like coal and natural gas), and nuclear energy, differ in both how emissions are generated and how reliably they supply power. Read more for an overview of how these major generation sources compare, based on the geography of the US.

There are broadly 3 steps to creating and using electricity: generation, transmission, and distribution. This FAQ provides an overview of electricity generation, transmission, and distribution.