Sankey Diagram
This visual feature of a Sankey flow line indicates its scale or quantity.
What is thickness (or width)?
This specific fossil fuel is consumed in the single highest quantity nationwide.
What is petroleum (or oil)?
This sector is uniquely vulnerable because it relies almost entirely on petroleum.
What is the Transportation sector?
Compared to 100 years ago, America's reliance on this solid fossil fuel has plummeted.
What is coal?
If an efficiency trend line rises over time, the system is producing less of this.
What is rejected energy (or waste heat)?
This massive destination label represents energy lost to the environment as heat.
What is Rejected Energy?
This clean-burning fossil fuel is heavily used across electricity, industry, and home heating.
What is natural gas?
Between the two building sectors, this one consumes more total energy nationwide.
What is the Residential sector?
This specific sector has shown the most consistent growth and grid addition over 20 years.
What is the renewable energy sector?
The vast majority of petroleum put into a standard car engine is wasted as this byproduct.
What is heat?
This broad resource type (renewable or nonrenewable) dominates the national input flow.
What is nonrenewable?
Once the king of electricity generation, this resource's usage has faced a massive decline.
What is coal?
Manufacturing and refining facilities fall under this heavily-consuming sector.
What is the Industrial sector?
Over the last century, our power infrastructure shifted from local systems to this.
What is the centralized grid?
This middleman sector is highly inefficient due to massive thermal conversion losses.
What is the Electricity Generation sector?
This end-use sector rejects the highest percentage of the total energy it receives.
What is the Transportation sector?
This nonrenewable resource is used exclusively to make electricity, feeding no other sector.
What is nuclear energy (or uranium)?
Office buildings, schools, and retail stores make up this specific end-use sector.
What is the Commercial sector?
This fossil fuel saw a massive generation spike in recent decades, largely replacing coal.
What is natural gas?
A sector with a very high ratio of "Energy Services" to "Energy Input" is called this.
What is highly efficient?
Passing through "Electricity Generation" shifts energy from a primary source to this type.
What is a secondary source?
These clean energy sources recently surpassed coal burning in the United States.
What are renewables?
Combined, these two end-use sectors consume the absolute majority of US energy. (need both sectors)
What are Transportation and Industrial?
Technologies like LEDs and smart thermostats cause this system baseline to trend upward.
What is energy efficiency?
This foundational law of thermodynamics explains why "Waste Energy" can never be completely engineered out of a system.
What is the Second Law of Thermodynamics?