Bringing The Power Source of the Stars Down to Earth

Energy Sources & Conversion

An Overview of Energy Conversion Processes

One of the fundamental principles of physics is the conservation of energy. Energy can take on many forms, and various processes convert one form into another. Thermodynamics governs these conversions. While total energy always remains the same, after most conversion processes the amount of useful energy remaining is reduced.

Energy conversion graphic
not loaded.

The processes which convert energy into useful forms have limited thermodynamic efficiencies, typically only 10-40%. This means that typically 60-90% of the input energy becomes waste energy. Often significant waste materials are also produced.


Energy-Releasing Reactions

Chemical Fission Fusion
Sample Reaction C + O2 -> CO2 n + U-235 -> Ba-143 + Kr-91 + 2 n H-2 + H-3 -> He-4 + n
Typical Inputs (to Power Plant) Bituminous Coal UO2 (3% U-235 + 97% U-238) Deuterium & Lithium
Typical Reaction Temperature (K) 700 1000 108
Energy Released per kg of Fuel (J/kg) 3.3 x 107 2.1 x 1012 3.4 x 1014


More Information:

Page originally created by students Jason Edson and Hannah Cohen.


CPEP grants permission for teachers and students to reproduce these copyrighted images and materials for their personal or classroom use, provided is cited as the source. For other CPEP copyright permissions, email


Lawrence Livermore National Laboratory Princeton Plasma Physics Laboratory | About Us | Privacy & Legal Notice | Contact | UCRL-MI-137188