are derived from sunlight, they are considered primary energy sources which are extracted from the earth (fossil fuels). Natural uranium is also a primary energy source extracted from the earth but does not come from the decomposition of organisms (mineral fuel). See also Capital goods Coefficient of performance Embedded energy Energy and society Energy crisis Energy pay-back Energy resource Energy source Energy storage Energyware Entropy Exergy Future energy development Hydrogen economy ISO 14000 Liquid nitrogen economy Lithium economy Methanol economy Renewable resource Vegetable oil economy Renewable Energy References Further reading European Nuclear Society info pool/glossary: Energy carrier Our Energy Futures glossary: Energy Carriers Störungsdienst, Elektriker (in German) External links "Boron: a better energy carrier than hydrogen?" paper by Graham Cowan ISO 13600 Technical energy systems -- Basic concepts: gives the basic concepts needed to define and describe technical energy systems. Energetics Energy storage Thermodynamics Hydrogen production