| Storage type | Energy density by mass (MJ/kg) | Energy density by volume | Peak recovery efficiency % | Practical Recovery Efficiency % |
|---|
Mass-energy equivalence | 89,876,000,000 | | | |
| Binding energy of Helium-4 nucleus | 683,000,000 | 857,000,000,000,000,000,000,000 (8.57x1024) | | |
| Nuclear fusion of hydrogen (energy from the sun) | 645,000,000 | | |
| Deuterium-Tritium fusion | 337,000,000 | | | |
| Nuclear fission (of 100% U-235) (Used in nuclear power plants) | 88,250,000 | 1,500,000,000 | |
| Natural uranium (99.3% U238, 0.7% U235) in fast breeder reactor | 24,000,000 | | | 50% |
| Enriched uranium (3.5% U235) in light water reactor | 3,456,000 | 30% |
| Hf-178m2 isomer | 1,326,000 | 17,649,060 | | | |
| Natural uranium (0.7% U235) in light water reactor | 443,000 | 30% | |
| Ta-180m isomer | 41,340 | 689,964 | | |
| Specific orbital energy of Low Earth orbit | 33 (approx.) | | |
| Cl2O7 + CH4 - computed | 17.4 | | |
| Cl2O7 decomposition - computed | 12.2 | | |
| Nitromethane | 11.3 | 12.9 | | |
| Octanitrocubane explosive - computed | 8.5 | 17 | | |
| Tetranitrotetrahedrane explosive - computed | 8.3 | | |
| Heptanitrocubane explosive - computed | 8.2 | | |
| Dinitroacetylene explosive - computed | 7.9 | | |
| Sodium (reacted with chlorine) | 7.0349 | | |
| Tetranitrocubane explosive - computed | 6.95 | | |
| Ammonal (Al+NH4NO3 oxidizer) | 6.9 | 12.7 | | |
| Tetranitromethane + hydrazine bipropellant - computed | 6.6 | | |
| Hexanitrobenzene explosive - computed | 6.5 | | |
| Octogen explosive - computed | 6.3 | | |
| ANFO-ANNM | 6.26 | | |
| TNTin Kinney, G.F.; K.J. Graham (1985). Explosive shocks in air. Springer-Verlag. ISBN 3-540-15147-8. | 4.610 | 6.92 | | |
| Copper Thermite (Al + CuO as oxidizer) | 4.13 | 20.9 | | |
| Thermite (powder Al + Fe2O3 as oxidizer) | 4.00 | 18.4 | | |
| Hydrogen peroxide decomposition (as monopropellant) | 2.7 | 3.8 | | |
| Lithium ion battery with nanowires | 25.42.54-2.72? | 29 | 95% |
| Lithium thionyl chloride battery | 2.5 | |
| Water 220.64 bar, 373.8°C | 1.968 | 0.708 | |
| Kinetic energy penetrator | 1.91.9-3.4 | 3030-54 | |
| Fluoride ion battery | 1.71.7-(?) | 2.8(?)2.8(?) | |
| Regenerative Fuel Cell (fuel cell with internal Hydrogen reservoir used much as a battery) | 1.62 sm=n | |
| Hydrazine(toxic) decomposition (as monopropellant) | 1.6 | 1.6 | |
| Ammonium nitrate decomposition (as monopropellant) | 1.4 | 2.5 | |
| Zinc-air battery | 1.33 | |
| Capacitor by EEStor (claimed prototype capacity) | 1.0 | 2.18 | |
| Thermal energy storage(Molten Salt) | 11 approx. | |
| Molecular spring | 11 approx. | |
| Sodium-sulfur battery | 1.23 | 85% |
| Liquid nitrogen | 0.77 | 0.62 | |
| Lithium ion battery | 0.540.54–0.72 | 0.90.9–1.9 | 95% |
| Lithium sulphur battery | 0.540.54-1.44 | |
| compressed air at 300 bar (at 12°C), without container | 0.512 | 0.16 | |
| Flywheel | 0.5 | 1-0.15%/10s |
| 5.56 × 45 mm NATO bullet | 0.40.4-0.8 | 3.23.2-6.4 | |
| Zn-air batteries | 0.40.40 to 1.7 | 5.95.9 | |
| Ice(Ice) | 0.335 | 0.335 | |
| Zinc-bromine flow battery | 0.270.27–0.306 | |
| Compressed air at 20 bar (at 12°C), without container | 0.27 | 0.01 | 64% |
| NiMH Battery | 0.22 |
| NiCd Battery | 0.140.14-0.22 | 80% |
| Lead acid battery | 0.090.09–0.11 |
| Compressed air in fiber-wound bottle at 200 bar (at 24°C) | 0.14 | 0.06 | |
| Vanadium redox battery | 0.09 | 0.1188 | 7070-75% |
| Vanadium bromide redox battery | 0.18 | 0.252 | 81% |
| compressed air in steel bottle at 200 bar (at 24°C) | 0.04 | 0.1 | |
| Capacitor Ultracapacitor | 0.0206 | 0.050 | |
| Capacitor Supercapacitor | 0.01 | 98.5% | 90% |
| Capacitor | 0.002 | |
| Water at 100 m dam height | 0.001 | 0.001 | 8585-90% |
| Spring power (clock spring), torsion spring | 0.0003 | 0.0006 | |
| Liquid hydrogenclarification needed | 143 | 10.1 | |
| Compressed gaseous hydrogen at 700 bar clarification needed | 143 | 5.6 | |
| Gaseous hydrogen at room temperaturecitation needed | 143 | 0.01079 | |
| Beryllium (toxic) (burned in air) | 67.6 | 125.1 | |
| Lithium borohydride (burned in air) | 65.2 | 43.4 | |
| Boron (burned in air) | 58.9 | 137.8 | |
| Methane (1.013bar, 15°C) (burned in air) | 55.6 | 0.0378 | |
| Natural gas (burned in air) | 53.6 | 10 | |
| LPG propane (burned in air) | 49.6 | 25.3 | |
| LPG butane (burned in air) | 49.1 | 27.7 | |
| Gasoline | 46.4 | 34.2 | |
| Diesel fuel/residential heating oil (burned in air) | 46.2 | 37.3 | |
| Polyethylene plastic | 46.3 | 42.6 | |
| Polypropylene plastic | 46.4 | 41.7 | |
| Gasohol E10 (10% ethanol 90% gasoline by volume) | 43.54 | 33.72 | |
| Gasohol E85 (85% ethanol 10% gasoline by volume) | 33.1 | 25.65 | |
| Lithium (burned in air) | 43.1 | 23.0 | |
| Jet A aviation fuel / kerosene | 42.8 | 33 | |
| Biodiesel oil (vegetable oil) | 42.20 | 33 | |
| DMF (2,5-dimethylfuran) | 42 | 37.8 | |
| Crude oil (according to the definition of ton of oil equivalent)clarification needed | 46.3 | 37 | |
| Polystyrene plastic | 41.4 | 43.5 | |
| Body fat metabolism | 38 | 35 | 2222-26% | |
| Butanol | 36.6 | 29.2 | |
| Graphite (burned in air) | 32.7 | 72.9 | |
| coal Anthracite | 32.5 | 72.4 | 3636% |
| Silicon (burned in air) | 32.2 | 75.1 | |
| Aluminum (burned in air) | 31.0 | 83.8 | |
| Ethanol | 30 | 24 | |
| Polyester plastic | 26.0 | 35.6 | |
| Magnesium (burned in air) | 24.7 | 43.0 | |
| coal Bituminous | 24 | 20 | |
| PET plastic | 23.5 (impure) | |
| Methanol | 19.7 | 15.6 | |
| Hydrazine (toxic) combusted to N2+H2O | 19.5 | 19.3 | |
| Liquid ammonia (combusted to N2+H2O) | 18.6 | 11.5 | |
| PVC plastic (improper combustion toxic)clarification needed | 18.0 | 25.2 | |
| Sugars, carbohydrates & protein metabolism | 17 | 26.2(dextrose) | 2222-26% | |
| coal Lignitecitation needed | 14.0 (to 19) | |
| Calcium (burned in air)citation needed | 15.9 | 24.6 | |
| Glucose | 15.55 | 23.9 | |
| Dry cowdung and cameldung | 15.5 | |
| Wood | 6.0 (to 17) | |
| Sodium (burned to wet sodium hydroxide) | 13.3 | 12.8 | |
| Household waste | 8.0 (to 11) | |
| Sodium (burned to dry sodium oxide) | 9.1 | 8.8 | |
| Zinc (burned in air) | 5.3 | 38.0 | |
| Teflon plastic (combustion toxic, but flame retardant) | 5.1 | 11.2 | |
| iron (burned to iron(III) oxide) | 5.2 | 40.68 | |
| iron (burned to iron(II) oxide) | 4.9 | 38.2 | |