Gravimetric Energy Density
Calculator and formulas for calculating the gravimetric energy density (Specific Energy)
Gravimetric Energy Density Calculator
Calculate specific energy
Calculates the gravimetric energy density (energy per mass). Important parameter for fuels, batteries and energy carriers.
Example Calculation
Example: Lithium-Ion Battery
Problem:
A lithium-ion battery with 2 kg mass stores 720,000 J of energy. What is the gravimetric energy density?
Given:
- Mass m = 2 kg
- Energy E = 720,000 J = 720 kJ
- Find: Gravimetric energy density w
Solution:
Practical Applications
Typical Energy Densities
Fuels
- Hydrogen: 120 MJ/kg
- Gasoline: 44 MJ/kg
- Diesel: 43 MJ/kg
Batteries
- Li-Ion: 0.4-0.9 MJ/kg
- Lead-acid: 0.14 MJ/kg
- NiMH: 0.29 MJ/kg
Formulas for gravimetric energy density
The gravimetric energy density is a measure of energy per unit mass of a substance. SI unit: Joule per kilogram (J/kg). Important parameter for energy carriers and storage systems.
Calculate energy density
Basic formula for specific energy from energy and mass.
Calculate energy
Rearrangement to calculate the stored energy.
Calculate mass
Rearrangement to calculate the required mass.
Important Notes
- Gravimetric energy density is important for mobile applications (weight matters)
- Distinction between theoretical and practical energy density
- Fuels typically have higher energy densities than batteries
- Important factor for range and efficiency of vehicles
Detailed description of gravimetric energy density
Definition and Significance
This function calculates the gravimetric energy density or specific energy. The gravimetric energy density is a measure of energy per unit mass of a substance (SI unit: Joule per kilogram).
Usage Instructions
To calculate, select the value to be calculated using the radio buttons. Then enter the corresponding value and click the 'Calculate' button.
Application Areas
Energy Storage
Batteries, accumulators, capacitors, flywheel storage. Evaluation of storage capacity per unit weight.
Fuels
Gasoline, diesel, hydrogen, biomass, natural gas. Comparison of different energy carriers for transport and heating.
Vehicle Technology
E-mobility, range, weight optimization. Crucial for performance and efficiency of vehicles.
Energy Densities in Comparison
The gravimetric energy density varies greatly between different energy carriers and determines their suitability for different applications:
Very high (>40 MJ/kg)
Hydrogen: 120 MJ/kg
Gasoline: 44 MJ/kg
Diesel: 43 MJ/kg
Medium (1-40 MJ/kg)
Natural gas: 55 MJ/kg
Wood: 15 MJ/kg
Coal: 25 MJ/kg
Low (<1 MJ /kg)
Li-Ion battery: 0.4-0.9 MJ/kg
NiMH battery: 0.29 MJ/kg
Lead-acid battery: 0.14 MJ/kg
Conclusion: Fuels have significantly higher energy densities than batteries, but batteries can deliver energy directly electrically!
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