Conversion of electrical units (Capacitance) into energy and power units
Symbols used in this notes are: F – Faraday; C – Coulomb; V – Volt; A – Ampere; J –Joules; s – second; W – Watt; g – gram; h – hour Correlation between electrical (capacitance) and energy and power units F = C/V W = A×V C = A×s J = W×s (Energy unit) F = A×s/V So, F×(V^2) = A×s×V = W×s = J Capacitance is expressed in, F Energy is expressed in, Wh Power is expressed in, W Specific Capacitance is expressed as: F/kg (or) F/g Specific Energy is expressed as: Wh/kg (or) Wh/g Specific Power is expressed as: W/kg (or) W/g Assume a supercapacitor has a Specific Capacitance of 2000 F/g and discharges at a potential difference of 1 V in 900 s, then Specific Energy and Specific Power is related to its Specific Capacitance as: Formula: Specific energy = 0.5 × Specific Capacitance × (dV)^2 Here, Specific Capacitance = 2000 F/g and dV = 1 V = 0.5 × 2000 F/g × (1 V)^2 = 1000 F/g V^2 = 1000 J/g = 1000 W×s /g = {1000 W×s /