Solar Radiation, Orbital Distance, Air Pressure, and the Abundance of water.
The energy stored in a capacitor is
E = (1/2) · (capacitance) · (voltage)²
E = (1/2) · (6 x 10⁻⁶ F) · (12 V)²
E = (3 x 10⁻⁶ F) · (144 V²)
<em>E = 4.32 x 10⁻⁴ Joule</em>
(That's 0.000432 of a Joule)