Defibrillator energy?
200J is not a lot of energy. For instance 200J will heat a glass of water about 0.2-0.25 kelvin. An average cellphone-battery holds about 30kJ.
When discussing electrical and electronic systems energy is commonly specified in Wh but one joule is equal to one Ws (and one Wh equals 3.6kJ since one hour is 3.6ks)