kW to joules calculation formula
E(J) = 1000 x P(kW) × t(s)
The energy E in joules (J) is equal to 1000, multiplied by the power P in kilowatts (kW), multiplied by the time period t in seconds (s).
J = 1000 x kW x s
joule = 1000 x kilowatt x second
Power (P) = 2,5kW
Time period = 5 seconds
Energy (E) = 1000 x 2,5kW x 5s = 12500J