In a 1 m thick wall, the temperature distribution at a given instant is T(x) = co+c1x+c2x2 where T is in 0C and x is in m. The constants are: c0 = 8000C, c1 = –2500C/m and c2 = –400C/m2. The thermal conductivity of the wall is 50 W/mK and wall area is 5 m2. If there is a heat source generating uniform volumetric heating at the rate of 500 W/m3 inside the wall, then the rate of change of energy storage in the wall, in kW, is _________