Total Accumulation from a Rate Function

The rate at which a power plant generates electricity is modeled by the function $r(t) = 22 + 10\sin\bigl(\tfrac{\pi t}{48}\bigr)$, where $r(t)$ is measured in megawatts per hour and $t$ is the number of hours after operation begins. To the nearest megawatt-hour, what is the total amount of electricity generated from time $t = 0$ to $t = 72$ hours?