We now determine the sensitivity of the operation to energy costs.

We compute the net return as a function of time and energy rate s $/min to run the reaction.

We compute the change in net rate as a function of time.

Now we compute the difference in net return as a function of the energy price in $/min - this is the marginal change in net return as a function of energy.

There is a greater marginal loss in revenue when energy costs are low.