Chapter 12, Problem 1P

To determine

North Carolina to utilize the wave energy for all of its electricity would it is reasonable?

Explanation of Solution

Given information:

The total annual per capita electricity requirement is $15{\text{MWh}}_{\text{c}}$.

The coastline used wave electricity generation is 5%.

The average efficiency is 20%.

Calculation:

Refer Figure 12.1 in the textbook,

For North Carolina, the wave power is 33 kW/m.

Find the total wave power in the coastline:

$\begin{array}{c}\text{Total wave power}=\left(\text{Coastline}\text{used}\times \text{Total}\text{length}\text{of}\text{coastline}\right)\times \text{Wave}\text{power}\\ =\left(\text{0}\text{.05}\times \left(\text{500}\text{km}\times \text{1000}\right)\text{m}\right)\times \text{33}\text{kWh/m}\\ =8.25\times {10}^8\text{W}\end{array}$

Find the total energy available per year:

$\begin{array}{c}\text{Total energy available per year}=\text{Total wave power}\times \text{Average}\text{efficiency}\\ =8.25\times {10}^8\text{W}\times 0.2\\ =165,000,000{\text{Wh}}_{\text{c}}\text{/h}\times \text{8,760}\text{h/y}\\ =1.45\times {10}^{12}{\text{Wh}}_{\text{c}}\text{/y}\end{array}$

Consider the population of North Carolina is $9.53\times {10}^6$.

Find the total annual electricity for the state:

$\begin{array}{c}\text{Total annual electricity for the state}=\text{Annual per capita electricity requirement}\times \text{Population}\\ =\left(15{\text{MWh}}_{\text{c}}\times {10}^6\right){\text{Wh}}_{\text{c}}\times 9.53\times {10}^6\\ =1.43\times {10}^{14}{\text{Wh}}_{\text{c}}\end{array}$

Compared to this total requirement, the wave energy is about 1%. Other sustainable energy approaches may be more benefecial.