Part D The bar graph shows the cost per megawatt-hour comparison of various renewable and nonrenewable energy sources in the United States. The blue portion of the bars represents the cost of electricity. The red portion represents the additional system costs of harnessing that type of energy. Systems costs may include equipment expenses and costs of connection to a power grid. Based on the graph, compare and contrast the total cost of renewable and nonrenewable energy sources. Explain what might account for the differences in cost. Do additional research as necessary.