5. Mary needs a new roof for her home. She is comparing the cost of a solar roof vs. traditional shingles. Currently she is paying $1800/yr for energy and does not foresee price increases. She plans to live in her home indefinitely. Based on the costs below at an interest rate of 10%, which roof do you recommend? Justify your answer. 1st Cost www Annual Energy Savings Useful Life Shady Solar Panels $10,000 30% (1+0.016) 8 years Hot-Stuff Solar Panels $20,000 80%(1+0.026) 15 years Old Timer's Shingles $25,000 25 years