First Midterm Exam
Due Monday March 7rd by email or hard copy
This is a take-home exam. Answer all questions, showing work where necessary to demonstrate skills or learning, diagrams if asked or if it helps. If you don’t know or can’t work out an answer, put down what you do know. Show all work. You may research answers. You may discuss them with the instructor. You may not confer with other students. Submit by email or hard copy only. Do not submit via Canvas.
Exam is 20% of grade for class
- Calculate an RoI analysis for a residential solar PV system costing $15,000. Your client has a south-facing roof 20 feet wide by 30 feet long, pitched at 45 degrees. Specify rated power and an estimate of the actual power produced. Provide simple payback and cost effectiveness calculations, including economic profit and cost per watt. Assume net metering with CMP Standard Offer as a baseline, 10,000 kWh/year consumption, cash payment for the installation, twenty-year insured lifespan at $50/year premium, and typical Maine climate. (You may, if you wish, use an annuity model for amortized/levelized costs, but without interest charges it is not strictly necessary.)
- Calculate the gross (not the lifecycle or net) emissions savings.
- Calculate the change in cost-effectiveness if net metering is abolished and a PowerWall-type battery costing $4,000 (installed) is instead used. Assume all power produced can be used.
(See me for help if you didn’t get enough practice doing all this in class or lab.)