TECH/ENVS 305 – Green Technologies

Homework #1

Submit one Excel file for the following question. (Make sure each graph has the question part in the title)

Q1) Investigate the effect array tilt and tracking has on energy production from a solar array.

You must use PVWatts to complete answer this question. Available here http://pvwatts.nrel.gov

Steps for All Cases

  • Input zip code 60115 Click “Go”
  • Input 2.8 in DC System Size (roughly equal to the electric demand of the average U.S. home)
  • Leave Module Type as standard and System Losses at 14.08%
  • Leave Array Azimuth at 180 (standard practice for the northern hemisphere)
  • Change Array Type and Tilt according to question part
  • Click the orange arrow to go to PVWatts results
  1. (*) Plot in Excel, the monthly AC energy produced from a 2.8 kW array with a fixed (roof mount) array type with a tilt equal to the latitude of the location (41.9o) (Yearly Optimized).
  2. Plot in Excel, the (Summer Optimized)monthly energy produced from a 2.8 kW array with a fixed tilt  = (0.93 * (local latitude)) – 21
  3. Plot in Excel, the (Winter Optimized) monthly energy produced from a 2.8 kW array with a fixed tilt = (0.875 * (local latitude)) + 19.2
  4. Plot in Excel, the monthly energy produced from a 2.8 kW array with a summer optimized tilt for March thru September and a winter optimized October thru February (Seasonal Optimized).
  5. Plot in Excel, the monthly energy produced from a 2.8 kW array with a 1 axis track and a fixed tilt equal to the latitude of the location.
  6. Plot in Excel, the monthly energy produced from a 2.8 kW array with a 2 axis track and a fixed tilt equal to the latitude of the location.
  7. Calculate the annual total kWh difference between in a & b and a & c.
  1. Fill in the provided table with the differences between annual energy production for the four types of systems (e.g. 1 Axis Annual AC production – Yearly Optimized Annual AC production)