Optimum Solar Tilts for Multiple Tilt PV Mounting System

17 April 2020

Electrical and Engineering student, Janariah Ahmad Reza, has developed a tool that calculates the optimal panel tilt angle of a solar PV installation depending on climate and location.

  • Solar panel tilt angle

Janariah Ahmad Reza, a 2020 Third Pro Electrical and Electronic Engineering student (Minor in Power Engineering), completed a Callaghan Innovation’s supported summer research internship with DARC Technology and the EPECentre in February 2020.

Janariah’s main project was to optimise the tilt angle of a solar PV installation utilising a mechanical multiple tilt mounting system.  The mechanical mounting structure allows for a number of fixed PV panel mounting angles, so that the PV panel tilt can be manually changed throughout the year.  This improves irradiance capture by adjusting for seasonal changes in the solar declination angle.  In summer, when the sun is higher in the sky, lower/flatter tilt angles improve irradiance capture, whereas when the sun is lower in the sky, a steeper angle is better.  Using Python, Janariah developed a tool that calculates the optimal panel tilt angle and the best date to change the tilt angle for a specified New Zealand address.  She used two methods, the first a geometric approximation of irradiance capture assuming a clear sky model and secondly using NIWA’s typical meteorological year (TMY) climate data.  The software performed web scraping to access NIWA’s climate data, and other sites to provide address to geographic coordinate translation and elevation data.

A case study of a PV system in Waipara showed a 3% increase in irradiance capture by introducing a tilt change in autumn and spring, an additional 400kWh for a 10kW system. The addition of further tilt changes in a year provided diminishing returns.

Janariah also did a first-pass analysis of the past seven years of historical electricity spot price data to assess if there was a strong correlation between spot prices and time of day. Some evidence of increased pricing at morning and evening peaks was observed. However, what was more noticeable was the year-to-year differences in price volatility.

The final piece of work she performed, was a market review of Home Energy Management Systems (HEMS), focussing on Level 3 and 4 (Alarm and Alert and Autonomous systems) available in Australasia.

The EPECentre team was delighted to work with Janariah and wishes her the very best in her final undergraduate year and the future.