Problem
The 1920’s Inglis Building, at the Department of Engineering, has an archetypal saw-tooth roof with north-facing window lights. Prior to 2013 the roof began to leak and so was very much in need of routine maintenance.
Solution
Instead of just patching up the leaking roof, the Department of Engineering used this opportunity to explore different energy saving options through research. An undergraduate summer placement looked at modelling the fabric of the building. This provided recommendations for insulation improvements. Alongside this solar photovoltaic (PV) panels were installed on the south-facing slopes. The brick chimney at the top of the Inglis building provided a problem for the installation of PV panels, due to the shadow it cast over the roof. An Engineering PhD student, Canston Urayai, carried out some analysis and modelling in order to inform the best panels to install and in what orientation.
Based on what they learned from their students' detailed modelling, the department opted for a PV panel produced by Viridian Solar.
Installed in 2013, the energy roof has a mixture of string and micro-inverters. The micro-inverters generate slightly less power but are better at generating under shadow-cast conditions.
“The micro-inverter includes thin-film technology that our Electrical Engineering Division's been involved in, so there's a nice link between our teaching and research and the commercial products that have benefited from the work we've done here.” David Green, Dept. of Engineering
Impact
In the year following its installation, phase 1 of the energy roof on the Inglis Building generated 82,471 kWh, around 3% of the building's total energy use. As well as saving energy and carbon, the energy roof is providing important opportunities for the department's teaching and research, which in turn are helping inform decisions about similar projects elsewhere in the University.
The department is using the energy roof to form part of the third year undergraduate renewable energy course. The Environment and Energy section’s Living Laboratory project funded the software needed in order for students to model the installation and also think about the application of this to other University buildings.