As part of its Green Building Technology (GBT) initiative, the Southern Alberta Institute of Technology (SAIT) sought to extend its applications of sustainable building practices. More specifically, it wanted to focus on the implementation of:
- Energy-efficient envelope designs.
- Renewable power sources.
- Advanced mechanical systems.
- Architectural ecology features
- Optimizations for air quality, lighting and water consumption.
The new GBT lab was designed with two purposes in mind. First, to meet the functional requirements of the department as they related to current and future research initiatives. Second, to showcase many of these new technologies.
To that end, the building's roof was built to accommodate dedicated solar photovoltaic (PV) infrastructure for SAIT. With a 45-degree slope facing south and all of its vents and penetrations facing north, it was ideal for the installation of an exemplary PV system.
Working with the GBT's architects, local solar distributors recommended all-black modules for their pleasing aesthetics, along with their numerous possible orientations and layouts. The final selected design closely followed the notched roofline of the GBT, while the array was aligned with its prominent window trims. This option prevailed over a portrait layout that would have added even more panels yet did not conform with the structure's original shape.
The energy consumption of the GBT building varies substantially depending on the specific research project undertaken at a given time. Nevertheless, it is expected the new 9-kilowatt system will suffice for all base loads in the building, thanks to its low-energy design features, such as:
- Natural daylighting.
- LED lights.
- Energy Star appliances.
- ECM pumps for the hydronic space heating system.
- Ventilation via open skylights.
- Passiv-Haus envelope design (obviating the need for air conditioning).
One of the biggest challenges in setting up solar systems is integration of modules into the building, both aesthetically and electrically. The all-black module selection efficiently addressed the visual issue, but the electrical hurdles were more extensive.
The GBT building was electrically linked to the SAIT campus via a 480-volt, 3-phase service; initial plans involved the use of an inverter with the same specifications. However, the building required an alternative inverter to match its with 208-volt, 3-phase supply. The project team opted for APS quad micro-inverters, installed on the GBT rooftop.
Since SAIT is itself a training institution (including for electricians), the project benefited from having technical instructors on-site to help with the installation of the solar PV system on the GBT. One instructor assumed a leadership role and coordinated key setup processes on evenings and during weekends.
With all hands on deck, the solar PV system was completed in time for the summer solstice on June 21. That date had been preselected for the formal opening ceremony at the GBT. Success was never assured, due to the challenges of the 45-degree roof slope as well as the inexperience of the installers (many of whom were SAIT staff) working on the project.
The black frame, backsheet and mono cell together created an 'all-black' module, meeting the preferences of the GBT's architects. These 60-cell modules were also the right size for the project.
More specifically, at 280 watts apiece, four modules can supply 1,120 watts, providing a 1:12 DC:AC ratio with the APS Y1000 inverters. The local Trina Solar distributor, National Solar Distributors, has been a strong supporter of GBT and coordinated the logistics and supplies while offering a very attractive price on services.
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