Second Generation Photovoltaic Prototype
Toronto Grid – Sunlight Studies
Denegri Bessai Studio – in collaboration with Internat Energy Solutions Canada (IESC) and the support of the Design Industry Advisory Committee (DIAC) – put together comprehensive research required for the design and implementation of a multi-functional building-integrated photo voltaic (BIVP) system for multi-storey buildings in Ontario.
This project’s objective is to develop and commercialize a multifunctional building-integrated photovoltaic (BIPV) glazing design as a more energy efficient substitute for standard glazing in new building construction or as a retrofit of existing structures. The BIPV glass panel will minimize heat transfer to the external environment when not desired, block undesired solar gains (but still transmit visible light) and finally produce an electrical load that can be used within the building or introduced to the power grid.
Three Building types were identified as useful case studies for this report: a commercial office tower, a residential condominium tower, and a mid-rise institutional building. These urban building types represent the likely market for IESC’s BIPV application in the coming years.
This diagram illustrates the structural systems typical of each of the three building types studied here. Steel columns have a high strength to width ratio meaning they are an efficient use of space for commercial construction. They are often used in open commercial floor plans encased in a noncombustible material. Concrete columns contain steel reinforcement. They are also common in open floor plans. Columns are not sufficient to resist the lateral forces on a building. High rise construction can use bracing or concrete cores. Concrete cores are common because they fulfill the dual purpose of structural diaphragm and elevator shaft or emergency exit stairwell. Vertical runs for utilities, mechanical, and electrical equipment are most conveniently located within these core shear walls.
Energy is captured on the building façade via the PV modules and arrays embedded in the glazing units. It is sent as Direct Current through internal conduit to power inverters located in or adjacent to the building core on every floor or second floor of the building, where it is converted to Alternating Current, Research and interviews uncovered several options for the output of this energy. (Ministry of Energy, Ontario Government, Ontario Power Authority, PWC)
Energy harvested from the Building Integrated PV panels must be converted from DC to AC at an inverter room so that it may be available for common usages. Once it is converted to alternating current there are three options for its use:
1. Storage for later use in the building. This would require significant space demand for a storage unit.
2. Release back into the grid for net metering.
3. Redirection to other building systems.
Installation of the window wall or curtain wall system in all of the 3 building type case studies that we have identified share the common feature that they are installed at an early stage in the construction process. Once the building core, columns and floor plates are in place, the perimeter cladding- the building envelope- is installed. At this point in the construction workflow, there are no HVAC or electrical systems or specialists on the job site. The curtain wall/ window wall installation is strictly a mechanical installation whereby the envelope components, whether unitized or assembled in place, are bolted to the perimeter of the building.
To install a unitized curtain wall, each unit is lowered down from a pulley system or mechanical device temporarily installed on a girder that is is secured to the structure of the floor a few storeys above. The team situates themselves on the interior of the floor plate to receive the unit. Steel fasteners should already be in place. The glazing system is applied one floor at a time beginning with the ground floor.
First Generation BIPV Grazing Module Elevation and Section Detail (IESC)
Building Types and Their Structural Composition
BIPV Energy Path Diagram
Stick Frame Curtain Wall Installation
Unitized Curtain Wall Installation