Research Axes - Axis 2

Research Axis 2: Building flexibility for enhanced integration of distributed renewable energy resources and smart grid interaction

This axis will emphasize utilization of the energy flexibility of buildings through proper modelling and integration of thermal storage (building-integrated or in the HVAC) and development of advanced multifunctional building envelope systems that combine several functions in order to reduce cost while maximizing energy efficiency, such as fenestration systems that integrate semitransparent photovoltaic layers that generate electricity while transmitting daylight and also possibly producing useful heat. Windows will include integrated motorized shading. Retrofit systems will particularly be considered. The work will involve testing and simulation of the potential energy performance of different roof and façade concepts that optimize solar energy utilization by harnessing nearly the full spectrum of sunlight to generate electricity, transmit part as daylight and much of the remainder as useful heat. The challenge with solar cells is to avoid their overheating and to utilize the heat collected both with passive and active measures, while rejecting it when the building is in cooling mode. Promising configurations will be studied through integrated energy simulations using thermal network models, coupled with electricity generation models for photovoltaics and daylighting models based on ray tracing and radiosity techniques.

Project 2.1 Building design to support energy flexibility, including occupant behavior

B. Lee; Collaborators: F. Laurencelle (HQ); HQP: 1 PhD, 2 MASc, 1PDF

Energy flexibility allows the possibility of modifying building electricity demand profile through optimizing building operation. With the increasing adoption of distributed renewables energy flexibility could be enhanced through proper implementation of demand response and MPC. Key challenges are occupant related issues, such as the use of a typical schedule rather than a probabilistic model of occupant behavior, which leads to energy demand prediction that is far from reality. With the relatively long lifespan of buildings, not just the diverse occupant behavior but also the foreseeable changes in space utilization introduces further uncertainty in the evaluation.

Project 2.2 Study of integration of semitransparent photovoltaics into building envelope

Collaborators: Jonathan (HQ); H. Ge, HQP: 1PDF, 1 PhD, 1 MASc

This project will investigate integration of semitransparent photovoltaics (STPV) into windows and building envelopes in general both in retrofits and new buildings. A STPV window can generate electricity while transmitting daylight and having all other functions of a window. With double facades (e.g. BIPV/T) heat can also be harnessed.

A methodology for systematic comparison of retrofit design options will be developed while taking into account the representative buildings and their generalization into archetypes. The most promising options identified through simulation will be studied experimentally in the SSEC facility by replacing the façade of the new test-room in Figure 3a.

Project 2.3 Comparison of different types of building-integrated storage and isolated storage charging/discharging options for building flexibility

Collaborators: K. Lavigne (HQ), J. Tamasauskas (CanmetENERGY); HQP: 1 PhD, 1 MASc, 1PDF

Volatility of renewables represents a challenge for their integration to the grid. Thermal storage can be used to address this challenge and ensure flexibility of the building, enabling it to respond to grid signals. This project, closely linked to Axis 1, will address different types of storage such as thermo-active building systems (TABS), PCM panels on walls, storage heaters and isolated storage and a combination of those technologies. The test-room mentioned above will allow the following strategies to be studied and compared to maximize the use of renewables and to mitigate for electric utility functions:

Experiments in the environmental chamber will be performed for typical sequences of simulated daily weather profiles under a variety of conditions (e.g. sunny-hot and cloudy-hot). The energy flexibility of the different types of storages will be quantified.

Project 2.4 Characterization of the impact of short term solar radiation fluctuations on building power demand in heating conditions

Collaborators: F. Laurencelle (HQ), M. Fournier (HQ), TBD (Concordia); HQP: 1 MASc, 1 PhD

This project consists in evaluating the impact of the solar radiation fluctuations on the heating load of a PV equipped low-mass building (typically a new or retrofitted house), during cold days of variable cloudiness. The emphasis will be on short term transient impacts (time response, instant power generation and demand, energy balance, heating energy storage). The impact in term of heating power demand will be connected to the window size and orientation, the building thermal mass, the thermostat dead band and the type of heating system, within a parametric study. A parametric model of these short term phenomena will be developed. It will focus on the relationship between the transient solar radiation and the power demand of the house.

Project 2.5 Methodology for addressing power demand variations due to short term solar radiation fluctuations

Collaborators: F. Laurencelle (HQ), M. Fournier (HQ), H. Nouanegue (HQ)]; HQP: 1 MASc, 1 PhD

Cloud cover affects both HVAC loads and PV output. In heating conditions, both these effects would increase the variations in power demand, as characterized in Project 2.4. Mitigation solutions to smooth these variations are the scope of this project.

Axis Links: Axis 1, Axis 2 and Axis 3.