The electricity Quebecers consume is clean… well, almost. A tiny fraction comes from the thermal power stations serving communities that are too remote to be connected to the main power grid. The involvement of CIMA+, in partnership with TCI, STACE and Smarter Grid Solutions, in a microgrid project for some thirty buildings in downtown Lac-Mégantic may well spell the end of these greenhouse gas emitting facilities.
The initiative allowed the consulting engineering firm to take home top honours in the energy category at the most recent Grands Prix du génie-conseil Québécois held in September. This is the first time that solar panels, storage systems and tools for managing energy consumption were integrated across an entire neighbourhood in Quebec. “From the outset, the project was designed as a technology showcase. The knowledge gained will be used to decarbonize diesel-powered off-grid systems,” asserts Jean-François Veilleux, smart grids and renewable energy project manager at CIMA+.
A highly complex process
It may seem straightforward, but connecting an off-grid system to Hydro-Québec’s main grid poses enormous technical challenges. The government corporation normally manages its electricity production based on demand using the water stored in its hydroelectric dams, and then distributes it throughout the province. With the Lac-Mégantic microgrid, the electricity is instead generated in a decentralized manner, locally and in a closed-circuit system, by 2,200 solar panels made by Quebec company STACE – with an installed capacity of 800 kW. However, as the sun doesn’t shine around the clock, the microgrid also needs to be able to connect to the main grid to meet the demand, and vice versa.
“If the microgrid generates 500 kilowatts while local demand is only 300 kilowatts, what do we do with the surplus? How do we store it?” asks the engineer who served as senior project manager on this collaboration between Hydro-Québec and Quebec consulting engineering firm WSP. Answering these questions means examining the option of storing electricity in batteries. “We can disconnect from the main grid and operate independently for several hours in islanded mode. The electricity then comes entirely from the solar panels and batteries,” he explains. These batteries are capable of storing approximately 600 kWh of energy. They were supplied by EVLO, a subsidiary of Hydro-Québec, and allow bidirectional energy exchanges between the microgrid and Hydro-Québec’s main grid.
Furthermore, the microgrid control system developed to manage the microgrid’s energy consumption and production has to be synchronized with Hydro-Québec’s pre-existing control systems. The key is simplicity in order to minimize potential human operating errors. “There’s a ‘master’ controller which sends commands to the control systems located in the various buildings,” Jean-François Veilleux points out. “In return, they report back on the electrical power needs of the occupants and their individual production capacities.” The goal is to ensure that everything is completely transparent to customers. The integration of this control system was carried out in partnership with Smarter Grid Solutions.
A living laboratory
The people of Lac-Mégantic can but reap the benefits of this living laboratory. Severely affected by the rail disaster in 2013, which claimed the lives of 47 residents as well as disfiguring the city centre, the local community turned the microgrid project into a symbol of its transition towards a sustainable energy future for generations to come. A multifunctional solar shelter installed at the very heart of an interpretation walkway is a significant legacy for the town. The architectural pavilion showcasing the photovoltaic technology used in the project is surmounted by 72 solar panels. It also features a display panel which provides the microgrid’s energy data in real time.
“Thanks to this project, Lac-Mégantic is now synonymous with innovation and engagement rather than tragedy,” Jean-François Veilleux, who took advantage of this engineering, procurement, construction management and commissioning contract to train young engineers on the technologies of tomorrow, is pleased to say. At the same time, CIMA+ is garnering valuable expertise for similar projects, which are likely to increase in number in Quebec as well as everywhere else in the world. “It also has an added bonus for recruiting; the employees who worked on the project speak in such glowing terms about it,” he says. “They’re our best ambassadors!”
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