(Lac-Mégantic) In this building used by firefighters, a ladder leads to the top of the building. Exiting through the hatch that leads to the roof, you find yourself in a small sea of solar panels – 144 dark patches shimmering even on an overcast day.
These are bifacial panels, the first in Lac-Mégantic, underlines Mathieu Pépin, project manager in energy transition at the City of Lac-Mégantic.
If the roof membrane is clear, it is not only to avoid creating a heat island. It reflects the sun’s rays, which thus strike the underside of the panels, which also generate electricity. Compared to traditional monofacial panels, of which only the upper side can be activated, “efficiency is improved by around 30%,” explains Mr. Pépin.
One floor below, in a small room resembling a server room, batteries store this energy captured from the sky.
PHOTO ROBERT SKINNER, THE PRESS
The barracks energy management, control and storage system.
If such a system combining solar panels and batteries strikes the imagination, it is not the most profitable measure in the Quebec context, specifies the specialist in energy transition. “The cost of electricity is so low that we can speak of a return on investment of more than 15 years on the solar panel [alors que] its service life is 15 to 20 years. »
Energetic efficiency
To increase energy efficiency, the first step is to enhance the building envelope. “The best energy saving is the energy that is not consumed. The better the insulation, the less we need to heat the premises”, illustrates Mr. Pépin, drawing our attention to the thickness of the walls.
PHOTO ROBERT SKINNER, THE PRESS
The energy transition project manager at the City of Lac-Mégantic, Mathieu Pépin, in front of the solar panels of the new fire station
The mechanics of this building also contribute to its performance. The large garage is equipped with a radiant floor. “It enhances the feeling of warmth and even allows it to be lowered a bit without feeling less comfortable. »
A heat recovery system and heat pumps also reduce the amount of energy required to temper the fresh air brought in from outside to ventilate the building. Control systems also help to manage power demands (energy consumption at specific times), which have an impact on billing.
Compared to a building meeting the minimum requirements, this barracks could consume up to 20% less energy, and the electricity bill would be reduced by several thousand dollars per year, suggest preliminary estimates.
As for its solar energy production, it would reach 82.35 megawatt hours (MWh) per year, with a monthly peak of 9.6 MWh in July.
PHOTO ROBERT SKINNER, THE PRESS
The garage, whose opening doors cause significant heat loss, is equipped with a radiant floor.
Connected to the microgrid
This fire station is the most recent addition to the electrical microgrid in downtown Lac-Mégantic, commissioned by Hydro-Québec at the end of 2020. This project includes some thirty buildings topped with some 2,200 solar panels, including approximately 1,700 on the roof of the sports center.
This high-rise solar park totals nearly 800 kW of installed power, plus a storage system that can store around 700 kWh. All this energy contributes to supplying the buildings and installations connected to the microgrid, including the urban lighting located inside the perimeter.
PHOTO ROBERT SKINNER, THE PRESS
The new Lac-Mégantic fire station, inaugurated in the spring.
Even in rainy weather, solar provides up to 31% of the energy consumed by buildings on the network, we could see on the real-time data screen installed in the city center. In good summer weather, it can reach 100%.
In the week preceding our visit, at the beginning of June, “there were two fine days when we were in an islanding operation, therefore completely disconnected from the main Hydro-Québec network,” enthuses Mr. Pépin.
PHOTO ROBERT SKINNER, THE PRESS
Commemorative plaque installed on a wall of the new fire station paying tribute to the firefighters who fought the tragic fire caused by the derailment of an oil train in 2013.
Through one of the windows of the barracks, he shows us a powerful 180 kW terminal for electric vehicles, near the old station. A fast charging station also connected to the microgrid.
“So when you’re islanding, you can say that the energy you put into your car comes from the sun. I think it’s great ! exclaims the project manager.
Hydro-Québec’s Electric Circuit has only about twenty of these 180 kW charging stations throughout the province. And Lac-Mégantic was the third city to have one, after Trois-Rivières and Stoneham, in the Quebec region.
“We, in the depths of Quebec, have just proved that you can go without any problem. It is a strong symbol! »