When you walk through the sunny atrium of the Edmonton Convention Center or spot the spectacular sloping roof of the Varennes Library on the outskirts of Montreal, it’s not obvious these buildings generate electricity. After all, none of the traditional solar panels have been nailed to the roof.
But the atrium’s semi-transparent skylights and sloped roof shingles are more than just protection from the elements – they’re Building Integrated Photovoltaic (BIPV) systems. That is, they are made of solar panels.
It is a solution touted by Elon Musk, CEO of Tesla, who started selling solar tiles in the United States in 2017. Since then, a range of made in Canada options for different parts of buildings have appeared on the market and installations have sprung up across the country to show what is possible.
Here’s a closer look at how BIPV differs from traditional solar panels and why many more could be part of the buildings of the future.
What is building-integrated photovoltaics?
While traditional solar panels are attached to buildings, BIPVs are built in the exterior as key elements.
They can be anything that is exposed to the sun: shingles, windows, siding, dormers, pergolas, balcony railings. One company, Mitrex of Toronto, is even considering using them to build greenhouses and noise barriers on highways.
BIPV systems are like other solar panels in that they generate clean energy that can be used for back-up power or sold to the grid. But they have to be designed differently to perform other functions, like shielding from wind and rain or letting in natural light.
For this reason, BIPV panels are available in a wider variety of shapes, sizes, colors and transparencies.
Why could you use BIPV instead of installing traditional solar panels?
They increase the space or surface available to produce solar energy.
Finding the space to install traditional solar panels can be difficult in places like cities. Meanwhile, “there is so much unused glass area on downtown skyscrapers and building walls and windows,” said Adam Yereniuk, COO of Kuby Renewable Energy, the company behind the installation of the BIPV in the Edmonton convention center, the largest in Canada, with a capacity of 169 kW.
The company also worked on a five-story residence at Red Deer College that is covered with solar glass siding on three sides – 545 panels in total.
BIPVs can simplify installation and potentially save costs.
PV Technical Services, based in St. George-Brant County, Ontario, has been installing traditional solar panels for over a decade. Co-founder Katherine Zhou said clients have started asking why they have to hire a contractor to re-roof their house first and another to install the racks and panels on top, especially since the penetration of the roof required for the installation of the panels void the roof warranty.
So the company developed its own solar shingle in 2016. Now, at a cost that Zhou estimates to be similar to that of a metal roof installation, his company can install solar shingles that protect the roof from the elements and generate heat. electricity. “It avoids a lot of headaches,” she said.
They can potentially outlast traditional building materials.
Andreas Athienitis, a researcher at Concordia University in Montreal who studies BIPV, said that while asphalt shingles typically last around 15 years, solar panels can last 30 years, with only a slight decrease in efficiency. (Many solar shingle systems, like the one in PV Engineering, are “smart” and allow you to monitor and replace individual shingles, if necessary.)
They can potentially generate heat as well as electricity.
At the Varennes library, outside air drawn into the ventilation system is preheated by solar panels before entering the building (which also has a geothermal heating system), Athienitis said. It also cools the panels, which don’t generate as much energy when they’re too hot.
A heat pump can potentially be added to increase the amount of space and water heating the panels can do, and the amount of energy per area that the system can deliver as a whole.
They can replace materials with a higher carbon footprint.
Mitrex is a Toronto-based company that manufactures BIPV coatings and plans to manufacture highway noise barriers. These are two things that are often made of concrete, which has a higher carbon footprint than BIPV glass and silicon panels.
“So we take carbon [out of the] system just by installing it, ”said company CEO Danial Hadizadeh. Over time, he added, the renewable energy generated by the BIPV panels will offset the emissions used to manufacture them in the first place.
They have a unique look.
BIPV is making a visual statement, Yereniuk said.
“If you’ve walked through the Edmonton Convention Center, you can see for yourself that it creates something amazing that you can’t get with any other standard drink.
Can they produce as much electricity as traditional solar panels?
Their effectiveness depends on the materials used and their transparency. Opaque panels can have an efficiency comparable to traditional solar panels made of the same material.
Transparent or semi-transparent panels are less efficient, because by definition a certain amount of solar energy passes through them right through without being absorbed. Hadizadeh said his company’s semi-transparent panels are about 50 to 75 percent efficient compared to regular solar panels.
However, since BIPV panels are placed where they best perform their function of cladding, windows, etc., they are generally not optimized for sun exposure like traditional panels, and therefore can generate less of energy.
Hadizadeh hopes that as architects and developers learn about BIPV and understand its potential, they will begin to design buildings “in a way that maximizes the power of the sun”.
Why aren’t more buildings installed?
Yves Poissont, research director and senior specialist in solar voltaic technologies at Natural Resources Canada, estimates that, taken together, all of the country’s BIPVs currently have less than one megawatt of electrical power, which is less than one percent of the distributed photovoltaic market. .
BIPV presents a number of challenges typical of an emerging technology:
Lack of availability. Until recently, most installations relied on products imported mainly from Onyx Solar in Spain, and they had to be customized rather than mass-produced.
However, Canadian companies like PV Technical Services and Mitrex are starting to offer access to solar shingles and siding, respectively, which are locally developed and manufactured.
Zhou said PV Technical Services already has several Canadian facilities. Mitrex plans to open a new plant in Toronto in July to ramp up coating manufacturing for its first customers, which are expected to be installed by fall. Kuby Energy, which currently sells Tesla Powerwalls in Canada, plans to sell Tesla’s solar roof when it becomes available in Canada, which is expected later this year.
Technical and regulatory challenges. BIPV products are regulated as both building materials and electrical materials, so they have to meet two sets of requirements. Hadizadeh said it requires a lot of testing and working with the government to draft regulations for a new product.
Athienite encourages adoption of these technologies, building codes need to be changed, and governments need to provide the right incentives.
Meanwhile, most tradespeople don’t know him, and Athienitis said there needs to be more education.
Cost. Right now, it’s quite expensive initially, although the electricity produced over its lifetime should eventually make up for that, Yereniuk said. Hadizedah said her goal over the next few years is to reduce the cost of Mitrex’s products to the point that they can be offered at no upfront cost to customers – instead, they would pay for the electricity produced during the service life of the panels (similar to the path geothermal projects are often financed in condos).
“It’s definitely going to take off as more and more people realize it’s a viable technology,” Yereniuk said. “The industry is changing very rapidly and technology is developing and advancing rapidly, and costs are falling rapidly.”