Canada's Energy Mix

Solar

On a sunny day, you can feel the warmth of the sun’s rays on your skin. Also, plants rely on sunlight to photosynthesize and make food. How do we use that same energy from the sun to produce electricity?

Eric Sehr, Sun Power, https://www.flickr.com/photos/ericvery/21778868353/, (CC BY-NC-ND 2.0)

What is solar energy and how is it used to produce electricity?

Solar energy comes from the sun. The amount of available solar energy varies depending on the season, weather and location of the technology used to harness the sunlight.

The sun’s energy can be harnessed in several ways, including solar photovoltaic cells, active solar energy, passive solar energy, and concentrating solar power systems. Solar technologies use the sun’s energy to heat homes and water and generate electricity

The most common method of converting solar energy into electricity is through photovoltaic (PV) cells, which convert sunlight into electricity that can be used, stored or added to the grid. PV cells have been installed at both the residential and commercial scale, and some solar farms cover many acres to produce electricity for thousands of homes.

Photovoltaic cells are made of thin layers of semiconductor material, such as crystalline silicon, which are specially treated/coated so that when sunlight strikes the cell, it will cause electrons to flow through it, creating an electric current. A solar panel is made up of many cells.

Active solar thermal systems capture sunlight on a collector, such as a metal plate or mirror. As collectors heat up, they transfer the energy to air or water, heating spaces and water in homes. A similar method is a concentrated solar power system, which also captures the sun’s energy using a mirror. However, in this case, the heat is used to boil liquid to create steam and produce electricity using a generator.

Passive solar heating involves using parts of a building, such as walls, windows or roofs, to absorb the sun’s energy and keep heat from escaping. For instance, high-efficiency windows are used in combination with insulation and airtight construction to keep heat inside a building.

Canada’s use of solar energy has increased in recent years, although it remains relatively small in terms of commercial use. In Canada, solar energy is mostly used to provide heat and electricity to individual homes, farms and business that are far away from the primary power grid.

Rob Campbell, Installing solar panels in Oakville Ontario, https://www.flickr.com/photos/roberrific/19362532395/, (CC BY-NC 2.0)

How does the electricity travel to where it needs to go?

Electricity produced from solar energy is transported through power lines. There are three stages in the electricity system—generation, transmission, and distribution. Generation is about producing electricity, transmission is about moving it, and distribution is about delivering it to individual customers.

Transmission lines carry electricity from generating stations to end users or consumers. When electricity is running through these lines, some electricity is lost due to resistance and dissipates as heat. To reduce the amount of electricity lost in transit, these transmission lines carry high voltage electricity.

Power generators produce low voltage electricity and in order for this electricity to be transported to where it needs to go, the voltage has to be increased. A “step up” transformer is used to convert it to a higher voltage that the transmission lines can carry. Once the electricity reaches its destination, a substation “step down” transformer converts it back to a lower voltage so that it can be used by consumers.

The last part of the electricity grid is the distribution network, which is essentially the network of wires that takes the electricity from the transformers and carries it to the end-users. Electric utilities are private companies or government organizations that handle the production, transmission and distribution of electricity. Managing the electricity grid is a complicated process and an important responsibility.

Canada is connected to the United States through an international network called the North American Power Grid. Along the U.S. border there are more than 35 transmission connections, which allow for a flexible and mutually beneficial trade in electricity between Canada and its neighbour.

What is the electricity used for?

Electricity is used in our homes and businesses for things like lighting, heating and cooling, and powering appliances and electronic devices. We live in a world dependent on electricity. From the refrigerator in your kitchen and to the computer that you’re using to access this website, electricity is the thing that makes possible most of our modern-day conveniences.

Thomas Kohler, Solar Cell, https://www.flickr.com/photos/mecklenburg/6037863041/, (CC BY 2.0)

How does solar energy impact the environment?

Solar energy is a renewable resource and its production does not directly contribute to climate change, but the manufacturing of solar panels does have an impact on the environment. While the operation of solar panels does not produce any emissions, there are environmental consequences when solar equipment is no longer in use. Photovoltaic systems often use lead-acid batteries, and although these batteries are becoming more recyclable and have longer life spans, they have the potential to contaminate groundwater at landfills. Some of the materials used for solar panels, such as cadmium and lead, are toxic. These minerals, as well as other compounds, are difficult or expensive to recycle and are considered hazardous waste, which means that they can’t simply be dumped at a regular landfill because the toxic materials could get into the soil. However, methods for recycling solar panels do exist and, as the need for it grows, countries will have to create and enforce standards for proper recycling.

Land being used for solar farms can’t be used for anything else, such as farming. In addition, animal habitats can be affected or fragmented, and some species (e.g., birds) can be harmed by the high concentration of heat over solar farms. The best way to reduce impact on wildlife is with careful site selection and to make use of existing land that has already been previously developed, such as former landfills or on top of buildings.

Where do we find solar farms in Canada?

More than 98 per cent of Canada’s solar power generation capacity is located in southern Ontario. Solar power generation depends on the availability of sunlight, so it is very seasonal and is affected by climate and latitude. In general, solar panels generate less electricity in the fall and winter, particularly in northern Ontario, where days are shorter in the winter. Quebec and the Prairies also produce some solar energy. Although small solar panel installations for homes and businesses are done all across the country, the majority of small-scale solar energy production happens in southern Canada. 

Jon Callas, Full Set of Panels, https://www.flickr.com/photos/joncallas/5358495568/, (CC BY 2.0)

Did you know?

People who produce solar energy can connect their systems to the power grid or go off grid, meaning the only source of energy will come from solar power and any other alternative energy systems in place. By using solar energy, residents save the cost of transporting electricity across long distances. As well, photovoltaic systems can include batteries that allow people to store electricity, particularly when there is a lot of sunlight. People who have abundant electricity from solar power sources have the option of supplying their excess electricity to the power grid.

In some forms, solar energy doesn’t require any transportation. Many devices, such as hand-held and desk calculators, use photovoltaic cells and need only a small amount of light to function instantly where they are.