Renewable vs. Non-renewable Energy
Many of our day to day activities, from driving a car to reading the news, depend on some kind of energy. However, some of our energy sources have harmful side effects, and so we must be mindful of where our energy comes from. An important distinction in the classification of energy sources is whether or not they are renewable. “Non-renewable” refers to a source that has a finite store and will run out (i.e. once used, they cannot be ‘renewed’). Fossil fuels, coal, and natural gas are all non-renewable sources because they are combusted, or burned, to produce energy, a non-reversible process that breaks them down into CO2 and water (1). On the other hand, renewable energies are sources of power that replenish themselves, at a rate at least equal to the rate it is consumed (2). Renewable energy sources include wind, solar, and geothermal energy, among others (1). Many renewable sources are also ‘clean’ technologies, and are promising in their ability to make energy production more eco-friendly (2).
What is ‘Clean’ Energy?
Clean technologies are those with little to no carbon footprint. Unlike burning fossil fuels, these sources are associated with little-to-no release of greenhouse gases, and thus do not significantly contribute to emissions (3). The price of these technologies has rapidly declined in recent years, allowing them to be competitive with industries such as oil and gas. Such competitiveness is an important feature that gives them promise to break the long-standing correlation between economic success and CO2 emissions (4,5).
Many clean technologies involve harvesting energy from naturally occurring processes, like the wind or tides, and as such there are many different types. Let’s have a closer look at some of the major sources of clean energy:
Wind: The primary source of wind energy is the wind turbine. The blades of a wind turbine act similarly to an airplane wing – as wind passes over the blade, it creates ‘lift’, which causes the turbine to spin. An electricity generator within the turbine converts the spinning into electricity. In Canada, our wind turbines generated over 12,000 megawatts of power in 2018, or around 6% of our country’s energy demand (6).
Solar: The most popular form of solar energy is known as a ‘photovoltaic panels’ – many would recognize these as the familiar solar panel. The panels harness energy from sunlight to generate electricity (7). Prices of solar photovoltaic energy have fallen (8). Recently, in the provinces of Prince Edward Island, Nova Scotia, and Ontario, solar energy has become more affordable than commercial energy (8). A less widespread form of solar energy is ‘thermal’ - in which heat from sunlight is converted to electrical energy (7).
Hydroelectricity: The prefix ‘hydro’ means water, and so ‘hydroelectricity’ refers to the generation of electrical energy from flowing water, including rivers and waterfalls. Here, again, a turbine with blades is spun as water passes by, and the motion of the blades is converted to electricity (9). Canada is currently the 3rd largest producer of hydropower in the world, and has the potential to increase its production (9). However, hydroelectric turbines have been shown to impact biodiversity; for example, a recent study showed that, in Nova Scotia, a river turbine has significantly decreased fish populations – and, as such, installation projects should proceed carefully (10).
Geothermal: This energy source is generated as heat from within our planet. Steam, formed from water heated by rocks deep below the earth’s surface, is collected by pipes and used to spin a turbine, which generates electricity; the water collected from condensing steam is returned underground, thereby ensuring no water is wasted (2).
Renewable Energy in Canada
As explained above, many clean energy initiatives are underway in Canada. Yet, although governments on both the provincial and federal levels have increased investments in renewable energy since 2010, a 2017 report placed Canada only 36th of 127 countries when ranked on “ability to deliver secure, affordable, sustainable energy” (11). Clearly, there is still work to be done.
The situation is improving because hydroelectricity and other renewable energy sources currently produce about 17% of the primary energy supply in Canada; however, with the decline of costs associated with renewable energy sources such as solar, that number is set to increase (5,8). Furthermore, the Pan-Canadian Framework on Clean Growth and Climate Change shows that between 2010 and 2015, the costs for new solar panel installations declined by two-thirds while, in the same time period, the cost of onshore wind decreased by about 30% (12). Sources of renewable green energy are plentiful in Canada and around the world, with a constant development of new technologies that will increase efficiency and decrease the cost of these sources (2,12,13).
Of all renewable energy sources, moving water is the most important in Canada as hydroelectricity provides about 60% of Canada’s electricity generation (7). In fact, Canada is the second largest producer of hydroelectricity in the world (2). Wind is the second most important renewable energy source in Canada, accounting for 3.5% of electricity generation in Canada and growing. Along with solar photovoltaics, wind energy is one of the fastest growing sources of electricity in Canada (2) - these are expected to lead a global expansion in renewable energy capacity of about 50% in the next 5 years (13).