Harnessing the sun’s rays for energy is beneficial for both humans and the environment! How does solar energy work? Solar panels are composed of photovoltaic cells. The panels are composed of semi-conductors such as silicon and use light energy from the sun to generate electricity. When photons from the sun hit the silicon atoms in the cells, they transfer their energy, which frees up the electrons. An electrical imbalance is created by the silicon in the solar cell, which makes the electrons flow in the same direction (this creates an electric current)! There are numerous advantages of solar energy, as it is a free source of power, and it is a source of clean energy. Fun fact: a sloped residential roof at 45 degrees with a system size of 1 kW can produce 1141 kW/year (http://ottawasolarpower.com/osp2012/faqs.htm). For more information on solar power, visit http://www.cansia.ca/.
When wind flow is harvested by turbines, wind energy is created which can be used to generate electricity. How does wind energy work? Wind turbines convert the kinetic energy in the wind into mechanical power. The turbines power generators which supply the electric current, which is then fed into a utility grid. Wind farms create bulk electrical power, and are composed of groups of turbines. Fun fact: in 2012, “electricity generated by wind energy grew to 6,200 megawatts (mw) of installed capacity, maintaining Canada’s position as one of the world’s leading wind energy markets”(http://www.thespec.com/opinion-story/2226895-wind-energy-is-a-better-deal-for-ontario-than-new-nuclear/). Wind energy is a non-polluting, renewable resource. Wind farms do not produce greenhouse gases. For more information on wind power, visithttp://www.canwea.ca/ and http://windfacts.ca/.
Bioenergy and Anaerobic Digestion
Bioenergy is derived from natural biological sources. How does bioenergy work? Biofuels use energy from carbon fixation and are derived from biomass (plant material). Biomass can be converted to energy in three ways: thermal conversion, chemical conversion, and biochemical conversion in a solid, liquid, or gas form. Biofuels reduce dependence on foreign oil, reduce greenhouse gases, and are a form of renewable energy!
Anaerobic digestion is a form of renewable energy, and occurs when microorganisms break down biodegradable material. Waste from animal excrement and organic material is fed into an anaerobic digestion chamber, where millions of bacteria break down the waste. The resulting mixture is a fertilizer composed of methane and carbon dioxide. This process creates a biogas which can be burned to create energy. Fun fact: according to the Ontario Ministry of Agriculture and Food, “a dairy herd of 100 cows produces enough manure to generate a continuous 25 to 30 kW. Adding 25 per cent good quality off-farm source material such as grease trap waste from restaurants will triple the electrical output” (http://www.omafra.gov.on.ca/english/engineer/ge_bib/biogas.htm). For more information on bioenergy, visit http://www.canbio.ca/.