Everyone loves a sunny day! Whether it’s hiking, playing or a day at the beach the sun’s warmth always gives us a smile. That’s also because the sun is the largest source of energy on earth. And besides making us happy, the sun’s rays also power about 95 per cent of everything we do.
For starters, sunshine is energy for plants. People get energy from eating plants and burn wood for heat. Humans have also learned how to process various types of food and vegetation into fuels, called biofuels, that heat our homes and even power our cars.
Water power also comes from the sun. When solar energy evaporates water, it creates clouds that cause rain to fall and rivers to flow. Humans convert the energy from flowing rivers into electricity using dams. Canada is a major producer of hydro power, it makes-up 60 per cent of all generation capacity in the country. Learn more about hydroelectric power generation.
The sun is also why the wind blows. The sun warms the earth unevenly. Some places are cool, others hot. That causes air to rush from one place to another. For many centuries, humans have captured the wind’s energy with sail boats and windmills. Now, large turbines are converting the winds energy into electricity. The biggest ones are so tall that they reach half way up Toronto’s CN Tower.
Solar panels are another way of harnessing the sun’s energy. Solar panels are about the size of the top of a picnic table, flat and rectangular but with a glass top. When the sun shines on the solar panel, they produce electricity to power things like our lights, heat our ovens and even charge our electric cars. Solar panels are a bit like Lego. They can be used in small numbers, say 10 or 30 to cover the roof of your home. Alternatively, if you have a large area, over one million panels can be wired together into a massive power plant.
It may surprise you, but the gasoline you put in your car, the natural gas that heats your home, and the coal that cooks your food on the barbeque also comes from the sun. Oil, natural gas and coal come from plant matter that was buried in the dinosaur age about 100 million years ago.
While fossil fuels dominate the energy mix today – providing 80 per cent of all our energy needs – this is set to change. The emissions created from burning coal, gas and oil are warming the climate. To stop these emissions, governments and people are starting to make changes that will reduce how much is burned.
Only a small amount of energy is from non-solar sources today, about 5 per cent. Most of this is from nuclear energy that is unleashed when atoms are split apart. Geothermal energy is another source, wells are drilled into the earth to capture the heat that radiates from the earth’s crust.
Because of climate change, a transition away from fossil fuels to emission free energy is starting. With such an enormous amount of energy coming from oil, gas and coal today, it is a big challenge to change. It is uncertain how it will all unfold and how long it will take, but one thing we know for sure is that the sun will continue to play a starring roll.
With more discussions around Earth Day, April 22, Let’s Talk Science has put together a guide to earth-related resources and events that will support you in talking about this important topic with your kids at home or in the classroom. Learn more.
This article was originally published for Let’s Talk Science and the Royal Society of Canada who have partnered to provide Globe and Mail readers with relevant coverage about issues that affect us all – from education to the impact of leading-edge scientific discoveries. To read other articles visit the “Let’s Talk Science” page at the Globe and Mail.