The Past and Future of Energy: Here Comes the Sun

Jackie Forrest is the Executive Director of the ARC Energy Research Institute and co-hosts the ARC Energy Ideas podcast, a weekly show that explains the latest trends and news in Canadian energy and beyond.

Everyone loves a sunny day! Whether hiking, playing, or spending a day at the beach, the sun’s warmth always makes us smile. That’s also because the sun is the largest energy source 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 burning 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 hydropower; it makes up 60 per cent of all generation capacity in the country. Learn more about hydroelectric power generation at letstalkscience.ca/educational-resources/backgrounders/generatingelectricity-solar-cells

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 sailboats and windmills. Now, large turbines are converting the wind’s energy into electricity. The biggest ones are so tall that they reach halfway 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 five 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 we know that the sun will continue to play a starring role.

With more discussions around Earth Day, April 22, Let’s Talk Science has put together a guide to earth-related resources and events to support you in discussing this important topic with your kids at home or in the classroom.