Renewable energy means energy from a source that will replenish within a human lifetime. This is energy we can harness as long as the sun is shining, the wind blows, and water moves. Renewable energy can reduce (and eventually drop) our dependence on fossil fuels. But the best thing about renewable energy may be that it is widely available. Almost every place on earth is capable of producing energy from a renewable source. Whereas fossil fuel energy is less accessible and must be transported across the globe.
To take advantage of the ability to choose renewable energy over fossil fuels, sign the petition urging the Government of Canada to invest further in its development.
What Are the Main Types of Renewable Energy?
We’ve rounded up the most developed technologies to have a closer look.
The sun delivers more energy to the earth’s surface in one hour than the world’s population needs for an entire year. People have used passive solar energy for a long time. We’ve been using it to dry clothes, heat homes and water, and to grow and preserve food. But we’ve only recently begun to explore technology that converts solar energy into electricity.
The most common method of collecting solar energy is with photovoltaic (PV) cells. While originally made of silicon – a component of sand – PV cells are now made from a variety of materials. These solar cells create an electrical charge when exposed to direct sunlight. It is one of the most adaptable types of renewable energy. Small systems can run the appliances in a home. Larger systems, called solar farms, produce enough energy to distribute via utility companies. While these farms’ primary aim is to produce solar energy, they have another use. Many use the land for secondary crops, such as vegetables or honey.
Wind can produce two types of renewable energy:
- Mechanical (wind moves the arms of a windmill that power a grain mill)
- Electrical (wind moves large turbines that power electrical generators). These large turbines are truly massive structures. They stand 20-stories high and are fitted with blades whose span is larger than a football field. One of these can produce enough energy in one year for 600 homes. Groupings of them, called wind farms, can generate significant amounts of energy.
Wind farms are usually located away from urban areas because of their size. This makes energy transport a challenge and an extra cost. Windfarm startups can also be financially daunting, but these obstacles haven’t stunted their growth. The U.S. and China lead the world in wind energy development. Both countries have more than doubled their wind energy infrastructure since 2011.
Water, like the sun and wind, is a valuable source of kinetic energy. Hydroelectric power comes from converting that kinetic energy into electrical energy. It is done with turbines that turn in the moving water and generate electricity. To create enough energy to power cities, the water must move at a consistently fast pace. This is a process that requires structures to capture and control the water’s movement.
Most hydropower is generated by dams, which have significant pros and cons. Their ability to produce emission-free energy is undisputed. Dams produce 16.4 per cent of the world’s total electricity. Hydropower also outpaces all other types of renewable energy. It generates 71 per cent of global electricity from all renewable sources. It may not emit the same pollutants as fossil fuels, but dams can be sources of pollution when poorly planned. A dam in Brazil created a reservoir that covered a stretch of rain forest. As the trees decomposed under water, they released large amounts of methane – a greenhouse gas.
Dams provide two-thirds of the Pacific Northwest (Oregon and Washington)’s electricity. But it has also caused a 90 per cent decrease in salmon migration.
Other cons of dams include their degradation of:
- Water quality
- Riparian habitats
- the ability of fish to migrate to spawning grounds
Locals can use the naturally hot water to heat their homes or to bathe in, while municipalities pump the water under roadways to reduce ice build-up. In a few places around the world, geothermal pockets can harness power on a larger scale. In these geothermal power plants, steam moves through turbines. This generates electricity for nearby utilities.
Iceland is renown for its creativity with geothermal resources. It sources 50 per cent of its total energy needs from geothermal power. But yet the U.S. is the world leader in megawatts of geothermal power produced. And it was in the Larderello fields in Italy where commercial geothermal power got its start. It dates back to the early 1900’s, when geothermal steam was first converted into enough electrical energy to power five light bulbs. The Larderello site grew in capacity and remained the world’s only geothermal power plant for almost 50 years. Today, 24 countries produce geothermal power at a utility scale. The world’s largest geothermal power complex is at The Geysers in northern California.
Anyone who has taken a dip in the ocean knows its power. Even the slightest swell bounces you around with ease and offers a free ride back to shore if you know how to catch it. The emerging science of tidal energy aims to harness the ocean’s strength to produce clean electricity. A few facilities already exist, with the first set at the Rance River estuary in Brittany, France. Known as a barrage, the dam-like structure controls the flow of water in and out of the estuary. It runs through turbines to produce electricity. South Korea’s Sihwa Lake plant follows similar technology. Despite their efficiency, barrages require expensive infrastructure and can damage the surrounding ecosystem.
Currently, Scotland is developing a tidal power complex off its northern shore. It utilizes a variety of free-standing tidal turbines that work much like a wind turbine. Early estimates (and record-breaking trials) show the complex could generate as much energy as a nuclear power plant. That means powering upwards of 750,000 homes – without a speck of radioactive waste. Other countries, including Australia, China, Canada, Sweden and France, are investing in the development of tidal energy technologies as well. All are hoping to crack the code of affordability so these innovations can be put to use on coastlines across the globe.
If you’ve ever cooked over a campfire or heated your house with a wood stove, you’ve used biomass. That refers to fuel materials produced through photosynthesis (so, plants and their biproducts). Unlike fossil fuels, which take millions of years to form, usable biomass can mature in as little as one summer, making it a renewable resource. Biomass can refer to wood, crops grown for ethanol or plant-based oils used as biodiesel, gases captured from landfills, or gas captured from animal waste processed in a contraption known as a digester.
While biopower sources may be renewable, they aren’t particularly clean. Using biomass for energy means burning it, and that results in CO2 emissions. It may produces less emissions than fossil fuel, but it is far from the best choice in renewable energy.
Toward a 100 per cent Renewable Future
No matter how we do it, it’s clear that a switch to renewable, clean energy sources is key to curbing climate change. Many countries are doing just that, including several that are at or near 100 per cent renewable, when it comes to electricity and heat. That list includes:
- Iceland (100 per cent)
- Paraguay (100 per cent)
- Costa Rica (99 per cent)
- Norway (98.5 per cent)
- Austria (80 per cent)
- Brazil (75 per cent)
- Denmark (69.4 per cent).
While non-renewable sources still run the globe, trends point to new types of energy. In the first four months of 2018, 98 per cent of new energy capacity installed in the U.S. fell to wind and solar sectors. As we put more research and development into renewable energy, we’ll see more cities and countries make the shift to a sustainable future.