There are four main types of renewable energy: solar power, wind power, hydroelectricity, and geothermal energy. These resources are not only eco-friendly but also produce fewer emissions when compared to non-renewable fossil fuels like coal and oil.
Fossil fuels, on the other hand, are natural resources that took hundreds of millions of years to form and cannot be replenished. They are a major contributor to climate change, and we must shift towards renewable sources of energy to protect the planet.
Solar Power
Solar power uses the sun’s energy to generate electricity. This is done with photovoltaic (PV) cells, which convert sunlight into energy that can power small electronics or homes and buildings.
These PV cells are arranged in panels to capture large fields of sunlight and generate energy. They are most commonly used in large-scale photovoltaic power stations, but they can also be installed on top of houses and other buildings.
Whether used to generate thermal or electrical energy, solar technologies deliver an inexhaustible supply of free, renewable, nonpolluting, and ‘green’ energy that could potentially satisfy all of the world’s future energy needs.
There are two main types of solar technologies: photovoltaics and concentrating solar power (CSP). Concentrating solar power is larger-scale than residential or commercial PV, using lenses or mirrors to concentrate sunlight into a narrow beam that heats a fluid to produce steam and drives a turbine that produces electricity.
Hydro Power
Hydropower is a form of renewable energy that uses water to generate electricity. It is a relatively cost-effective way to produce electricity, especially for smaller communities.
Hydropower plants are typically located on or near a water source, such as rivers, lakes, or waterfalls. The amount of electricity that a plant can produce depends on the volume of water flow and the change in elevation (also called head) from one point to another.
Several different types of hydropower facilities exist, including dams, run-of-river, and pumped storage plants. Pumped storage hydropower stores energy by pumping water uphill from a lower pool to an upper reservoir and then releasing it back to the river during periods of high demand.
In addition to generating power, hydropower can also help reduce greenhouse gas emissions. It is a clean, renewable source of energy that avoids the use of fossil fuels and limits pollution. It is one of the most widely used forms of energy on Earth.
Biomass Energy
Biomass is an organic, renewable resource that’s been used for centuries to heat homes and cook food. It’s also the main source of energy for some power stations.
Biomass energy can come from wood, plant residues and grasses, forestry waste, oil-rich algae, and the byproducts of other industries (such as waste gases, landfill gas, or animal waste).
It’s a type of carbon-neutral energy that can be converted into electricity, heating, and transport fuels. It can help reduce greenhouse gas emissions and is an effective way to meet the Paris climate agreement’s 20% renewable energy target.
Biomass can also be grown from old-growth forests, which are known to sequester more carbon than new-growth trees. However, this is only achieved when the trees are cut, replanted, and given time to grow before being burned for fuel.
Hydrogen
Hydrogen is a versatile fuel that can be produced, stored, and transported in a wide range of ways. It can be used to power homes and industries, as a fuel for cars, trucks, and ships, or to store excess renewable energy.
Today, hydrogen is produced by steam methane reforming (SMR), which uses a catalyst to react methane with high-temperature steam. This produces gray hydrogen.
Electricity is then used in a process called electrolysis to split water into hydrogen and oxygen. This is used in fuel cells or refueling equipment and is becoming increasingly popular for electric vehicles.
The cost of producing hydrogen from low-carbon electricity is declining. This makes the production of green hydrogen more affordable. But it still needs a scale-up of three orders of magnitude over the next 30 years to become competitive with traditional fossil fuels.