Renewable energy is clean energy that comes from a source that is virtually not exhausted when used—it constantly replenishes but is flow-limited.
As of 2020, just under 12% of total U.S. energy consumption comes from renewable energy, most of which is used for electricity (“U.S. energy facts explained”, U.S Energy Information Administration, updated May 14, 2021).
Globally, only 3% of energy supply comes from renewable sources while 80% of primary energy comes from fossil fuels (CNBC on Morgan Stanley Analysis).
Switching from fossil fuel to renewable energy that is cleaner is perceived as the ultimate best solution to the energy problem. However, it has been argued by many that realistically this may not be achieved immediately without majorly disrupting the energy industry.
The ecological economist at the University of Lausanne, Julia Steinberger, spoke to CNBC about a paper he co-authored on common messaging against climate action (“It is entirely doable, and it is doable fast: Experts on how to navigate the energy transition”, Sam Meredith and Lucy Handley, CNBC, updated November 22, 2021).
The four perceptions that cause climate action delay are:
- The disruption that change will bring is not necessary
- Changing how we do things will be difficult
- Wait and see what actions other people are taking first
- Mitigating climate change is not possible
Steinberger stressed that governments will require a big budget to implement transition to decarbonisation. However, he continued to say this should be considered as an investment into the livable future.
Steve Varley, a global vice chair for sustainability at EY, a management consultancy firm, echoed Steinberger and pointed that energy prices will go up during the transition period but in the long run this will lead to cheaper energy. Varley also spoke of the importance of ensuring a reliable energy storing system during transitioning to renewable energy so we don’t see energy shortages. Developing countries will be hit harder than developed countries because of the “green power gap”.
Some researchers have argued that the costs of renewable energy are reducing therefore energy generation in this way is rising fast and could potentially replace fossil fuels sooner than most think.
Carbon Tracker, a nonprofit organization in London conducted research on solar and wind energy. They released a report stating that land that is required to generate solar energy, for example, is only 450,000 km2. That's 0.3% of the total land we have in the world (149 million km2) and far less than the total land required to generate fossil fuels.
Carbon Tracker specifically said renewable energy could push out fossil fuels by 2035 because of the reducing costs of solar and wind energy. Also, because solar and wind energy have the potential of meeting global demands of electricity more than 100 times that of fossil fuels (“The Sky’s the Limit: Solar and wind energy potential is 100 times as much as global energy demand”, Carbon Tracker, updated April 23, 2021).
The CEO of Center for International Environmental Law, Carroll Muffett, stressed how solar and wind are the cheapest source of new energy for many people around the world, and cheaper than fossil fuels. He also mentioned that in addition to being cheaper, solar energy is scalable and reaches remote areas in smaller operations without waiting for grids (“It is entirely doable, and it is doable fast: Experts on how to navigate the energy transition”, Sam Meredith and Lucy Handley, CNBC, updated November, 22 2022).
Examples of renewable energy are (“Renewable energy explained”, U.S Energy Information Administration, updated May 20, 2021):
1| Solar
Solar is technology that collects energy from the sun to be used for electricity and heat. The appealing advantage of solar energy is that it does not produce carbon dioxide and other air pollutants. Therefore it causes very minimal environmental impact.
However, the downside of solar energy is that the amount of sunlight reaching the surface of the earth is not constant and not enough. A large surface area is needed to produce a high amount of energy.
2| Biomass
Biomass is renewable energy that comes from animals and plants. The organic matter can be converted to fuel and in many countries biomass is used for heating and cooking.
Photosynthesis is the conduit for the production of biomass in plants. Carbon dioxide is consumed by plants and oxygen and water vapor are released into the atmosphere.
Even though direct burning (direct combustion) of biomass produces heat, biomass can also be converted to renewable fuels both liquid and gas) through different processes:
- Wood and wood processing waste
- Agricultural crops and farm waste materials
- Using biogenic materials (plant or animal products) in municipal solid waste (garbage)
- Treating landfill gas and biogas to remove CO2 and other gases such as hydrogen sulfide to create renewable natural gas or biomethane
- Using feedstocks (such as food grains and crops with high starch and sugar content) to create a renewable biofuel called Ethanol
- Through transesterification—converting used cooking oils, raw vegetable oils, animal fats, and other oils into biomass-based diesel fuels which can be used in diesel engines and as heating fuels
3| Hydropower
Using the force of moving water to produce energy is called hydropower. The greater the water flow and the higher the fall, the more the electricity produced at a hydroelectric power plant. A hydroelectric power plant is usually located near a water source.
To be successful in creating energy from hydropower, three steps of water cycle have to be implemented:
- The surface of a body of water such as a river is heated by solar energy and water evaporates.
- The water vapor then condenses into clouds and precipitation occurs in the form of snow and rain.
- Precipitation is collected in water bodies, i.e rivers and lakes, where the first stage the water cycle begins again (water evaporating).
At a hydropower plant, the flowing water from a river, or other water source such as a storage reservoir or dam, enters a pipe and causes blades of a turbine to spin. The drive shaft that's connected to the turbine blades turns an electric generator that will produce electricity (“Wind explained”, U.S Energy Information Administration, updated March 17, 2021).
4| Geothermal Energy
There is heat deep inside the earth that is naturally and continuously produced. This renewable energy can be used for heating buildings and for electricity. Basically, geothermal energy is produced when radioactive particles in the earth's core slowly decay. According to scientists, the earth's inner core has temperatures of about 10,800 degrees Fahrenheit (°F), just like the surface of the sun (“Geothermal explained”, U.S Energy Information Administration, updated November 19, 2020).
5| Energy from Wind
Moving air produces renewable energy mainly for electricity. The daily wind cycle is responsible for wind energy. During the day, air above land heats faster than air above the water. When the warm air above the land expands and rises, the heavier cooler air rushes in to take its place, in so doing creating wind. During the night, this process is reversed because air above land cools faster than air above water.
Water-pumping windmills are mainly used in farms to supply water for livestock.
CONCLUSION
The transition to renewable energy is not only feasible but also important for a sustainable future. Renewable sources such as wind and solar emit little to no greenhouse gases and are increasingly cost-competitive with traditional fossil fuels.
Advancements in technology and supportive policies are accelerating the adoption of these clean energy sources, leading to significant investments worldwide.
However, there are still some challenges to using renewable energy everywhere. For example, we need better ways to store energy. Also, countries that are still developing might find it harder to switch to renewable energy because it can be expensive and they may not have the right technology yet. To fix these problems, we need strategic planning so that we can all use renewable energy in the future (Financial Times, March 2025).