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The Future of Energy: Sustainable Energy Sources Compared
- Monica Macaes
- 5 days ago
- 4 min read
The world is facing an enormous challenge of converting to clean energy. Sustainability is the primary aim, which means current energy requirements must be met without harming the future. An efficient energy system must be able to conserve the environment, conserve resources, and be cost-effective. As fossil fuels are not replenishable and harm the environment, it becomes imperative to give weight to three major renewable energy sources: solar, wind, and hydropower.
For over a century, the global economy has relied heavily on fossil fuels: coal, oil, and natural gas. While instrumental in driving the industrial revolution, these non-renewable sources are inherently finite and carry substantial environmental and geopolitical liabilities. Their combustion releases immense quantities of greenhouse gases, primarily carbon dioxide, accelerating global climate change and its associated consequences, such as extreme weather events and rising sea levels. Furthermore, dependence on geographically concentrated fossil fuel reserves creates volatile global energy markets and subjects national economies to supply chain risks and price instability, underscoring the urgent need for locally sourced, reliable alternatives.
The engineering principle of this topic is the generation of electric power. Most electricity supplied by utilities is generated by converting mechanical power to electric power via an electromechanical generator. Faraday's Law of Electromagnetic Induction*, i.e., that a conductor moving through a magnetic field induces an electric current, governs this operation. Renewable energy engineering entails the development of systems that properly harness recurrent natural forces such as solar radiation, wind, and water flow, and convert this energy to mechanical energy for turbine-generator sets or, for solar energy, straight into electricity.
*Faraday's Law means that when you move a metal wire through a magnetic field, or move the magnetic field around the wire, you create an electrical voltage. This voltage makes a current, or flow of electrons, in the wire. |
Solar power, a widely applied renewable power source, harnesses solar radiation through photovoltaic (PV) technology. A PV cell is a semiconductor material, commonly silicon, that operates on the photovoltaic effect. Solar photons that reach the silicon P-N junction excite electrons, releasing them from the atomic bonds. Electrons are pushed by the internal electric field to produce a direct current (DC). This in-line process of converting light into electricity with no moving parts lends itself to scale up from home installations into solar farms. Learn More
Wind power is another well-known source of green energy that utilizes the air’s motion to create energy. Wind turbines operate on the principle of reverse propellers: wind turns the blades, generating mechanical energy to produce electricity. The system slowly spins blades connected to a high-speed generator, via a gearbox. When the coils and magnets in the generator move back and forth, alternating current (AC) is produced. The wind turbines are high-tech machines whose blades and orientation change to make the most of energy collection. Learn More
The third recognized source, hydropower, relies on the kinetic energy of flowing or dropping water. Hydropower, a major renewable source, leverages the kinetic energy of flowing water. Hydroelectric power plants harness dams to create a height gradient, called head, which translates gravitational potential energy into kinetic energy as water flows downhill. Such high-velocity flow passes through a penstock to drive the blades of a hydraulic turbine, i.e., a Francis or Kaplan turbine. The turbine is mechanically linked to a generator, which transforms mechanical torque into electrical power through electromagnetic induction. Learn More
Hydropower is distinguished by its potential to produce dispatchable, demand-driven electricity by manipulating water flow at zero environmental cost. For example, solar power concentrators and wind farms require a big piece of land, which can lead to potential loss of habitats and fragmentation, especially for wildlife. Wind turbines pose a hazard to flying animals, especially birds and bats.
Hydropower, despite its efficiency, can disrupt river ecosystems by blocking fish migration and altering sediment transport. To offset these impacts, policy-makers and engineers will have to collaborate on strategic siting, use existing degraded lands wherever possible, possess sophisticated monitoring systems to reduce wildlife interactions, and develop smaller, less intrusive technologies, such as run-of-river or decentralized solar installations. Briefly, solar, wind, and hydro power integration and development are the solutions to the energy future. Although these technologies do pose environmental problems, they are themselves small in comparison with the environmental risks of using fossil fuels and inducing global warming.
Ongoing improvements in photovoltaic conversion efficiency, turbine blade aerodynamics, and environmental mitigation technologies are enabling the establishment of a reliable, sustainable, and resilient energy grid to meet future societal needs.
Reference List
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Figure 2 - [online]; Available at: https://circuitglobe.com/wp-content/uploads/2015/08/faradays-law-fig-1.jpg
Figure 3 - [online]; Available at: https://alterno.net/wp-content/uploads/2024/12/sustainable-energy-1.jpg
Solar Photovoltaic Cell Basics. energy.gov/eere/solar/solar-photovoltaic-cell-basics. https://www.energy.gov/eere/solar/solar-photovoltaic-cell-basics
4.2 P-N Junction | EME 812: Utility Solar Power and Concentration. www.e-education.psu.edu/eme812/node/606. https://www.e-education.psu.edu/eme812/node/606
How Do Wind Turbines Work?. energy.gov/eere/wind/how-do-wind-turbines-work. https://www.energy.gov/eere/wind/how-do-wind-turbines-work
(2023). Through energy droughts: hydropower's ability to sustain a high output. https://arxiv.org/abs/2405.13530
Can wind turbines harm wildlife?. U.S. Geological Survey. https://www.usgs.gov/faqs/can-wind-turbines-harm-wildlife
(2022). Hydropower and the environment. U.S. Energy Information Administration. https://www.eia.gov/energyexplained/hydropower/hydropower-and-the-environment.php
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