Sustainable energy
Sustainable energy, also known as renewable energy, encompasses naturally occurring energy sources that replenish quickly, including hydroelectric, solar, wind, geothermal, ocean power, and biofuels. These alternatives have gained traction in response to environmental, political, and safety issues associated with conventional energy sources like fossil fuels and nuclear power. Concerns about carbon emissions from fossil fuels contributing to climate change, the safety of nuclear waste, and geopolitical vulnerabilities tied to petroleum reliance have prompted exploration of sustainable energy technologies.
Hydroelectric power is the most prevalent form of sustainable energy, utilizing flowing water to generate electricity. Solar energy serves dual purposes, providing heating through solar water heaters and electricity via photovoltaic systems. Wind energy harnesses natural wind flow to power turbines, while geothermal power taps into underground heat sources. Emerging technologies in ocean power leverage the dynamics of tides and currents to produce electricity. However, challenges persist in widespread adoption, including high initial costs, site-specific requirements, and the intermittent nature of resources like solar and wind. Biofuels, derived from plant or algae sources, present an intriguing alternative for the transportation sector, aiming to offer a more consistent energy supply similar to that of fossil fuels.
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Sustainable energy
Sustainable energy, also sometimes called “renewable energy,” refers to sources of energy that are naturally occurring and regenerate at a rapid rate. Such sources include hydroelectric, solar, wind, geothermal, and ocean power, along with biofuels (plant- or algae-based liquid fuels).
The conventional energy sources for electric power generation, heating and cooling systems, and transportation are fossil fuels (coal, petroleum, and natural gas) and nuclear power. In the late twentieth and early twenty-first century, numerous concerns arose over the production and use of conventional energy. In response, various sustainable energy initiatives have sought to supplement or replace these energy sources.
Overview
Since the late 1950s, the production and use of conventional energy sources have generated significant environmental, political, and safety concerns. Some observers warn that fossil fuel–generated carbon emissions contribute to global climate change and that nuclear power is unsafe, with contamination around both mining sites and waste storage facilities. Others desire US energy independence, seeing reliance on foreign supplies of petroleum in particular as making the country economically and politically vulnerable. Still others raise concerns that the maximum production of fossil fuels will peak and the finite supply soon run out, a concept known as “peak theory.” Furthermore, the growing global population and industrialization of developing countries translate into rising energy demand worldwide. Sustainable energy technologies are being explored as alternative or additional sources of energy that emit no or low amounts of carbon, produce fewer environmental pollutants, enable or increase domestic energy production, and replenish quickly.
Hydroelectric power is the most widely used sustainable energy technology. It harnesses the energy from flowing water to turn turbines, generating electric current.
Solar energy is used for both heating and electricity. Solar water heaters capture solar energy and distribute the heat throughout a building, while photovoltaic (PV) arrays and concentrating solar power (CSP) devices convert solar energy into electricity.
Wind energy produces electricity by turning the blades of a turbine, much as water does in a hydropower plant. As some locations are naturally windier than others, wind turbines must be placed where the energy-generation potential is greatest, such as offshore areas and the American Great Plains.
Geothermal power taps into underground reserves of steam and hot liquids to produce electricity and distribute heat, and water is later recycled back into the reservoirs. Areas with naturally occurring hot springs, such as the western United States and Iceland, have been the first to adopt geothermal power.
Ocean power employs the movement of tides, currents, or waves; differences in surface and deep ocean temperatures; or differences in salinity (saltiness) to generate electricity.
Ongoing challenges to the widespread adoption of sustainable energy plants and devices include upfront costs, site placement, aesthetics, animal safety, and in the case of wind turbines, noise. Supply-and-demand issues are a hindrance as well. Because the availability of solar, wind, and water power fluctuate over time, these resources are often called “variable renewables.” In contrast to existing energy models, which feature constant, on-demand availability, variable renewables require flexibility in energy production, storage, and distribution, presenting both an innovation challenge and an opportunity for greater efficiencies.
Another sustainable energy alternative that aims to more nearly approximate the performance and availability of conventional fossil fuels is biofuel. Biofuels are derived from plants or algae that photosynthesize energy from the sun, and are typically made available as liquids, much like the petroleum products gasoline, kerosene, and diesel. Consequently, biofuels have greater potential to affect the transportation industry.
Bibliography
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