Types of Renewable Energy
In any discussion about climate change, renewable energy usually tops the list of changes the world can implement to stave off the worst effects of rising temperatures. That’s because renewable energy sources, such as solar and wind, don’t emit carbon dioxide and other greenhouse gases that contribute to global warming.
Clean energy has far more to recommend it than just being “green.” The growing sector creates jobs, makes electric grids more resilient, expands energy access in developing countries, and helps lower energy bills. All of those factors have contributed to a renewable energy renaissance in recent years, with wind and solar setting new records for electricity generation.
For the past 150 years or so, humans have relied heavily on coal, oil, and other fossil fuels to power everything from light bulbs to cars to factories. Fossil fuels are embedded in nearly everything we do, and as a result, the greenhouse gases released from the burning of those fuels have reached historically high levels.
As greenhouse gases trap heat in the atmosphere that would otherwise escape into space, average temperatures on the surface are rising. Global warming is one symptom of climate change, the term scientists now prefer to describe the complex shifts affecting our planet’s weather and climate systems. Climate change encompasses not only rising average temperatures but also extreme weather events, shifting wildlife populations and habitats, rising seas, and a range of other impacts.
Of course, renewables—like any source of energy—have their own trade-offs and associated debates. One of them centers on the definition of renewable energy. Strictly speaking, renewable energy is just what you might think: perpetually available, or as the United States Energy Information Administration puts it, “virtually inexhaustible.” But “renewable” doesn’t necessarily mean sustainable, as opponents of corn-based ethanol or large hydropower dams often argue. It also doesn’t encompass other low- or zero-emissions resources that have their own advocates, including energy efficiency and nuclear power.
Types of Renewable Energy Sources
Solar: Solar energy, a pivotal component of India’s renewable energy landscape, is generated through the harnessing of sunlight using photovoltaic (PV) cells. These cells, typically made of semiconductor materials like silicon, convert sunlight into electricity through the photovoltaic effect. In India, with its abundant sunlight, solar power has gained significant popularity and momentum. The process involves installing solar panels on rooftops, solar farms, or solar parks, allowing the PV cells to capture sunlight and produce direct current (DC) electricity. This DC electricity is then converted into alternating current (AC) through inverters for use in homes, industries, and the grid. The Government of India has been actively promoting solar energy through initiatives such as the National Solar Mission, aiming to achieve ambitious capacity targets and make solar power a substantial part of the nation’s energy mix. As a result, India has become one of the fastest-growing solar markets globally, contributing significantly to the country’s sustainable energy goals.
Wind energy: Wind energy is generated by harnessing the kinetic energy of the wind through wind turbines. These turbines, often erected in wind farms, feature large blades that capture the wind’s force and convert it into rotational motion. The spinning motion drives a generator, producing electricity. India has witnessed substantial growth in wind energy capacity, with installations in states like Gujarat, Tamil Nadu, Maharashtra, and Karnataka. As of my last knowledge update in 2022, India was among the top wind energy producers globally, with a cumulative installed capacity exceeding 40 gigawatts (GW). The country has set ambitious targets to further expand its wind energy capacity, contributing significantly to its commitment to increasing the share of renewables in the overall energy mix.
Hydropower: For centuries, people have harnessed the energy of river currents, using dams to control water flow. Hydropower is the world’s biggest source of renewable energy by far, with China, Brazil, Canada, the U.S., and Russia being the leading hydropower producers. While hydropower is theoretically a clean energy source replenished by rain and snow, it also has several drawbacks.
Large dams can disrupt river ecosystems and surrounding communities, harming wildlife, and displacing residents. Hydropower generation is vulnerable to silt buildup, which can compromise capacity and harm equipment. Drought can also cause problems. In the western U.S., carbon dioxide emissions over a 15-year period were 100 megatons higher than they would have been with normal precipitation levels, according to a 2018 study, as utilities turned to coal and gas to replace hydropower lost to drought. Even hydropower at full capacity bears its own emissions problems, as decaying organic material in reservoirs releases methane.
Dams aren’t the only way to use water for power: Tidal and wave energy projects around the world aim to capture the ocean’s natural rhythms. Marine energy projects currently generate an estimated 500 megawatts of power—less than one percent of all renewables—but the potential is far greater. Programs like Scotland’s Saltire Prize have encouraged innovation in this area.
Nuclear energy: A powerful and controversial source, Nuclear energy, involves harnessing the energy released during nuclear reactions. In India, nuclear power plays a strategic role in the energy mix, contributing a significant portion of electricity. Nuclear reactors utilize controlled fission reactions, where the nucleus of an atom is split, releasing an immense amount of heat. This heat is then used to produce steam, driving turbines that generate electricity. While nuclear energy is lauded for its low carbon emissions and high energy density, it also raises concerns regarding safety, radioactive waste disposal, and the potential for accidents. As India continues to expand its energy portfolio, the role of nuclear energy in meeting growing demands is a subject of ongoing debate and development.
Biomass: Biomass energy includes biofuels, such as ethanol and biodiesel, wood, wood waste, biogas from landfills, and municipal solid waste. Like solar power, biomass is a flexible energy source, able to fuel vehicles, heat buildings, and produce electricity. But biomass can raise thorny issues.
Critics of corn-based ethanol, for example, say it competes with the food market for corn and supports the same harmful agricultural practices that have led to toxic algae blooms and other environmental hazards. Similarly, debates have erupted over whether it’s a good idea to ship wood pellets from U.S. forests over to Europe so that it can be burned for electricity. Meanwhile, scientists and companies are working on ways to more efficiently convert corn stover, wastewater sludge, and other biomass sources into energy, aiming to extract value from material that would otherwise go to waste.
Geothermal: Used for thousands of years in some countries for cooking and heating, geothermal energy is derived from Earth’s internal heat. On a large scale, underground reservoirs of steam and hot water can be tapped through wells that can go a two kilometers deep or more to generate electricity. On a smaller scale, some buildings have geothermal heat pumps that use temperature differences several meters below ground for heating and cooling. Unlike solar and wind energy, geothermal energy is always available, but it has side effects that need to be managed, such as the rotten-egg smell that can accompany released hydrogen sulfide.
Ways To Boost Renewable Energy
Boosting renewable energy involves a multifaceted approach aimed at increasing its adoption and efficiency. First and foremost, governments and policymakers can play a pivotal role by implementing supportive policies, incentives, and regulatory frameworks that favor renewable energy development. Investing in research and development to enhance technology and decrease costs is essential for making renewables more accessible. Additionally, fostering public awareness and education on the benefits of renewable energy can drive consumer demand. Collaboration between the public and private sectors is crucial for scaling up renewable projects and innovations. Encouraging international cooperation and sharing best practices can further accelerate the global transition to sustainable energy sources. Ultimately, a combination of policy support, technological advancements, public engagement, and international collaboration is key to boosting the widespread use of renewable energy.
