Renewable Energy: Definition, Types, Pros & Cons

What is Renewable Energy?

Renewable energy is useful energy that is collected from renewable resources, which are naturally replenished on a human timescale, including carbon-neutral sources like sunlight, wind, rain, tides, waves, and geothermal heat. The term often also encompasses biomass as well, whose carbon neutral status is under debate.

Renewable energy often referred to as clean energy, comes from natural sources or processes that are constantly replenished. For example, sunlight or wind keeps shining and blowing, even if their availability depends on time and weather.

While renewable energy is often viewed as a new technology, harnessing nature’s energy has long been used for heating, transportation, lighting, and more. The wind has propelled boats to sail the seas and windmills to grind grain.

The sun provided warmth during the day and helped kindle fires to last into the evening.  However, over the past 500 years, people have increasingly turned to cheaper, dirtier energy sources like coal and fracked gas.

Now that we have increasingly innovative and cheaper ways to collect and store wind and solar energy, renewable energy is becoming a more important source of energy, accounting for more than an eighth of the US generation.

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The expansion of renewable energies is also happening on a large and small scale, from solar panels on the roof of houses that can sell power back to the grid to giant offshore wind farms. Even some entire rural communities rely on renewable energy for heating and lighting.

As the use of renewable energies continues to increase, one of the main goals will be to modernize the American power grid, to integrate it smarter, safer and better regionally.

Definition of Renewable Energy

Renewable energy is the energy that is collected from renewable resources, which are naturally replaced over a human timeframe. Such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable energy often provides energy in four important areas. Like power generation, air, and water heating/cooling, transportation, and rural (off-grid) energy services.

Types of Renewable Energy

The most popular renewable energy sources examples are:

  • Solar energy
  • Wind energy
  • Hydro energy
  • Tidal energy
  • Geothermal energy
  • Biomass energy
Renewable Energy Source
Renewable Energy Source

1. Solar Energy

Humans have used solar energy for thousands of years to grow crops, stay warm, and dry food. According to the National Renewable Energy Laboratory, “more energy falls from the sun to the earth in one hour than is consumed by everyone in the world in a year.” Today we use the sun’s rays in a variety of ways to heat homes and businesses, to warm water, or power devices.

Solar or photovoltaic cells (PV) are made of silicon or other materials that convert sunlight directly into electricity. Distributed solar systems generate electricity locally for homes and businesses, either through rooftop panels or community projects that power entire neighborhoods.

Solar farms can generate electricity for thousands of homes and use mirrors to concentrate sunlight on several hectares of solar cells. Floating solar farms or “floatovoltaics” can be an effective use of sewage systems and bodies of water that are not ecologically sensitive.

Solar provides just over 1 percent of US electricity generation. Almost a third of all new generation capacities came from solar energy in 2017, second only to natural gas.

Solar energy systems don’t produce air pollutants or greenhouse gases, and as long as they are responsibly sited, most solar panels have few environmental impacts beyond the manufacturing process.

Check out our article: What is Solar Energy?

2. Wind Energy

We’re far from old-fashioned windmills. Today, turbines as tall as skyscrapers with turbines almost as wide in diameter are on the alert all over the world. Wind energy turns the blades of a turbine that feeds an electric generator and generates electricity.

Wind, which makes up just over 6 percent of US generation, has become the cheapest source of energy in many parts of the country. The most important wind power states include California, Texas, Oklahoma, Kansas, and Iowa. However, turbines can be placed anywhere with high wind speeds such as on hills and open plains or even offshore in open water.

Check out our article: What is Wind Energy?

3. Geothermal energy

If you’ve ever relaxed in a hot spring, you’ve made use of geothermal energy. The Earth’s core is about as hot as the sun’s surface due to the slow decay of radioactive particles in rocks in the center of the planet. Drilling deep wells bring very hot groundwater to the surface as a hydrothermal resource, which is then pumped through a turbine to generate electricity.

Geothermal systems typically have low emissions as they pump the steam and water they consume back into the reservoir. There are ways to create geothermal facilities that do not have underground reservoirs, but there are concerns that they could increase the risk of earthquakes in areas that are already considered geological hotspots.

Check out our article: What is Geothermal energy?

4. Tidal Energy

Tidal energy is a type of energy that collects from the waves or the tides that are calm and more or less predictable. The 3 types of methods used to transform tidal energy into electricity are tidal stream generator, tidal barrage, and dynamic tidal power. Some of these methods use in dams and hydroelectric stations.

5. Hydroelectric Power

Hydropower is the largest renewable source of electricity for electricity in the United States, although wind power is expected to take the lead soon. Hydropower is based on water that usually moves quickly in a large river or drops rapidly from a high point, and converts the power of that water into electricity by rotating the turbine blades of a generator.

Nationally and internationally, large hydropower plants or mega-dams are often viewed as non-renewable energy. Mega dams direct and reduce natural rivers and restrict access for animal and human populations that rely on rivers.

Small hydropower plants (an installed capacity of fewer than 40 megawatts) that are carefully managed cause less environmental damage because they divert only a fraction of the flow.

6. Biomass Energy

Biomass is an organic element that comes from plants and animals and includes crops, waste wood, and trees. When biomass burns, chemical energy release as heat and can produce electricity with a steam turbine.

Biomass is described as a clean, renewable fuel and greener alternative to coal and other fossil fuels to produce electricity. However, recent science suggests that many forms of biomass particularly from forests produce higher carbon emissions than fossil fuels.

Biodiversity also has negative consequences. Nevertheless, some forms of biomass energy can serve as a low-carbon alternative under the right conditions.

Check out our article: What is Biomass Energy?

Renewable Energy in the Home

1. Solar Power

On a smaller scale, we can use the sun’s rays to power the whole house with electricity – be it through PV cell panels or passive solar home design. Passive solar houses are designed to be welcomed in the sun through south-facing windows and to receive heat through concrete, brick, tile, and other heat-retaining materials.

Some solar-powered homes generate more than enough electricity that the homeowner can return excess electricity to the grid. Batteries are also an economically attractive way of storing excess solar energy so that it can be used at night. Scientists are working hard on new advances that combine form and function, such as solar skylights and roof shingles.

Check out our article: Home Solar Electric System

2. Geothermal Heat Pumps

Geothermal technology is a new version of a recognizable process. The coils on the back of your fridge are a mini heat pump that extracts heat from the interior to keep food fresh and cool. In a house, geothermal or geo-exchange pumps use the constant temperature of the earth (a few feet below the surface) to cool homes in summer and warm houses and even heat water in winter.

Geothermal systems can be expensive to install at first but usually pays for themselves within 10 years. They are also quieter, have fewer maintenance problems, and last longer than conventional air conditioning systems.

3. Small Wind Systems

A backyard wind farm? Boats, ranchers, and even cell phone companies regularly use small wind turbines. Dealers are now also helping homeowners set up, install, and maintain wind turbines, although some DIY enthusiasts install turbines themselves.

Depending on your electricity needs, wind speeds, and zone rules in your region, a wind turbine can reduce your dependence on the electricity grid.

Check out our article: Home Wind Turbine

Pros and Cons of Renewable energy

Advantages of renewable energy / Benefits of Renewable Energy

Using renewable energy over fossil fuels has a number of advantages. Here are some of the top benefits of going green:

1. Renewable energy won’t run out

Renewable energy technologies use resources directly from the environment to generate electricity. These energy sources include sunshine, wind, tides, and biomass to name a few of the most popular options. Renewable resources are not running out, which cannot be said for many types of fossil fuels. As we use fossil fuel resources, they are becoming increasingly difficult to obtain, which is likely to increase both the cost and the environmental impact of extraction.

2. Maintenance requirements are lower

In most cases, renewable energy technologies require less overall maintenance than generators that use traditional fuel sources. This is because generation technology like solar panels and wind turbines have either few or no moving parts and do not rely on combustible, combustible fuel sources to operate. Fewer maintenance requirements mean more time and cost savings.

3. Renewables save money

By using renewable energies, you can save money in the long term. You not only save maintenance costs, but also operating costs. If you’re using technology that generates electricity from the sun, wind, steam, or natural processes, you don’t have to pay to refuel.

The amount of money you save from renewable energy can depend on a number of factors, including the technology itself. In most cases, switching to renewable energy means savings of between hundreds and thousands of dollars.

4. Renewable energy has numerous health and environmental benefits

  • Generating energy that produces no greenhouse gas emissions from fossil fuels and reduces some types of air pollution
  • Diversifying energy supply and reducing dependence on imported fuels
  • Creating economic development and jobs in manufacturing, installation, and more

The use of fossil fuels not only emits greenhouse gases, but also other harmful pollutants that lead to respiratory and heart health problems. With renewable energies, you are helping to reduce the spread of these pollutants and contribute to an overall healthier atmosphere.

5. Renewables lower reliance on foreign energy sources

Renewable energy technologies allow you to produce energy locally. The more renewable energy you use for your electricity needs, the less you rely on imported energy and the more you contribute to the overall US energy independence.

Disadvantages of renewable energy

Renewable energy has many benefits, but it’s not always sunny when it comes to renewable energy. Here are some disadvantages to using renewables over traditional fuel sources.

1. Higher upfront cost

While you can save money by using renewable energy, the technologies are usually more expensive upfront than traditional energy producers. To counter this, financial incentives such as tax credits and discounts are often available to help lower your initial renewable technology costs.

2. Intermittency

Although renewable energy sources are available worldwide, many of these resources are not available 24/7 all year round. Some days may be windier than others, the sun does not shine at night, and droughts can occur for some time. There can be unpredictable weather events that disrupt these technologies. Fossil fuels are non-intermittent and can be turned on or off at any time.

3. Storage capabilities

Due to the interruption of some renewable energy sources, there is a high demand for energy storage. Although storage technologies are available today, they can be expensive, especially for large renewable energy systems. It’s worth noting that energy storage capacity grows as technology advances, and batteries become more affordable over time.

4. Geographic limitations

The United States has diverse geography with different climates, topographies, vegetation, and much more. This creates a nice melting pot of landscapes, but it also means that there are some regions that are better suited to renewable technologies than others.

For example, a large open space farm can be a great place for a residential wind turbine or solar system, while a townhouse in a city shaded by taller buildings cannot take advantage of either technology on their property. If your property is not eligible for personal renewable energy technology, there are other options.

FAQs.

What is Renewable Energy?

Renewable energy is useful energy that is collected from renewable resources, which are naturally replenished on a human timescale, including carbon-neutral sources like sunlight, wind, rain, tides, waves, and geothermal heat. The term often also encompasses biomass as well, whose carbon neutral status is under debate.

What are the types of Renewable Energy?

Following are the types of renewable energy:
1. Solar energy
2. Wind energy
3. Hydro energy
4. Tidal energy
5. Geothermal energy
6. Biomass Energy

What are the advantages of renewable energy?

Advantages of renewable energy:
1. Renewable energy won’t run out.
2. Maintenance requirements are lower.
3. Renewables save money.
4. Renewable energy has numerous health and environmental benefits.
5. Renewables lower reliance on foreign energy sources.

What are the disadvantages of Renewable energy?

Disadvantages of Renewable Energy:
1. The Electricity Generation Capacity is Still Not Large Enough.
2. Renewable Energy Can be Unreliable.
3. Low-efficiency Levels.
4. Requires a Huge Upfront Capital Outlay.
5. Takes a Lot of Space to Install.
6. Expensive Storage Costs.
7. Not Always a Commercially-viable Option.
8. It Still Generates Pollution.

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Reference

Renewable energy sources: Solar Schools