Renewable energy Definition and 23 Discussions

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. This type of energy source stands in contrast to fossil fuels, which are being used far more quickly than they are being replenished. Although most renewable energy is sustainable energy, some is not, for example some biomass is unsustainable.Renewable energy often provides energy in four important areas: electricity generation, air and water heating/cooling, transportation, and rural (off-grid) energy services.Based on REN21's 2017 report, renewables contributed 19.3% to humans' global energy consumption and 24.5% to their generation of electricity in 2015 and 2016, respectively. This energy consumption is divided as 8.9% coming from traditional biomass, 4.2% as heat energy (modern biomass, geothermal and solar heat), 3.9% from hydroelectricity and the remaining 2.2% is electricity from wind, solar, geothermal, and other forms of biomass. In 2017, worldwide investments in renewable energy amounted to US$279.8 billion with China accounting for 45% of the global investments, and the United States and Europe both around 15%. Globally there were an estimated 10.5 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer. Renewable energy systems are rapidly becoming more efficient and cheaper and their share of total energy consumption is increasing. As of 2019, more than two-thirds of worldwide newly installed electricity capacity was renewable. Growth in consumption of coal and oil could end by 2020 due to increased uptake of renewables and natural gas. As of 2020, in most countries, photovoltaic solar and onshore wind are the cheapest forms of building new electricity-generating plants.At the national level, at least 30 nations around the world already have renewable energy contributing more than 20 percent of their energy supply. National renewable energy markets are projected to continue to grow strongly in the coming decade and beyond.
At least two countries, Iceland and Norway, generate all their electricity using renewable energy already, and many other countries have the set a goal to reach 100% renewable energy in the future.
At least 47 nations around the world already have over 50 percent of electricity from renewable resources. Renewable energy resources exist over wide geographical areas, in contrast to fossil fuels, which are concentrated in a limited number of countries. Rapid deployment of renewable energy and energy efficiency technologies is resulting in significant energy security, climate change mitigation, and economic benefits. In international public opinion surveys there is strong support for promoting renewable sources such as solar power and wind power.While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. As most of renewable energy technologies provide electricity, renewable energy deployment is often applied in conjunction with further electrification, which has several benefits: electricity can be converted to heat, can be converted into mechanical energy with high efficiency, and is clean at the point of consumption. In addition, electrification with renewable energy is more efficient and therefore leads to significant reductions in primary energy requirements.

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  1. Raz Matazz

    I Why do electrons always move?

    Whether in vacuum inside a CRT, or in a metal, a potential difference has to be applied for free electrons to move from the negative to the positive terminal. However, the reality is that free electrons are still moving when no voltage is present at the 2 ends of a metal conductor. In this...
  2. P

    Good Software to download and familiarize myself with

    Hey Everyone, I am a junior Physics major who would like to pursue a career in Renewable Energy Engineering. I am interested in the part of the development in which I would be designing the software, machine and every other component that goes along with the actual device (whether it be for...
  3. T

    Vertical wind turbine with two concentric rotors

    Hello. For a long time, I wanted to build a wind turbine prototype that would have two concentric rotors. The design was inspired by an automotive torque converter, used with automatic transmissions. This device would have an external rotor that would be coupled to one generator and an internal...
  4. J

    Microbiological Fuel Cell: Negative Voltage

    Hello! I've been working on a few soil based MFCs and I have been monitoring my voltage and energy output for a week now. I've made the electrodes by covering stainless steel metal meshes with activated carbon using epoxy. I've gotten some funky results as attached. As you can see... the...
  5. Ahmad Esber

    B Is it possible to harvest energy from fluid buoyancy?

    So I've noticed my little sister's helium balloons floating at the ceiling. Made me wonder if someone could create a device that could harvest energy from this buoyancy. What if I tied a very long rope to a huge balloon filled with helium, and rolled the other end of the rope to a gear attached...
  6. T

    AC Mains meter circuit design for energy sources...

    What circuit design is used to ensure that the renewable energy source does not begin to absorb energy from the grid (for instance, when its terminal voltage drops below the distribution line voltage)?
  7. Waggles

    Renewable Energy Concept - Stirling Engine Composting

    So I've got this crazy idea. To put it simply, to use the heat from anaerobic composting to power hot-air engine, specifically a Stirling Engine. Based solely on my own reading, the center of a closed composting heap can reach anywhere from 120-160 degrees without killing the microorganisms...
  8. C

    Increasing the Power Output of a Turbine

    I have a hydro turbine spinning at 62.746RPM and it produces 170.195Nm of torque. It generates 1.1183kW but ideally, I would like to step it up to at least 4.5kW. Is this possible using a gearbox and if so how can it be done?
  9. Rod Alexei

    What do you guys think about Dynamic Tidal Power?

    I am a 16 year old trying to make a research paper about it for my science high school. I'd like to study how it works and whether it can be applicable to Busan, South Korea. Thank you :)
  10. R

    I Carbon in air to graphene?

    Is it feasible to turn the abundance of carbon in the atmosphere into graphene, given it is an allotrope of carbon and would it be worth the trouble?
  11. I

    Engineering Energy systems engineering + business

    so I ill be going into my first year of energy systems engineering but I would really love to develop my own business surrounding things like biofuels and wind farming , i was just wondering what prospects are their to develop a business or if there are any sort of ideas around that field.
  12. F

    Solar thermal collectors in parallel

    I am using TRYNSYS software to simulate solar thermal cooling. I need to install many solar thermal panels (evacuated tubes) in parallel. However, there is no feature to do that automatically in the software; so I can only add them manually with complex piping and stuff. So my question is: Is...
  13. SherLOCKed

    How can I interface a DFIG in a multi machine environment?

    Which will be my reference frame while modelling and control - the reference machine in the network or the network bus itself?And if so how do i relate the dfig to this reference frame?
  14. I

    Engineering Renewable energy engineering

    hello everyone, I just need some advice from others right now, so I'm going into the field of renewable energy engineering. more importantly I just wanted to know about the job prospects, where it could be in the years to come,job settings ( what would be the environment I would work in ?). and...
  15. W

    Is sound a renewable energy or non-renewable energy?

    I've been searching the web for this answer and can't seem to find it anywhere. Can anyone help me? Is sound a renewable energy or non-renewable energy?
  16. T

    Alternative energy career?

    Hello, I have been thinking about this for awhile and struggling with what I want to do so some guidance would be helpful. Right now I am studying astrophysics and I've been in love with it for the better part of a year being that I find a lot of interest in solving problems in physics and...
  17. nar5i

    Need some help with piezoelectric plates

    I am doing my wrong project from school. Its basically a science fair but only for the students in the class. I came up with the idea to use piezoelectric plates to charge a capacitor that then charges one of those portable po charge a phone. I know I'm not the first one do this, but I do want...
  18. TMECLT

    Programs What Major Is Best For My Future?

    I know that when I get out of school I want to help develop solar roadways, bike paths, and parking lots. Potentially even help with the efficiency rate of solar panels. However, I'm currently a mechanical engineering student with a concentration in energy. The only way to get a concentration in...
  19. J

    Engineering What should i do with my life? (engineering or physics)

    Hi, I'm Joel and I am pretty much finished school in Australia and have to make a decision about university in the near future. I love science (especially Physics) and mathematics at school so am certain that I will go into Science or Engineering but I am not quite sure what type. Whatever I do...
  20. P

    Flywheel design estimation

    Hi fellow scientists and engineers, I have a question regarding the design of a flywheel. I know that the actual engineering of a flywheel is very complex and in no way I should expect actual practical answers from this simple question. I'm just trying to get some estimates for a renewable...
  21. Domenico94

    Solar panels and optical parametric oscillator

    Hi everyone. On these days, by watching solar panels and similar stuff, I just thought about it, and why they take such a wide surface to produce energy, and why their output is often low, as we all know. By navigating here on the internet, I've just seen a device called OPO (Optical...
  22. R

    Why aren't turbines used in water supply systems?

    I had an idea to put a rotating mill turbine into the pipes that supply water to home tap systems. So that as the water flows through, the turbine is spun and electricity is produced. But why isn't this actually done?
  23. Moriarty

    Fusion and Renewable Energy Education Paths

    My counselors, advisers, and teachers are tired of me so I've come here for some help. I've been interested in renewable energy since I was much younger, but was wondering what kind of path one goes down to dive into becoming a part of the research involved in figuring out our problems with...