What is Renewable energy: Definition and 67 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. L

    Admissions DOE SULI Advice For Biology Background - Renewable Energy Development

    Hi Everyone! I am an upperclassmen undergrad of a biol background, with mainly course training in biochemistry and molecular biol, and taken chem like o-chem and a-chem, and introductory physics. I have three short term summer projects at top 5 institutions in the past and in the field of...
  2. 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...
  3. 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...
  4. H

    Engineering International Renewable Energy

    For members of this forum that live outside of the United States: have you seen a boom in Renewable Energy? Do you know of universities that specialize in Renewable Energy, are there companies on the cutting edge of this field?
  5. H

    Engineering Entry level Renewable energy engineering positions?

    I'm not out of college yet, but I'm curious if any companies are offering entry level positions renewable energy engineers right now
  6. E

    Why the fascination with intermittent renewable energy sources?

    Maybe I’m missing something, and this thread is to at least try to drill down into this to help me understand what that something might be… Basically I do not understand the almost cult like fascination with intermittent renewable energy for utility scale electricity production. My current...
  7. 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...
  8. anorlunda

    Insights When Renewable Energy Meets Power Grid Operations

    Continue reading...
  9. ORF

    What limits the amount of renewable energy sources?

    Hello, I was told every country needs a constant electricity production source (like coal or nuclear powerplants), and up to some proportion, renewable sources (photovoltaics, hydro, wind turbines, etc). So, my question is: what limits the amount of renewable sources? (the grid, storage...?)...
  10. 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...
  11. TMT

    Recycled Energy versus Renewable Energy

    To days trend topic is “Renewable Energy”. Everybody are trying to jump in this topic wagon. They are discussing either wind or solar farm is better choice for future investment. They also arguing their solution will prevent global warming. But, in my opinion (especially wind farms) will yield...
  12. 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...
  13. 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)?
  14. 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...
  15. 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?
  16. 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 :)
  17. 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?
  18. J

    I think I may have found a renewable energy source

    Hello guys so I have this idea of mine which I can't get my head around and I need someone to tell me why it won't work, so let's say you have a fully pressurised tank of air and you blow that pressurised air at a turbine connected to a generator, ovisously the generator will then start to...
  19. 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.
  20. C

    I Renewable Energy questions

    Hello everyone, I'm currently working on slabs (titles) that convert people's footsteps into electrical power via kinetic energy. Now, because I've been working with this tech over the past few months I've been thinking of new ideas for renewable energy sources.-not recreate just add to or...
  21. 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...
  22. 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?
  23. 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...
  24. 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?
  25. 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...
  26. 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...
  27. 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...
  28. 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...
  29. A

    Ideas merging nuclear science & renewable energy technology

    Hello everyone, I'm looking for a senior design project idea that incorporates nuclear science/engineering with the technology used in renewable energy engineering. My partner and I have found the idea of betavoltaics but doubt we'd have the required beta sources available in our labs. The...
  30. S

    Can renewable energy be stored?

    HI! I am wondering if electricity generated from a friction driven turbine by winding for example can actually be stored in a battery for later consumption? Best Regards
  31. B

    Renewable Energy and Robotics

    I am a sophmore in college and I am currently majoring in Material Science Engineering and Mechanical Engineering. I want to some day hopefully work with either Robotics and/or Renewable Energy. I want to get a good combination of Mechanical, Chemistry, Electronics, computers, and basic...
  32. 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...
  33. 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...
  34. 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?
  35. 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...
  36. A

    MS in Renewable Energy

    HI. I am in final year of Civil Engineering and my area of interest totally in new innovations. the things which are impossible, m try it to prove it is possible! m interest to do something in wind turbine. So could i do MS in renewable energy (Wind Turbine)?? or any other course? please suggest me.
  37. A

    Osmotic power - a new form of renewable energy

    Osmotic power is a form of renewable energy under development which exploits the salinity gradient between fresh river water and salt sea water. The phenomenon is based in osmosis principle and called Pressure Retarded Osmosis (PRO). The two fluids are separated by a semi-permeable membrane...
  38. T

    Engineering Renewable Energy Careers (Specifically Engineering)

    I am going into my second year in electrical engineering at a large state school. In my first year I was able to earn a scholarship within the college of engineering and also land an internship at one of the world's largest and most recognizable companies. This summer I'm in the oil and gas...
  39. T

    B.S. in EE trying to transition into a renewable energy career

    I'm currently on a career path I got into through an applied physics masters, but there isn't much of future in my particular field so I'm trying to switch. Additionally, I'm very concerned about climate change and I have a B.S in Electrical Engineering (with a minor in physics), so I'm...
  40. R

    Project help 'Power quality in renewable energy systems'

    I am currently undertaking a HND in Electrical Engineering and for my graded unit project I have chosen 'Power quality in renewable energy systems'. I was hoping someone could recommend a good book to help. Thanks
  41. Astronuc

    News Reducing subsidies for renewable energy

    Germany eyes swift cuts in renewable energy subsidies http://news.yahoo.com/germany-eyes-swift-cuts-renewable-energy-subsidies-164549194.html [Broken] See also - https://www.physicsforums.com/showthread.php?t=607814 In the US, some wind producers use 'negative' pricing to push their power...
  42. J

    Evaluate Renewable Energy Concept

    Hello, . . I have this concept sketch, of a new configuration from what I have been seeing in,. "wave energy", (in this case tide flow force energy), . . I believe that generally speaking, as a concept, there seems to be advantages. Although this is just the water wheel without turbine in...
  43. H

    Guidance on choice of a thesis topic in Renewable Energy for an undergraduate

    I'm presently pursuing my undergraduate in Mechanical Engineering, and I need help in choosing a thesis topic in Renewable Energy(as that is what I want to pursue my future in). My university is not equipped with state of the art labs, though they manage to meet the requirements of having the...
  44. C

    Programs Renewable Energy Phd programs in US

    Hi everyone, What do you know about renewable energy phd programs in US? I skimmed through the internet for it, however I couldn't find many. Renewable energies are very crucial and its researches are very promising. Why there are only few universities with energy institutes or graduate...
  45. L

    Idea for a senior project related to renewable energy

    dear members, i would like to thank the owners of this forum for giving us students the opportunity to share our ideas and thoughts about topics related to electronics. i would like to help me pick up few thoughts or ideas for a senior project related to renewable energy such as solar or...
  46. Andre

    News Renewable energy EU under pressure.

    The Frankfurter Algemeiner (something like the Times, but then in another country) has a rather important article here.. It seems that an internal EU strategy paper has leaked, in which it is proposed to stop green energy support as it becomes prohibitive expensive. One may wonder if this had...
  47. E

    Exploring Renewable Energy: My College Search Journey

    I am a Junior in high school and am just starting the college search. I have always wanted to so something with space, and be an astronaut if I could, but, as astronauts take up such a small percentage of any group of people, I have begun to look for other things. Something that has caught my...
  48. J

    Renewable Energy Prototype

    i am having problem on making my thesis about renewable energy. I proposed all of the common kinds of renewable energy there is from solar,wind,thermal to biomass but still got nothing approved. Could anyone here please suggest topics for my thesis.. i am really short of time. :frown:. really...
  49. F

    Physics Renewable energy jobs with a BS in physics

    Im graduating with a BS in physics, where I mostly focused on astrophysics. I'm looking to do something different after I graduate, not planning on grad school, at least for the time being. I'm interested in getting a job somehow related to renewable energy technology, and it would also be a...
  50. S

    Undergraduate studies for a career in renewable energy

    I'm right now twenty years old and in my second semester of a physics degree at a school which has a pretty wide variety of engineering and science degrees and an excellent reputation in those fields. I think I would be happy working in almost any science/engineering field, but I'm most...