@Kenneth: With respect, I do not share all your conclusions and theses. I have the impression, you mix up inconsistent political positions of other people with your own technological insights to justify your own (political) position which is also not fully consistent. First, the term "renewable" is usually referred to the energy source. Strictly speaking, even biofuel is not renewable in your terms because the infrastructure needed might need replacement from time to time. So we could discuss a long time on wordings, but this does not change that different technologies have different impacts on the environment and that it is in priciple a good idea to ask which impacts should be mitigated. It might also be true that in connection with solar panels, harmful substances are set free during production and or during waste management. However, there are very different types of solar panels of very different composition, so it's difficult to generalize at this point. Finally, zero carbon emission is for sure a politically motivated goal. So it might never be reachable - but so is justice. Never be reached as an ideal but nevertheless we pay much effort to try. Technologically speaking, there is no need to remove 50 ppm artificially. Nature removes 100 billion tonnes of CO2 from the atmosphere each year - if emssions could be reduced significantly, we would enable natural processes to regulate CO2 again.

renewable energy can not be competitive for many decades, at least in developing countries

Currently about 90% of the world’s energy demands are met by fossil fuels, which is expected to reduce to around 50% by 2040 with the advent of the renewable energy sources. Increasing price of crude oil and its refined products is a clear indication of the continuing depletion of global non-renewable fossil fuels. In comparison renewable sources are cost effective. I personally think that the world economy will flourish as % use of renewable energy will increase in future.

Regards,

Check following reference:

Article Applications of nanotechnology in renewable energies—A compr...

The urgency to replace fossil fuels will make the transition faster than expected, especially with the deterioration of the climate in many areas (don't ask those impacted by the typhoon Jebi in Japan if they enjoyed the strongest one in the last 25 years and would like to have an even stronger one).

In my area (latitude 50 degrees north) the solar panel industry was non existent, but now it is blossoming. I predict it will replace the conventional energy methods in less than 15 years.

Dear Hari Bhakta Sharma , some of these links may be useful

www.irena.org/-/media/Files/IRENA/Agency/.../IRENA_IEA_REN21_Policies_2018.pdf

https://sites.duke.edu/duketolima/2014/11/26/how-long-will-it-be-for-renewable-energy-to-dominate-the-energy-sector-the-context-challenges/.

https://www.economist.com/finance.../can-the-world-thrive-on-100-renewable-energy

This transition will entail not just money and regulation, but also changes in our behavior and expectations. It will take decades and will fundamentally change the way we live.

Bio Fuel as Kenneth stated is the only true non cyclical renewable energy today. There are others like Thorium, but but all intensive purposes is a no-go because of the sheer amount of investment that is needed to make it commercially viable. China is investing heavy in Thorium. But to answer your question, the reason the transition is taking so long is politics. Partly because the politicians have lied to us due to ignorance saying we have viable renewables when we do not. The other half of the answer is the Power/Oil/Gas Industry. They ultimately do not want renewables. Ever notice how they make a big fanfare about their tiny renewable plants that will barely power a few houses but never scale them up to make them part of the main portfolio?

I will tell you the truth, the only way renewables will make an major impact in the power generation of this country is private renewable companies separate wholly from the existing network; plans develops and executes their own plan commercially nationwide with no help from the existing power industry. They will have to find alternate funding sources as well, private money and make their own way. The existing industry will not help and will not validate renewables no matter how viable. The only thing will make them move is a large disruptor that makes their own business case viable and self validates, plans and builds their own network nationwide. They could do it if they could rally industry to adopt it, because industry is going to be the easiest to make a business case to validate their own projects. I believe this is what Elon Musk is trying (but failing) to do.

The speed of the renewable energy transition does depend on the actors - us - which make it happen.

See a quote from Gandhi: “ If we could change ourselves, the tendencies in the world would also change. As a man changes his own nature, so does the attitude of the world change towards him. This is the divine mystery supreme. A wonderful thing it is and the source of our happiness. We need not wait to see what others do. ”

Have a look at:

Article Historical energy transitions: Speed, prices and system transformation

Depends on what means transition. Never in history, an existing energy source has been completely abandonded yet. E.g. steel and cement production will continue to use fossile fuels for a long time.

This will deprive the financial lobby of energy companies, their approach to new technologies, the level of exhaustion of classic energy sources, and the determination of consumers who will not only accept the imposed policy and calendar of changes by investment funds investing in energy enterprises and global corporations operating in the energy sector .

Your question is very difficult to answer with 100% of certainty. It is expected that for 2040, renewable energy sources will provide 50% of the electricity generated at world level. However, there countries that right now generate electricity using only renewable energy sources during large period of time such as Costa Rica; others are expecting to generate almost all of its electricity using renewable energy sources in the coming decades such as Denmark, while others will have more difficult to increase significantly the role of renewable energy sources in their energy mix during the coming decades. In the case of Cuba, the government expect to generate 24% of its electricity in 2030 using different renewable energy sources, while 76% will generate using oil as fuel.

What is true is that the use of coal will reduce its participation in the energy mix of several countries until 2040 and in the case of Canada the government wants to reduce to 0% by 2030 the use of coal for electricity generation. China will reduce the participation of coal in its energy mix in the coming decades and will increase the use of renewable and nuclear energy for this specific purpose. Oil will continue to reduce its presence in the energy mix in several countries. However. outside of the electrical sector the situation is quite different and coal will continue to be used in the metallurgical sector and oil in the transportation sector after 2040.

The problem should be formulated in other terms: As the problem of the mathematical formulation of optimal multiple objective selection of the equipment (renewable or not), for a given financing, in such a way of optimizing economic, emissions to the environment criteria (and other criteria). In general, or the problem of the optimal economic and social development is solved for all the territories, beginning from the territories and ending on the whole planet or the human specie will disappear

Interesting question..As a researcher, we should work efficiently and fill the gap as soon as possible for the successful renewable energy transition.

The transition will be forever process

@Kenneth: With respect, I do not share all your conclusions and theses. I have the impression, you mix up inconsistent political positions of other people with your own technological insights to justify your own (political) position which is also not fully consistent. First, the term "renewable" is usually referred to the energy source. Strictly speaking, even biofuel is not renewable in your terms because the infrastructure needed might need replacement from time to time. So we could discuss a long time on wordings, but this does not change that different technologies have different impacts on the environment and that it is in priciple a good idea to ask which impacts should be mitigated. It might also be true that in connection with solar panels, harmful substances are set free during production and or during waste management. However, there are very different types of solar panels of very different composition, so it's difficult to generalize at this point. Finally, zero carbon emission is for sure a politically motivated goal. So it might never be reachable - but so is justice. Never be reached as an ideal but nevertheless we pay much effort to try. Technologically speaking, there is no need to remove 50 ppm artificially. Nature removes 100 billion tonnes of CO2 from the atmosphere each year - if emssions could be reduced significantly, we would enable natural processes to regulate CO2 again.

Maybe we should remember some of the tech predictions of the past:

1) "When the Paris Exhibition [of 1878] closes, electric light will close with it and no more will be heard of it." -- Oxford professor Erasmus Wilson.

2) "I think there is a world market for maybe five computers."

Thomas Watson, president of IBM, 1943

3) "Nuclear-powered vacuum cleaners will probably be a reality in 10 years." - Alex Lewyt, president of vacuum cleaner company Lewyt Corp., in the New York Times in 1955.

4) "With over fifteen types of foreign cars already on sale here, the Japanese auto industry isn't likely to carve out a big share of the market for itself." -- Business Week, 1968.

From an economical point of view,the answer depends on the amount of our benefits when using renewable energies rather than fossil fuels and from environmental points of view, it depends on the extent of the we touch the impacts of using fossil fuels.There should be an optimum criteria.

@ Aleš Kralj: you write

" It took an extreme effort for Germany to reach about 20% renewable energy. OECD average being 17%.

Pushing beyond 30% might be impossible for most developed countries with today's and foreseeable technologies (except for sparsely populated like Norway where 50% might realistically be reached)."

Where do you get these numbers from? From https://data.oecd.org/energy/electricity-generation.htm#indicator-chart

I get for 2016 for OECD/Germany/Norway 9.7%/12%/49% with respect to total primary energy supply.

If you rather refer (what I suppose from your OECD number) to % of electrical energy, the share in Norway is already near 100%, Germany reaching 33% in 2017.

I agree that you might call the effort in Germany somewhat extrem, and I repeat that -historically- so far an energy source has been never completely abandoned yet. However, "pushing beyond 30%" is obviously possible with existing technologies and I personably would estimate that 30% for OECD average in 2040 is not unrealistic, without "harming our way of life".

The pace of this transformation, ie the transformation of economies from classical sources based on minerals to renewable energy sources, is determined by many factors. Among these factors, the most frequently mentioned are the economic determinants of the industry, including the companies participating in the extraction and processing of minerals, ie traditional energy sources, climate change, technological progress in the area of ​​innovative solutions in the field of renewable energy sources and research funding policy, which should result in the emergence of these new innovative, ecological, renewable and more economical energy sources. Unfortunately, in individual countries, energy policy and innovation is often very diverse. There is no standardization in this respect. We need homogeneous solutions developed on a supra-national level. In this respect, many positive actions have already been taken, for example in the European Union.

Aleš Kralj

wrote

Arnulf, this prediction... 3) "Nuclear-powered vacuum cleaners will probably be a reality in 10 years." - Alex Lewyt, president of vacuum cleaner company Lewyt Corp., in the New York Times in 1955. ...actually came true. Only that nuclear power was not produced locally. :-)

Answer:

Ok, but then we are alreday using almost a 100% solar energy - with the exception of nuclear power, because without it no fossil fuels and no life would have developed on this planet :)

Aleš,

yes, obviously, there are a lot of terms in this discussion that can be questionable from certain viewpoints, be it "renewable", "energy consumption", "energy production", ..., you could define even "solar energy" in different ways, see above. This is in the nature of things - "nuclear" means something different even in microbiology and physics.

But we have to admit that this is a mixed technical/political discussion and that these terms are well-established in this context and that it is quite clear what is meant by each of them. We should try to stick to this terminology whenever possible because it enables us to participate in the broader public discussion.

In my opinion, the transition depends on the technological saturation that allows the exploitation of renewable sources of energy.

Scientists are clear that we have to eventually migrate to renewable sources of energy, but the transition is political, social, economic and technological. It is complex. I hope that with advances in power electronics, we can accelerate the transition.

The power electronics accompanied by the energy storage sources (batteries) allow to compensate the intermittence, for example, of the wind and the sun. The transition depends on the batteries and the power electronics.

Transition depends upon how need is it.

Aleš Kralj:

I do not agree. In a way, you do the same as the promoters of renewables: You propose to mainly rely on a single source of energy. If we have learned anything general from nuclear, then it is that we should to provide any complex system with suitable redundancy and diversity.

The global energy industry verges on its next energy transition. The 21st century will be characterized by a rising share of cost-competitive renewable technologies, and a move away from carbon-intensive fuels. The critical uncertainty is the pace of the transition.

Read the paper - "The rise of renewables and energy transition: what adaptation strategy for oil companies and oil-exporting countries"

https://www.oxfordenergy.org/wpcms/wp-content/uploads/2018/05/The-rise-of-renewables-and-energy-transition-what-adaptation-strategy-for-oil-companies-and-oil-exporting-countries-MEP-19.pdf

Very interesting paper. With respect to the generally quite conservative position of Hans Werner Sinn I am surprised how positive this paper is about the potential.

I do not believe in nuclear renaissance when I look at recent developments during the last 2 years in China. Maybe costs could go down again, but a massive development in direction of nuclear would e.g. need to revive the breeder/Th concept etc.

I consider it more probable that significant efforts in renewables->liquid or in hydrogen can be made on the same timescale.

Recirculating the carbon using biofuel as a energy source is definitely a solution at the moment but major problem lies in eliminating the carbon that is already there in environment mainly added by burning fossil fuel. We need to think in global context, developing nation rely heavily on coal to run their economy. Realizing complete renewable energy based economy in the word lies more than just getting technology right. It also involves making policy, politics and trade agenda right.

Kenneth M Towe

https://ipcc.ch/news_and_events/pr_181008_P48_spm.shtml

http://www.ipcc.ch/report/sr15/

Transitioning away from our current global energy system is of paramount importance. The speed at which a transition can take place—its timing, or temporal dynamics—is a critical element of consideration. This study therefore investigates the issue of time in global and national energy transitions by asking: What does the mainstream academic literature suggest about the time scale of energy transitions? Additionally, what does some of the more recent empirical data related to transitions say, or challenge, about conventional views? In answering these questions, the article presents a “mainstream” view of energy transitions as long, protracted affairs, often taking decades to centuries to occur. However, the article then offers some empirical evidence that the predominant view of timing may not always be supported by the evidence. With this in mind, the final part of the article argues for more transparent conceptions and definitions of energy transitions, and it asks for analysis that recognizes the causal complexity underlying them.

See complete paper at link:

Article How long will it take? Conceptualizing the temporal dynamics...

Good article.

https://www.youtube.com/watch?v=QI3Al1dpuUY

https://www.youtube.com/watch?v=2JguLRn5v38

http://www.caer.uky.edu/biofuels/research/research.shtml

UKY has made a C02 capture and mitigate system using a bio-fuel reactor. It has been proposed to add these to all coal and gas plants, reducing their emissions to zero. This could enable a time buffer to transition to more renewables while we curb our emissions on a large scale.

http://blog.policy.manchester.ac.uk/posts/2018/10/response-to-the-ipcc-1-5c-special-report/

Interesting reply to latest IPCC report .

Great contributions by the scholars on here.

Renewable energies are those that we get through the energy currents that are spontaneously present in nature. They are solar, wind, water and biomass. Ocean energy, tidal energy, and geothermal energy are also energy renewable.

That the transition from a fossil-based global energy system to a solar-based system requires entirely new technologies and modest and achievable steps in the technologies already in use or being developed. Unlike nuclear power plants, each of which takes six to 10 years to build, renewable energy technologies are small and modular in general. 80 MW solar thermal power plants are usually built between six months and eight years. As a result, new technologies could develop rapidly within a decade, and new nuclear technologies could require at least two decades to be put into commercial use.

I think this will help. Also it is a common practice to reuse Methane from wastewater treatment plants for Electricity production on large scale, also recycling Solid wastes and reusing Solid wastes for Electricity production on large scale especially for installations in the desert where the Sanitary Landfill is situated out side the town( approximately 6 km away from residential areas). This and other renewable energies will eliminate the use to Fossil Fuel.

"complete" in your question can't be achieved as evident from history everything has a scope for further.....

Tell me one "technology" or "area" upto date...which is complete ?

It will never happen within our life time

Regardless of when the transition takes place, we have to make sure of one thing here. Each and every human being, must contribute towards a sustainable life on this planet and must show responsibility to use renewable "actions" each and every hour of the day. Otherwise the coming generations would think of us as very selfish individuals, that sucked up all the resources that this planet had, and left a non-breathable/water-less waste of an Earth for them.

While this debate is going on here, I have the impression is getting more and more black-whitish instead of generating insight. Here are political issues and technological issues and instead of deconvoluting this, we all just take part in mingling up everything. Maybe just a few (hopefully) new pinpoints:

I think, either solution that relies on a single technical concept will not be possible. Proposals like 80% nuclear, complete abandoning of fossile or removing a greater part of human-produced CO2 from the atmosphere by technical means... all these are things that I do not think will happen in our lifetime or in the lifetime of our children.

Therefore, I think, we should recognize that each of those proposals (among many others) is not pure technological, but also political.

So all these proposals play in the same league as "controlling climate" (which is, as was pointed out, of course a political shortening). I think "controlling climate" is nothing more (and nothing less) than stressing that human activities at a certain point might shift existing equilibria into regions where we do not want to have them.

in detail:

• carbon storage seems not a good option for the billions and billions of tons of CO2 in the atmosphere. But: reducing the amount of fossile fuel that is used, we might come into a region where self-regulating processes will help stabilizing CO2 at least at a certain level
• solar/wind will always be volatile, so their success is depending on storage and/or additional sources. Storage possibilties might be coupled with mobility issues, once vehicles are driven by electric or hydrogen.
• speaking of which: While some in this discussion stretched that energy prices should not be too high, my personal impression is that at least in my society, the prices are still too low to influence behaviour significantly - looking at how many people are driving around in cars that weigh 30 times more than the transported persons.

To go back to the original question: I do not know how long

renewable energy transition will take. I do also not know if a complete (what ever this is) renewable energy transition is possible. I also do doubt that a complete (what ever this is) renewable energy transition is even necessary. But I think it is necessary to think about how we can come to a human acting that is more in equilibrium with the world, ensuring safety and security for the next generations. Technologies might be part of a solution, but not the only one.

Turning Wastewater into Energy

http://www.metrovancouver.org/services/liquid-waste/innovation-wasterwater-reuse/wastewater-energy/Pages/default.aspx

I like the Arnulf Jäger-Waldau answer. Most predictions are not accurate. But very few are. U.S and Canada seemed to be on track in terms of replacing fossil fuel with renewable energy sources. But now it is in opposite direction. To add more wood to the fire, Canada is even expanding its fossil fuel industry and cancelling support of renewable energy industry. It is all for the sake of 'economy' but the reality is that it is for a quick cash. Note that fossil fuel can be categorized as renewable energy because it comes from plant and animal kingdom. It just takes a very long process to make it. But human appetite for energy is always there and quick therefore fossils are treated as non-renewable (if you think in terms of creation and destruction of fossils). Regarding your question, the answer is : as long as human species (prefer to call it homo rex instead of homo sapiens) exist.

"...... the answer is : as long as human species (prefer to call it homo rex instead of homo sapiens) exist" . Adam Szewczyk. This seems to be correct.

With a little modification - both the energies, nonrenewable and renewable, will be used parallely to meet the growing demand. Human can not leave the nonrenewable resources till the reserves exit.

Aleš :

Yes, one of my supervisors once said fatalistically: It is not the question whether the fossile resources are burnt. In any scenario, humankind will probably use them until they are used up completely.

Alltogether I fear, we can not rely on technology alone. We have to ask questions of efficiency and sufficiency. At least, in the private market there are still big improvements to be made. To stay with my example: 40% of drives are < 5km. The difference of emissions needed for this distance (basically within the same time) reaches from nearly zero if you use a bicycle, up to an amount of fairly above 1 kg CO2 if you use an SUV as a single person and calculate life-cycle emissions. And at least in Germany too many people think they can solve the problem if they just replace the SUV with a Tesla which has no local CO2 emissions but needs an ridiculous amount of ressource in production.

Dear Erik, Ales, and Asit,

Agreed!!

In 3rd world countries, people can't think about shifting to renewable energy sources, if they haven't yet fully utilized the existing resources to their full potential. Carbon is one of the most abundant material on Earth's crust and its abundance will continue to increase as long as there is organic life on this planet. One needs to open all facets of utilization of Carbon and its many forms, in renewable energy sector too.

WE need to find a balance between "energy return on energy investment" which is cost effective for a region, and that is now possible only by a combination of non-renewable and renewable energy techs.

Ales

I'm personally in favour of bicycles. It might be dangerous (is it really?), but at least if I die, I die relatively healthy. ;-)

Yes... of course any saved money can be used to buy other energy-consuming things... but this is true for any saving... so in way you are saying , CO2-saving techniques are more effective when they are expensive (sorry, I couldn't leave out this punchline). Seriously: the price of anything that is luxury in the widest sense can be quite independent from energy consumption. For example, a McDonalds meal has a similar energetic footprint as a three-star-meal that can cost 10 or 20 times.

Kenneth M Towe

I already did say there is no simple technical solution. Nobody said everyone should cycle all winter (although I know people that do), and even if everyone did everytime, we can probably not abandon fossile at least for heatand process heat. But more people cycling more often might contribute. Like wind. Like sun. Like coal (probably for along time), like nuclear (probably for at least the next 40 years, even if new builds were stopped immediately), like decreasing growth of population (prognoses of the1990ies were mostly overestimated), ...

Aleš

I agree on many points, although

a) at least within Cologne center, a bicycle is the fastest way to get around.

b) if the goal is economic growth without increasing exergy, it is obviously possible, even at a high level. During the last 10 years, Germany had an average of almost 2% growth at stagnating/slightly decreasing exergy.

Kenneth,

I stand on the question on neither side but I try to bring in both skepticism and rationalism.

Politics needs goals. Even if from my view, technicallly, a goal is unreachable, I admit that it can utilized to bring people to act together. I am not really a fan of this, if this happens unreflected, but we have to accept mass psychology at some point.

Same as I am not a fan of nationalism but I admit that the national movements of 19th century Europe were coupled with increasing wealth for many.

I do not think that politics follows "a few scientists". Politics follows science main stream (or at least tries to). Science mainstream may be flawed in some cases -also scientists can be wrong- and we also have to accept that the state of the art of science is always under discussion. So, if we try to base decisions on the state of the art, they also might be flawed, but, globally this is the best we can reach.

I am happy that at least, scientists are asked by politics at all.

So we as scientists should -of course- participate to make our points. But we should adopt that also our own viewpoint might be not 100% precise but in many cases has a political component. And we should accept that we never can reach "truth" in political processes as we reach "truth" in science.

The transition will end with the end of all fossil fuels. That is, with the disappearance of the last oliman (Like the last of the Mohicans).

Herr Braun,

yes, we can.

Science is never about certainty, it is always on minimizing the uncertainty.