Dear Rai,

I would say that it would be:

1. Solar (because it´s not finishing)

2. Wind (same reason, but less efficient)

3. Hydrogen cells (same reason, but expensive and demands technology)

4. Bio Fuels (because it´s renewable)

5. Ocean moviments (because it´s not finishing, although it´s low efficiency...)

6. Shale oil (I am not sure!)

7. Geothermal (very limited geographically and low efficiency)

I wouldn´t say that there is many more now, but we can discover other in the future!

Dear Rai,

I expect that the photovoltiac generation will dominate the renewable energy generation. For more details please see the attached link: Method From conventional to renewable energy transformation challenge

I am sure you will like it.

i agree with professor Abdelhalim Zekry

Thanks Prof. Abdelhalim Zekry

Its a good research paper you mentioned

But Prof. Abdelhalim Zekry What about potential of other sources on comparative bases,

If I ask you to rank these renewable sources in order of preference in future market?

Hi

I may arrange them according to the leading aspect in the future, gussing, as following

Solar- Wind-Hydrogen- Hydro - Radiant energy - Biomass - tidal - Geothermal.

I think nuclear energy has no place in future because of its enviromental risks.

Best wishes

Thanks Mostafa A. El-Aasser for contribution in healthy discussion

• Hydro power (often forgotten) is a proven and well-established technology and will certainly continue to be of use, whether in generation or in "buffering". Although its local availability differs greatly.
• I expect wind energy to play a significant role as the cost vs. power figures are quite good.
• PV will continue to play a role - but in comparably small installations.
• Solar thermal energy will play a role mainly in the colder climates where hot water and heating during the winter period require a significant amount of energy.
• Biomass use (especially biomass-ti-liquid) is expected to play a role where high energy density is required - mainly in transportation.
• Geothermal energy is only useful where the ground is comparably "hot". Some additional limitations apply as well. It may regionally play some role, but don't expect too much.
• Tidal energy may locally play some role. But I don't expect much from that.
• Nuclear energy (although not renewable): ??? It is usually forgotten that the nuclear decay happens whether we use this energy or not. It's merely a "redistribution" of the products of the nuclear decay - not some "creation" of such.
• And Hydrogen? Not sure about that. Hydrogen and all products easily synthesized from it (mainly methane, methanol) have a low energy density. And however Hydrogen is "created": it will have to rely on one of the energy sources listed above.

Summarizing: I wouldn't expect a single energy to prevail the same way once fossil fuels did.

Dear Rai,

I would say that it would be:

1. Solar (because it´s not finishing)

2. Wind (same reason, but less efficient)

3. Hydrogen cells (same reason, but expensive and demands technology)

4. Bio Fuels (because it´s renewable)

5. Ocean moviments (because it´s not finishing, although it´s low efficiency...)

6. Shale oil (I am not sure!)

7. Geothermal (very limited geographically and low efficiency)

I wouldn´t say that there is many more now, but we can discover other in the future!

I would just like to take action on the premise because I'm not totally agreeing.

According to UNCTAD statistics on world maritime transport, in fact, oil transport has increased over time as indicated on page 5 of the following report:

http://unctad.org/en/PublicationsLibrary/rmt2017_en.pdf

Dear Rai,

You can find detailed statistics about the world wide electricity production from the different renewable energy sources in addition to their growth trend in the future.Please follow the link for Renewables 2017 Global Status Report: http://www.ren21.net/status-of-renewables/global-status-report/

You will see that largest growing one is the PV power generation led by China and USA.

My expectations is based on the presence of powerful projects world wide to further reduce the cost of solar panels appreciably. If this happens, the pv generation will become the leader of the renewable energy power stations.

In my paper i developed a road amp for the growth of the pv.

Best wishes

What I originally forgot to comment:

Neither shale oil nor shale gas is "renewable". Just considered "unconventional": hard to access, hard to produce and with a large ecological impact. Thus these shale hydrocarbons might be utilized for some time if other non-renewable hydrocarbons become rar(er). But I do not expect wide acceptance for shale hydrocarbons, which might be able to prevent its wider use.

Talking about energy alternatives is not related to the lack of major sources of energy, ie oil, coal and gas. The search for energy alternatives away from oil and gas, as well as coal, can be understood for reasons of the inadmissibility of over-reliance on specific sources, while other alternatives are equally important.

There are hydropower and nuclear power, as well as renewable energy sources such as solar and wind. While there is some kind of nuclear power reservation given the sensitivity of the issue, which may mean the possibility of acquiring bomb-making technology, renewable energy sources such as solar and wind are characterized by continuity and innovation, unlike hydrocarbon resources such as oil and gas, . The environmental, technological and economic conditions of each country play a major role in the choice of renewable energy.

Solar is the next popular and sustainable renewable energy

Thanks all of you worthy researchers for valuable inputs

Good and open question… difficult to answer so directly. What could be the time horizon? What energy users to consider? Maybe there are many feasible scenarios, our world is large and differentiated.

Anyway, I think that will be decisive the effective availability of renewable resources, the particular requirements and constraints of final users, and the costs (capital and O&M), in a broad sense, including the ancillary systems (such as storage and stand by systems, expensive and unavoidable in some cases) and positive impacts (externalities) in the environment (local, global, with a LCA perspective), in the economy (upstream and downstream sectors) and society (labour, decentralization, etc.). Other factors could play also a role: dispatchability, reliability, pre-existent infrastructure.

In my opinion, trying to take into account these elements, in the medium term, for electricity production, isolated or interconnected to the grid, solar energy (mainly direct), wind and bioenergy (by solid wastes and biogas) will play a dominant role. Other resources are more locally feasible, such as geothermal, tides and waves, etc. For moving energy users (people and goods transportation systems), I believe that liquid biofuels (for any modals, including maritime transport and airplanes) and electricity (particularly in small vehicles) will assume most of the duty.

All the best for all of you.

A Hybrid Solar-Wind System. ( if humanity succeeds in avoiding major nuclear disasters).

Oil Shale is not a renewable resource.

Agreed Najib Abou Karaki shale is not renewable resource

Thanks Ayman Yousef

For your value able input

Thanks Dr U. Dreher For your value able input

Thanks Abdullah Hasan Jabbar for following

Thanks Isam Issa Omran For your value able input

Thanks Dickson Adom For your value able input

Thanks Luiz Augusto Horta Nogueira For your value able input

Thanks Najib Abou Karaki For your value able input