I recently heard a very interesting talk on that by Dr. Hans-Martin Henning of Fraunhofer ISE, they built a model to evaluate just this for the year 2050:

http://www.ise.fraunhofer.de/de/veroeffentlichungen/veroeffentlichungen-pdf-dateien/studien-und-konzeptpapiere/studie-energiesystem-deutschland-2050.pdf

there are still problems integrating power from thermal power plants since when thermal plants once turned off need 8 hrs to come to operation again. and power from renewable energy sources is never integrated to diesel generation as when diesel generators are not fully utilized they operate under low efficiencies.

Coming to hybrid systems solar-wind is excellent combination as commercially they have reached to 0.1$/unit in India.

There are many ideas which could be incorporated such as solarisation of wind farms, on shore wind energy harnessing, rooftop solar for utmost utilisation of renewable energy.

It is expected that solar and wind costs will still go down further and become a competition to conventional electricity supply unit.

demand security can be enhanced by proper management of hybrid systems and respective central governing bodies can play an important role in providing policies and documentation to people regarding security etc.

Agencies can be setup to look after all these matters.

Vasco and Sujan!

Thank you for your input. I would like to ask your general oppinion on H2 or Hydrogene fuel cells as medium capacity storage devices. Depending on market affordability I see quite potential to circumvene the problems arising out of fluctuations from especially solar/wind generation.

I agree on that. Another possibility, despite its often discussed low level of efficiency, could be power-to-gas, which also offers good storage capabilities combined with ease of use.

I think, H2 as a pure storage device is not very efficient with respect to Pumped-storage hydroelectricity etc.. H2 storage could be interesting if there is a fleet of H2 burning devices anyway (e.g. cars). The same is true for batteries - not very effective but maybe useful to flatten the fluctuations of solar/wind if there is a huge number of small devices out there anyway. Cars are usually moved only 1h a day or so. The refueling of the battery/hydrogen tank can be at any time duringthe remaining 23 hours depending on availability.

I appreciate your answers. I want to just add that hydrogen fuel cells come with 80 to 90% efficiency. and the main problem with them is hydrogen. hydrogen has huge energy but research is still being done to solve the problems related to its storage. they can be integrated with solar/wind as they dont depend on any environmental factors. just by increasing the fuel input, we can get rated output. And we even dont have problems with with under or over utilisation. coming to small scale portable applications, direct methanol fuel cell(DMFC) would play a promising role as the come in portable sizes and problem of hydrogen storage is eliminated but their efficiency is just 30-40%.

Coming to face the intermittency due the fluctuations in solar and wind, SUPERCAPACITORS can be used which have very high power density.

Compared to batteries, supercapacitors would be economical and larger power can be pumped in lesser time.

Vasco. can u just give a small explanation how that works 'power to gas'??

I am no technical expert on this, but the term power-to-gas is used to describe the means to convert H2 gained by (electrically) hydrolysed Hydrogen into Methane by addding Carbon (see http://en.wikipedia.org/wiki/Methanation), which then can be used (and stored) just like natural gas from non-renewable sources.

Dear Erik,

thanks for the input - I was thinking of H2 fuel cells that work in both direction.

basic idea "as usual" to use excessive VRE (Variable Renewable-Energy) in the grids (local / small area) obviously on DC or HPDC level to fill the storage cylinders with H2. In an ideal smart grid the H2 burning cells would immediately step into action upon rising demand at shrinking solar/wind supply. Later on I would like to introduce my new concept of heat to power which we currently got patented and have the first prototypes running where I am working on the testing sites at the moment.

Dear colleagues,

perhaps the link below to a recent paper on automotive fuel cell technology and hydrogen infrastructure might address some issues already raised in this discussion thread (e.g. hydrogen as chemical storage medium for renewables, power-to-gas). It would be great if you consider the piece interesting.

Best Regards

Ulrich

Article Fuel cell electric vehicles and hydrogen infrastructure: Status 2012

In the majority of the countries, the best way to satisfy the foreseeable increase in energy demand is to use all available energy sources for heating and electricity generation. In several countries, exist the possibility to increase in a significant manner the use of renewable for heating and electricity generation while in others this increase could be lower. It is expected that the use of renewable for generation of electricity and heating at European level could reach 27 % in 2030. Some countries could reach a higher level, such as Sweden (49 %), followed by Latvia (40 %), Finland (38 %), Austria (34 %), Portugal (31 %), and perhaps other a lower level such as Estonia and Slovenia (25 %).

In any case, there is no real possibility that renewable substitute all other energy sources for the generation of electricity and heating in almost all countries before 2050.

One of the reasons is the variability of most of the renewable energy sources and their dependency on weather conditions and geographic location, among others.

Jorge!

Thank you for the input. It made it clear for me to distinguish between the two main power needs:

1) Heating Power

2) Electrical Power

So I need to refocus the question to

2.1) Generation/Transformation/Storage

2.2) Transmission/Distribution/Supply

2.3) Usage/Consumption/Demand

of Electrical Energy, where the Generation should be done by 100% Renewable Energy Sources.

I think it is important to distinguish between the two power systems as the infrastructure and logistics needed for either one of the two are very different and in case of heating the consumption needs are even more multivariate as the quantitative side is highly dependent on the consumers' infrastructure.

In many cases it is better to have power plants that generate electricity and heating. In the case of the generation of electricity, it seems to me very difficult, for the majority of countries, to have a high level of renewable in their energy mix before 2050. Very few countries could reach a high level of renewable in their energy mix, but we could count them using our fingers. In Europe up to 2030, the major level of renewable in the energy mix will be 49 % in Sweden. According to some public figure, Denmark is one of the countries that expect to reach a higher level of renewables in its energy mix during the coming decades, but this is the exception to the rule.

Germany is also pushing to have a high level of renewables in its energy mix, but the cost to achieve that is too high and perhaps could not be supported by the government in the future.

In many countries, gas is the energy source that could have a bigger role in the generation of electricity, in addition to coal and, in some countries, nuclear energy. Many countries are reducing the participation of oil in their energy mix, but in some of them, the use of this energy source for the generation of electricity will be important at least until 2050.

You can find updated information on the use of renewable in some of my books and articles already published in 2013 and listed in my page in Reserchgate.

I attach an abstract of my communication in a recent conference dealing with hydrogen for flexible electricty storage at large scales: this concept uses the potentials of existing power systems and the properties of H2 as energy carrier; it can increase the efficiency of the system and integration of additional renewable energy by using surplus electricity at low prices and leveling the power plant balances. Please use the reference for more information or keep in touch for new results to be published soon.

Thank you all for the contributions so far.

Have you considered storage as an option ?

Effective storage technologies on the one hand is a key solution to solve the intermittance problem of the two commonly used RES wind/pv, to broaden the range of sources is another main target - the efficient transformation of heat into power as well as heat storage solutions at the same time seems to be an interesting lead worth following.

Agree with your comment. But for large scale applications and considering economics, compressed air energy storage (CAES) and pumped hydrostatic technologies would be worth investigation as well since battery storage will not be a viable option primarily due to economics...Any thoughts ?

Scalability obviously is an issue [Storage Capacity] as are Charging and Discharging Speed, not to mention the Demand Response Rate. Obiously where available Pumped Hydro-Storage [PHS] is a very successfull model taken into consideration the above mentioned points. New Zealand e.g. has PHS capacities of approx. 5.000 GWhs.

Small Battery Packs and home installations serve very local equilibrium needs as Distributed Energy Storage [DES] and Smart Grid Management Technology [SGM or SGT] might be important points in the integration efforts of VRES into the electricity distribution grids in developped countries. CAES are as I reckon high power but fast discharging tools - so one of my tasks will be to prepare the list of possible storage systems rated with their different characteristics, where regional availability is an important factor.

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The easiest and most economical is the relocation of electro-intensive industries to places where there hydraulic energy to be exploited, for example, in central Africa (Congo River) .

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I do not see near horizon generation and storage of 100% wind and solar energy for electro-intensive industries.

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I reckon that electro-intensive industries usually come with excessive heat. I am working on a project to retreive this "waste heat" and convert it into usable energy or store it as heat - obviously electro-intensive industries will have a 24/365 or close to that operations time - at the same time diminish the needs for excessive energy in the form of cooling - which seems to double the energy consumption of electro-intensive industries. From geo-political, strategical and monetary reasonc relocation might not be at hand. e.g.: Aluminium production transfer from China to Brazil will maybe have major negative impacts on the environment - maybe higher than potential profits even if the needed energy would be produced by RES.

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87% of the energy generated in Brazil comes from hydropower. While in Norway is considered clean hydropower in Brazil is considered as a pollutant? Did not quite understand the geopolitical reasons?

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Not wanting to transfer part of the industrial complex are not for reasons of the environment!

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There is a new report by the IEA that comes to the conclusion that least 45% of variable renewables (wind, solar) can be integrated into most grids.

http://www.businessspectator.com.au/article/2014/2/27/renewable-energy/iea-grid-can-handle-45-solar-wind-minimal-cost

http://www.iea.org/newsroomandevents/pressreleases/2014/february/name,47513,en.html

www.iea.org/newsroomandevents/speeches/140225_GIVAR_PC_Slides_final.pdf

www.iea.org/Textbase/npsum/GIVAR2014sum.pdf

The conclusion is clear from the IEA:

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"The report says that for any country, integrating the first 5-10 percent of VRE generation poses no technical or economic challenges at all, provided that three conditions are met: uncontrolled local “hot spots” of VRE deployment must be avoided, VRE must contribute to stabilising the grid when needed, and VRE forecasts must be used effectively..".

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On the other hand:

"Going beyond the first few percent of shares to reach more than 30 percent will require a transformation of the system, However ....."

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One thing is certain, any system of power generation that exceed 15 to 20 percent, requires the construction of backup systems, ie doubles the cost.

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Thank you both for the reference with IEA. Maybe the (necessary) transformation of system should be taken into consideration when decentralizing energy supply logistics. On the other hand - if taken the planetary situation into consideration - the lessons learned from the northern hemisphere or industrialized countries can be vital for the southern hemisphere or developping countries that are in need of energisation anyway. So if systems need to be set up there (as there are none) maybe it will be a start to take the right (I) (V) (F) RES steps including storage and distribution (grid / onNet) solutions.

@Rogero:

In your first quote you made a rather essential typo:

" The report says that for any country, integrating the first 5-10 percent of VRE generation poses NO technical or economic challenges at all,"

The last conclusion is your own and not in agreement with the IEA report:

"The IEA report finds that if you assume the existing shape of the system can’t be changed then the integration costs of something like 45 per cent wind and solar is very expensive at as much as $US33 per megawatt-hour. However, if you allow for adjustment of the rest of the generation mix over time and draw upon demand management, then the cost at 45 per cent market share is about $US11 per megawatt-hour and just $US6 at 30 per cent renewables."

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@ Jethro

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As the quote IEA is really in error, and the correction makes it clearer my point of view, I will correct the text by putting the phrase in full (Ctrl C, Ctrl V).

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Attention to reference 15% to 20% is outside the quotation marks, so it's not a quote from the IEA.

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These values ​​are easy to verify. When these limits are reached means that the rest of the mesh is responsible for 85% to 80%, ie "reservation system" is given by a ratio of percentages and can be counted with maximum values ​​around 60% of installed power in the system.

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@Rogerio

As the IEA study illustrates, the scientific debate about the grid integration of renewables has moved on beyond such simple rules of thumb. There have been done hundreds of studies on the grid integration of renewables and they mostly show that much more is possible than what conventional wisdom expected.

https://www.nrel.gov/docs/fy12osti/53732.pdf