Energy Systems - Science topic

Narjes Azizi The constraints include a limited supply, limited acceptable geographical locations, transmission losses, and the danger of decreasing subterranean well steam resources.

In the literature, common potential barriers to geothermal district heating system (GDHS) development include a lack of awareness of geothermal energy system benefits among local governments, the complexity and risk associated with GDHS projects, and a lack of local knowledge required to manage these complex issues.

Hello Diego Garcia-Gusano,

we used MESSAGE on city the city scale of Vienna in our group.

Besides I could also recommend the following papers on city scales using modeling frameworks.

Best regards,

Daniel Horak

Maybe you can google Kalman filter for distributed parameter systems (continuous) or for 2D systems (discrete).

Hi all, I am also struggling with simulating the parabolic trough collector in aspen . kindly assist me. I want it to act as a preheater at a certain location in Kenya.

Many thanks@Deep for your comments. They're all in line with our knowledge in house. Would appreciate if there's more specific challenge or gap etc.

I recommend that you review these manuscripts. This is a list of scientific contributions selected from the Scopus Database. I hope this information will be of great use to you.

Good morning Johannes Morfeldt

Thank you for your reply.

We are aiming at modelling the life cycle environmental impacts of alternative decarbonisation scenarios for the iron and steel industry. To do so, we are exploring the adaptation and integration of LCI/LCIA data into LEAP.

I will read your article for additional insights based on your approach. Thank you very much for sharing it!

All the best,

Joan Manuel

Dear Dr. Grigorios Kyriakopoulos,

I appreciate you for your helpful answer in enumerating an energy-efficient and eco-friendly energy coupling technology that is beneficial in exploiting geothermal energy.

Best regards,

Omid

Dear Ssennoga Twaha , definitely right!

In Myanmar, the renewables based hybrid system is the feasible option for electrifying the remote and rural communities.

You can find my research articles on R^G about off-grid Mini-grids in Myanmar.

Good answer by Debrayan Bravo Hidalgo

Dear Prof. Messaoudi,

I am interested to work with you since Renewable energy is one of my main and favorite research field. I have also completed a research in past based on renewable energy sources and their effectiveness.

Alternative and Renewable energy, solar, wind and geothermal power, brining down prices in the process about free of cost and highly demand world wide is.

Please see my profile

Best regards

Dear Taofeek,

The concept of phasor mode is that the frequency is constant. In this case, the inverter will work as if it were a transformer. However, as your goal is to create a control algorithm, I think it is better to use the continuous/discrete mode.

Best Regards.

Dear Lucas Schneider ,

Hope you are well!

I will give a conceptual answer and then you can implement.

You have the input flow and the out flow from a hydrogen tank and you want to determine is size given the maximum pressure.

You can get the maximum stored hydrogen by calculating maximum the difference between the total input flow and the total output flow

Hence:

The maximum stored hydrogen= Maximum( total input flow -total out[put flow)

So you need three columns for the total input flow, the total output flow and the difference and then the maximum difference which will be the maximum stored hydrogen, MSH.

Assume that the units of this stored hydrogen is in cubic meter at standard conditions of pressure and temperature.

Then all what do you need to get the volume V of the tank is to divide MSH by the maximum pressure P^.

Then you need to check only the minimum level of the gas by similarly calculating

the minimum stored hydrogen, MinSH divided by the calculated volume of the tank V, That is the minimum pressure= MinSH/V.

Best wishes

Thanks , I contacted the journal and even after 4 months, the editor is still waiting for reviews from 1 more reviewer. Pretty slow indeed.

Did you check the possibilities of Homer pro Biomass Module to integrate this Special fiel combination?

[(Wm * Tref)/Vd ] - [ Ia] ----> PI controller and pulse generator, you will find the control of DC/DC converter

Best regard

Dear and Detlef Ruschin

Thank you so much for your reply and the references mentioned.

I can see a link of observational and informational trust with the concept of dependability. That cames from system engineering as a measuring tool based on integrity, security, reliability. I will take this into account in my research (if you have any other reference it will be amazing if you remind to share here).

However, when it comes to socio-technical systems (where there is an interdependency), cognitive factors should be considered. As humans are barely predictive, trust in society will always be a dynamic parameter. Actions will lead to reflection + reaction, from an individual (trustor) towards the trustee. The individual will base the judgement on his subjective perceptions of what is considerer trustworthy or not. Such perception can also change based on his personal experience and how external factors influence/impact the trustor.

Dear Amir Hossein Zakeri ,

The values of the electricity consumption is given per hour averaged on the whole month. So

Mathematically Average hourly consumption along one month of the year=

SUN one hour consumption in kwh from day one to the end of the month. divided by the numbers of days in month. January is the highest consumption may be due to heating. Some hours in the summer days the consumption increases because of air conditioning at the nun times.

Best wishes

Dear Md. Nasimul Islam Maruf ,

I think the major source will be direct solar heaters. Especially in the European countries in the south and east of Europe where they are rich with solar radiation.

For very controlled heating for industry one has to use the photovoltaic generators.

Best wishes

Dear Md. Nasimul Islam Maruf ,

I am not very aware of the availability of land for solar power installations in Bangladesh. The interesting with the increasing the solar cell conversion efficeincy, the area required will be reduced. The other important factor is increasing the utilization effeciency of the electricity by smart control one may reduce required electricity supply.

Best wishes

Also check https://www.modernpowersystems.com/features/featurewhen-things-go-wrong-identifying-combined-cycle-problem-areas/

A changing climate has potential effects on the electricity sector, for example with respect to hydro-electric flow (in summer, and from snow melt), from wind resources, and from water abstraction for large generation plant.

I attach a report (sorry, in French) on this aspect in Swizereland.

Dear Taskina Nasrin

Yes, it is possible by using different programming and software as:

1 RETScreen

2 LEAP

3 HYSIM

4 iHOGA

5 ARES

6 SOMES

7 RAPSIM

8 Hybrid2

9 INSEL

10 HySys

11 Dymola/Modelica

12 HOMER

13 Matlab

Best regards

LEDS-EEP City Energy Planning Toolkit By:

Judit Bálint, Eduardas Kazakevicius, Thor Morante Brigneti

You can try to visit

specify the output format and location on the Publish settings pane

Thank you Mr. Edwin for your guidance

I can see why you might not want to dive deep into chemical aspects of a process, but why not thermal? Even so, there are purely electrical aspects of power generation that can be improved through further study. Have you considered power factor control? That's the phase between the voltage and current on a three-phase power grid. While it might be close to unity in the US, Canada, and parts of Europe, it's often quite variable in developing countries, which can pose challenges. Frequency control (50/60 Hz) is another issue that's entirely electrical. How might waste products fit into this? What about load following using landfill gas only during periods of peak demand? What about only processing waste during periods of off-peak demand? This could be as simple as only refilling the water tank on the hill in the middle of the night when demand for power is lowest.

Try QUTIP first and then qiskit IBM

Wingate (30s all out in a bike using p.e. 7.5%-10% of your body weight as resistance). it will use that energy system, at least for the first part of the exercise.

You can use MolAICal ( https://molaical.github.io) to calculate the MM/GBSA based on the simulated results of NAMD2. Please see the tutorial: MM/GBSA tutorial by NAMD and MolAICal in the website: https://molaical.github.io/tutorial.html

Dear Irfan Shahid

Please take a look at these sites

Best regards

https://www.youtube.com/watch?v=cUmAM9laViU

https://www.youtube.com/watch?v=oJzjPJ9_g1o

https://www.digsilent.de/en/optimal-power-flow.html

As much as you input data for SVM, you will get more accuracy for your model.

Dear Hooman,

I think you can use the "loop" as this form:

Dear Emmanuel Vincent Philip,

This link maybe useful for :

Dear Dawid,

I would advise use MATLAB instead of Fortran code for steam cycle performance.

Power plant can use couple of process simulators such as e.g. Aspen Plus, Unisim, and Pro II. . To evaluate the model’s performance, its predictions may be compared with those of an equivalent model from Gate Cycle or other cycle. Use the Steam table for steam, count enthalpy values of cycle performance, and predict the inlet temperature, mark steam deviations and efficiency range. Just assume, the relative deviations in the plant power output and efficiency must be less than 0.65% for 100% loads. Use MTALAB, it can solve your issue(Reference: Aklilu and Gilani adopted the normalized parameters from to describe the characteristics of compressor and turbine and developed a simulation model in MATLAB to identify the plant operation mode from field data. Zhang et al).

The simulation can follow the recycle modules.

The following assumptions perhaps you have made for simulating the pressure in power plant using Aspen.

1. Plant at Steady state (2) Fuel combustion (3) Cooling water flow (4) No water leak.

Refer the site:

file:///C:/Users/3020/Cookies/Desktop/Downloads/SimulatingcombinedcyclegasturbinepowerplantsinAspenHYSYS.pdf

Ashish

When the compressor stops and only the fans run, the power consumption can be one tenth of the total consumption of the air conditioning system. This is because the mechanical compression process requires much more energy than fans use to move air through the exchangers. Basic knowledge of thermodynamic theories explains this difference between the consumption of the cooling system while only the fans operate.

And if the model is not stochastic?

Check out Leon Lasdon's book on large-scale optimisation, called

Optimization theory for large systems

Dear Muhammed

Surely you should consider the worst-case scenario and optimize the system based on the worst-case, you must use an intelligent algorithm that attempts to give you the optimum number of elements of the hybrid system. You can visit my account and see my papers if you need any question do not hesitate.

Best regards

There are many components to a successful research study and many questions that researchers must consider in order to develop a relevant and viable project.

In order to find a topic, the researcher must first identify the goal of their research. Is it to improve or advance a program or intervention, to establish basic data on an unknown topic, or instead to test an educational innovation? Answering this broad question will help you to hone the possible topics of your study.

Oftentimes, students as well as professional researchers discover their topics in a variety of conventional and unconventional ways. Many researchers find that their personal interests and experiences help to narrow their topic. For students, previous classes and course material are often the source of research ideas.

DlgSILENT offers excellent tools for analyzing all power generation components and offers a vast array of functionality perfectly suited to provides comprehensive modelling features for studying all kinds of electrical networks.

DlgSILENT provides all the necessary functionality to conduct complex studies for the integration of renewable generation into distribution, transmission and industrial networks, which is nowadays one of the key issues in network planning and analysis. A full set of tools is provided to undertake the wide range of studies required for grid connection and grid impact analysis of wind parks, PV generation and all other renewable energy power plants. Recurring tasks can easily be automated using scripting tools, to streamline the analysis process.

Cybersecurity of Power and Energy Systems is a topic with many questions yet to be answered. This research area is roughly 50% on computer science and 50% on power and energy systems.

Also, Power Quality of Energy Systems with High Penetration of Renewable Energy is another important area with many unanswered questions.

Although the topic has been well studied in many papers

But there are still important topics. However, any a new study can be essential and useful.

Look at topics of recent papers and try to apply some of these studies on your country or countries where the research has not taken place. Any subject can be of benefit in changing the goal type, reliability, and the methods used to reach the solution. A multi-goals paper will be valuable.

Look at the topics of my papers on RG these researches can guide you to a new idea.

Omar Hazem MOHAMMED

I think Ihtishamul Haq is working on Aspen plus, you can consult him.

Thanks

Dear Balamurugan,

There is complete matlab code and mode extraction for the solar cells and solar panels in the book chapter:

Best wishes

Dear: Kitumba Fredrick Lugard :

I'm attaching a reference from a book in Semiconductor Physics from the University of Berkeley, this book is very basic but it has some information I think it can help.

Inside you will be able to find some expressions to compute the Barrier Height for a Schottky barrier, as you where looking for.

As for the Built-in Potential, I'm affraid this one is more subtle and not as straightforward ...

There is a very simple method describe in one example included in this book. They ask you to plot a V vs. 1/C² plot. Where V is the Applied Voltage for the junction and C is the junction's Capacitance. And then, the method points one do have to adjust the experimental data points to a liner model, one with positive slope, from which one you would be able to obtein the Built-in Potential.

I sometime ago tried to do this, but there are so much practical complications, and they don't explained further, I traried to search it on other references, but never been able to find it, I don't know if it can be helpful, but anyways I recommend you to give it a look.

The issue with the above mentioned method to plot the Voltage vs. Capacitance is that I don't think the experimental points for these measurements (Voltage-Capacitance) provide you data you can adjust fairly to a linear model, at the interested region. So if you look for these methods (or characterization methods) in articles in the literature, you will find other models (a square, cubic , etc.. ) more suitables for these experiments. I'm trying to remember that a square model can be fitted more accurately with the measurements. But when I did these characterizations I was interested in getting the Built-in Potential for a p-n junction, not a Schottky.

Maybe the IEEE European Low Voltage Test Feeder case helps you : https://ewh.ieee.org/soc/pes/dsacom/testfeeders/. It consists of 55 residential buildings and a radial networkwith 4 branches. This paper used it as case study:

Dear Katyal

The second law of thermodynamics known as a non-reversible law, that means at any movement of the system boundary there is an entropy generation this called the entropy generation due to the work. As well as the heat transfer to the system causes two types of entropy, the first one is the entropy generation and the second is the entropy transport.

The entropy generation due to work and heat always greater than zero. While the entropy transport due to the heat transfer can be negative or positive depending on the direction of heat flow. Thus, the heat flow to the system produced useful work and part of the heat is lost as entropy generation and entropy transport.

The matter is not complicated as if you know the conversion efficiency, then you can express the output power po as a function of fuel consumption. then

po= Eta pi, where pi is the fuel consumption rate in KWh and Eta is the conversion efficeincy. I think there are such curves or values of the efficiency. You can also take the po as a function of fuel curves and curve fit them and use them in your model.

Best wishes

Thanks!!!!!!!

I will do ASAP!

Dear Dr. Algburi,

As known, dust and high temperature effect significantly on the electrical performance of the photovoltaic systems. In my opinion gulf area or sea are better options. Moreover, maintenance cost will be higher in a power plant in the desert. Sea breeze can decrease the surface temperature of the solar panels. On the other hand, photovoltaic-thermal (PV-T) systems can be utilized to produce both thermal and electrical energy. With this technology, PV temperature also can be decreased. To make better decision, prototype systems should be investigated in various regions.

Regards

You will still have to minimize with appropriate constraints later, otherwise the geometries may be incompatible with the subsequent dynamics that require the use of constraints.

I was too harsh in my comments about EBSILON. My team did find that it was the best currently available alternative to GateCycle V5.61. EBSILON has many excellent features and additional capabilities. I faced the challenge of being given only 80 hours (determined by Sales & Marketing) to develop a system model, validation cases, and a complete set of correction curves. Our director insisted on 0.1%/0.1° agreement with design heat balances and 0.2%/0.5° agreement across the range of corrections, demonstrated by random cases. This was very difficult to achieve with GateCycle, but much more so with EBSILON, given the available controls and adjustments. Forcing a model to fit the EPC's heat balances, which contain multiple unspecified and proprietary margins, is a daunting task indeed. This raises an issue of much debate: how I (the performance testing engineer) think a system will perform vs. how they (the EPC's engineers) are willing to guarantee it will perform (including possible liquidated damages). If I am not liable for the liquidated damages, I don't get to decide how the system "should" perform, which means I don't get to loosely match the information provided. This is implied in ASME PTC-46, depending on who you ask. As a performance testing contractor, it was my responsibility to represent as accurately as possible what the EPC committed to delivering, not how I thought a system was going to perform. When a big discrepancy arose (and they occasionally did), I informed the parties that there might be a problem meeting the guarantees. If the performance test proved otherwise, that's OK. EPC's engineers will tell you stories like... This vendor always come up 5% (or 1°) short, so we just add 6% (or 1.5°). We save $20M on the project, come in lowest bidder, and still achieve the guarantees without getting sued. If time were not such a hard constraint for me (as in a nuclear plant, for instance) or if agreement with an EPC's margins were negotiable or if I were designing the system (rather than working with someone else's design), the evaluation criteria would be different, as would my conclusion. The fit between GateCycle V5.61 and the performance testing company I worked for was fortuitous indeed. I think 80 hours is unreasonable for such a complex task, but that's the market reality I had to work with. I should think EBSILON an excellent choice for many other circumstances and applications.

Both technologies are older than combustion system. First fuel cell was designed by Wiliem Grove in 1839 based on theoretical work of Christian Friedrich Schönbein in 1838 and first electric vehicle come up in 1835 and constructed by Sibrandus Stratinghem and Christopher Becker.

I can say that It doesn't matter who win this battle, the winner will be people and Earth's environment because we will have traffic without pollution and CO2 neutral as it is supposed. However, I can continue by many arguments why both solutions might not be so clean as we think at the first sight. It depends how the electricity is produced, how much energy is needed for producing of batteries and influence on environment in overall. And similar for fuel cell vehicles, it depends how the hydrogen is produced because decomposition of natural gas, which is most frequent way now, does not make sense with respect to the environment.

Actually, there is also 3th fighter - modern and redesigned combustion system as diesel or gasoline or even CNG which is interesting too. Again, it depends how the fuel is produced and synthesized. There has been done also big effort which is recently accelerated due to pushing down the emission limits.

Back to battery car vs fuel cell car. Even though my research field is fuel cell technology I admit that there is no reason to use sophisticated system as FC if you want to cross distance 10-15 km each day (work-shop-home triangle). Small electric car can do good job in this case. On the other hand you can go also by bus or by bicycle, which is definitely the best solution with regard to environment.

In case of this small electric car it is necessary to produce electricity by "green way" without burning coal or natural gas otherwise use CNG will be more effective and environment friendly for sure.

Electric car use battery for storage where the ratio:

ratio = (electrons released)/(protons in the system)

is always lower than in case fuel cell where this ratio for hydrogen is 1 = 2 protons/ 2 electrons. From this point of view, fuel cell car will be always more powerful. It will enable to cross longer distance and in addition it will produce heat in winter without loss of range. However, it depends how the hydrogen is stored. If we store hydrogen in metal-hydrides or even in heavy steel cylinders the above-mentioned ratio is decreasing. Lots of efforts have done in case of hydrogen storage and more efforts has to be done. I think that this ratio (electrons released)/(protons in the system) will be higher for FC car in the end especially for longer range of distances.

I think we will needs both technologies in near future and for longer distances the FC will be winner.

(I am sorry for longer text but it is interesting topic and thanks for question.)

Thanks alot @ Md. Washim Akram , but i've read these article and I couldn't get my answer.

The equation you put in your question doesn't match the stoichiometry of the reaction: formally, you are inserting CHCl into your Coronene/Nanographene slab, not CH2Cl.

The formula that Arezou Zarei brought up is the atomization enthalpy (=decomposition into single atoms), not the formation energy. The latter is defined as the energy required to form the compound from the most stable modification of its elements (i.e. graphite, H2 and Cl2), so choose what you actually want.

If you want the formation energy: Since calculating an actual graphite crystal (=periodic boundary conditions) is probably precisely the thing you want to avoid, I would decompose the reaction as follows:

2Coronene(unfunc) + C2H2Cl2 -> 2Coronene(func.)

All those are close-shell molecules that DFT can handle pretty well with a strong functional. The formation enthalpies of both educts can easily be googled.

The reaction energy ER can be calculated both from the absolute DFT energies Eabs as well as the formation energiesEF:

ER=2Eabs(Corfunc)-2Eabs(Corunfunc)-Eabs(C2H2Cl2)=2Ef(Corfunc)-2Ef(Corunfunc)-Ef(C2H2Cl2)

Now all you need to do is calculated the three Eabs values, get the Ef values of your educts from the literature and calculate Ef(C2H2Cl2).

Dear Miguel, you cannot assume a constant value of UA. The heat exchanger area A is fixed but the global heat transfer coefficient U depends of the properties of both flows: density, viscosity, mass flow rate, temperatures and, maybe the most important, the phase of the fluid. In off-design coditions, U must be calculated for each different condition.

I suggest to see the Matlab section where users share functions and applications. For sure, there is something similar to your ptoblem

Dear Mohammad, I developed many multi-carrier energy system models in MATLAB environment, if you are good in programming you may follow this way. Here you can find an example of my work on the topic (it is the only one published to date):

Hi,

Kindly refer bthe link:

Usually the difference between analytical and predicted values by simulation are not very large.

There has been a recent increase of interest in geothermal, specifically organic (and inorganic) Rankine cycle plants. Some have been built and more are underway. I have analyzed and tested several in North and South America and have contributed to the design of others. I provided testing and analysis for The Geysers plant in California, which uses the steam directly with barometric condensers. Recently, NOVEC 649 and 1230 have been declared the most "green friendly" refrigerants with respect to global warming potential. You can do significant modeling with Excel to evaluate various alternatives in design and working fluids. You can download a thermodynamic property Excel Add-In from my web site (http://www.dudleybenton.altervista.org/miscellaneous/NOVEC649.zip), as well as software to create a property Add-In for whatever else you might need. I attached a spreadsheet that solves a classic Rankine cycle as an example. You can also download a steam AddIn http://www.dudleybenton.altervista.org/miscellaneous/AllSteam102.zip

a few years back, we did some work on biomass using energy systems model. Project details can be found under https://www.psi.ch/en/eem/projects/chp-plant-swarm

Thank you all for your insightful comments.

There are several books of design of experiments where several common routines of sensetivity analysis are implemented in MatLAB

Dear Olusola,

As an advise you have to concentrate your search on the professors and institutions who make research and interested in your research experience.

In addition you have to prepare your C.V. reflecting your experience and your credentials not only in the PhD but also in the Msc and Bsc. Your performance in these earlier stages is also very important to get a post doctoral position.

You can access at first ask in Canada, USA, Australia, Europe and Japan.

Best wishes

I think the minimization you apply is force field based and doesn't seem to have meaningful parameters for the elements and geometry of your compound. You could try, altough demanding, a DFT based geometry optimization.

Hello Dear Mohammed ,

according to my information, the electricity market depends on the country you are in and each country has its own market

You can determine your question, which country do you mean? Or you mean in general

Best Regards

Lumped Analysis is applicable in the cases in which Bi number is less than 0.1. Bi is the convective heat transfer resistivity to conduction heat transfer Resistivity. in PCMs, phase change occurs which has a high convective heat transfer coefficient, and to use lumped analysis the thermal conductivity of the material must be very high.

Dear sir

I have many papers in optimization. Please explain more about your problems

Dear Mohammad

The total entropy generation of any system can be represented by two terms: thermal entropy generation (depends on the temperature difference) and frictional entropy generation (depends on the pressure drop). In some systems, the thermal entropy generation is dominant and in some cases vice versa. Compared with the entropy generation of the original design before optimization, it can be determined whether the improved design is better or worse. The design approaches the ideal state whenever the total entropy generation is as low as possible.

I agree with all the above comments. One more significant reason is you have to trace any changes in your battery constitutes after long period of charging/discharging cycles not only to confirm the long-term stability of your material or to trace any structural changes but also to trace if any hazardous components come out

As we move toward 100% non fossil energy we create a new problem. Will renewable energy have enough energy from day to day to power the energy needs of that day and the next day and the next day? In Texas several days of cloudy nearly calm weather in February create an energy shortage problem that is surprisingly worse than meeting summer loads. You can see some of the hourly data in this file I have posted which has links to the data https://egpreston.com/storage.pdf What is needed is long term low loss low cost energy storage but it does not yet exist. Some nuclear energy can bridge the gaps in renewable energy shortages.