Solar Energy

Solar Energy

  • Charles Yousif added an answer:
    Where can I find draw-off temperature profiles adapted to standard ISO 9459-2 ?

    The standard ISO 9459-2 is used to determine the long-term performance prediction of solar domestic water heaters. At the end of each test day, temperature measurements are made of water being drawn off and water entering the storage tank. Functions f and g are obtained.

    Charles Yousif · University of Malta

    Good luck

    Charles

  • Parviz Parvin added an answer:
    How good is Coumarin 30 dye for solar cell applications?

    How good is Coumarin 30 dye?

    Parviz Parvin · Amirkabir University of Technology

    High UV absorption ---> the solar UV radiation imparts  energy conversion ---> higher efficiency for solar cell

  • Louis BOISGIBAULT added an answer:
    Where can I access trend data on solar LCOE for Europe?

    I am looking for data on solar levelized cost of energy. I have US data. I am looking for Europe from 2009-2014. Is there anything available on the public domain? Most of the IEA/IRENA reports seem to be reporting for just one year or two. I am looking for trend data.

    Louis BOISGIBAULT · Université Paris-Sorbonne - Paris IV

    Dear Swarnalakshmi,

    You can find some tend data on PV LCOE with the European Photovoltaic Industry Association. It is based in Brussels. 

    http://www.epia.org/home/

    Regard

    Louis

  • Dazhi Yang added an answer:
    What is the minimum distance required for MET stations installation?

    I am planning to work with consultants to install met stations for solar resource assessment throughout the USA. How do you come up with a maximum inter station distance below which the measurement is redundant? Would the semi-variogram approach help? Is there a model/publication for the related problem? How do you take topography and other effects into consideration in deciding the distance? Would the distance along the longitude be more important?

    Best,

    Alemu

    Dazhi Yang · Agency for Science, Technology and Research (A*STAR)

    Hi Alemu,

    There are many ways to determine the interstation distance, depending on different applications (resource assessment vs forecasting). I mentioned this in details in my thesis (see chap 8). For start, you can look at several publications (see below). 

    Although there are only a few papers on monitoring network design in solar engineering, rich literature is available in statistics. There are two classes of methods, namely, entropy-based designs and kriging-based designs. Nevertheless, those statistical methods are very general; you have to be careful when apply them to solar engineering applications. Properties such as stationarity and normality need to be tested before applying the methods. In addition, solar engineering knowledge such as de-correlation distance (search for R. Perez paper for a start) and upscaling (see J. Kleissl's work for example) methods are very useful in design as well. 

    best

    dazhi

  • Heinrich Morf added an answer:
    Does anybody know if there is a common method for the clustering of the days according to the Clearness Index values (or any other weather parameter)?

    In the literature I found different Clearness Index thresholds for clustering days in different classes without any explanation about the method of choice.

    Furthermore, do you know if there is any other suggested method for clustering the days into different types: "Clear", "Partially Cloudy", "Cloudy"?

    Any references?

    Heinrich Morf · None

    There are possibilities to generate synthetic sequences of of sunshine, cloud cover, and solar irradiance as a function of time. For forecasting purposes one may then classify the values in the sequences.

    For example,

    Morf (2014) generates Markov chains for sunshine and cloud cover to forecast sunshine, cloud cover, and solar irradiance over varying time horizon and area.

  • Tahmineh Mahmoudi added an answer:
    How much is the carrier mobility of PCBM in polymer hybrid solar cells?

    I would like to know the carrier mobility of PCBM in polymer hybrid solar cells.

    Tahmineh Mahmoudi · Chonbuk National University

    Dear Maria

    Thank you very much.

    I have been working to incorporate hole transfer material as a third component with higher carrier mobility. 

  • Özgür Yildiz added an answer:
    How can I describe the relationship between certain characteristics of renewable energy projects and people's acceptability of the project?

    I am wondering is there any computable form describing the relationship between certain characteristics (e.g. the benefit) of renewable energy projects such as wind turbines and PV projects and people's acceptabiity of the projects. 

  • Shahnawaz Farhan Khahro added an answer:
    How are the values used in the equation to estimate the direct normal irradiation IDN at the earth's surface calculated?
    For further detail please see the attachment.
    Any help would be greatly appreciated.
    Shahnawaz Farhan Khahro · Alternative Energy

    Thank you Bailek Nadjem

  • K. Prakash Kumar added an answer:
    What are the possibilities of meeting the entire global energy requirements from renewable energy sources?

    Please discuss the possibilities, technologies required, changes required in energy utilisation methods and other related issues.

    OR is it foolish to think this way?

    K. Prakash Kumar · VIT University

    There are some studies initiated towards the question. And some are giving a positive results too. One can refer the link attached.But , yes, there are many hurdles. 

  • Macho Anani asked a question:
    If none of the Shockley and Queisser suppositions were necessarily true, how could we significantly improve their limit?

    The analysis of Shockley and Queisser relied on hypothesis that only one electron-hole was created per incoming photon, there is a thermal relaxation of the electron-hole pair energy in excess of the band gap and finally that the illumination process was under one sun.

  • Amin Bennouna added an answer:
    How can we encourage homeowners to adopt solar energy in rural areas?

    Cleaner forms of energy and their associated technology provide sustainable solutions to the environmental challenges.)

    Amin Bennouna · Cadi Ayyad University

    From 1999 to 2005, we sold about 10'000 solar home systems on a credit scheme.

    Mark penetration of SHS in rural depends on:

    1- the cost of energy to be substituted by solar,

    2- the appropriatness of the end-user financing scheme(s) 

    3- the efficiency of the company field presence.

    The detailed meaning of each of these 3 items has to be adapted to each specific budgets, population and region. 

    To avoid wrong ways of doing, there are a lot of lessons to learn from former experiences like Escom-Shell (S.A.), NoorWeb & Temasol (Morocco), Lotus (Nepal) and few others in SE Asia and Latin America. 

  • Giuseppe Marco Tina added an answer:
    Does Low-Concentrated Photovoltaic reduce payback period if comparing with conventional PV technologies?

    As I know, the amount of energy output from CPV usually high than conventional PV which give benefits to reduce Levelised Cost of Electricity (LCOE) especially with high-concentration photovoltaic. But for this question,  does CPV technologies can reduce payback period wtih Low Concentrated PV even though the capital cost a bit higher than conventional PV? 

    Giuseppe Marco Tina · University of Catania

    The evaluation of the real increase of yearly energy produced by a LCPV (Low concentration PV) requires a detailed model of the system, especially for the electrical aspects. The presence of an uneven radiation in an array wrongly connected, in fact, can nullify the advantages coming from the augmentation of the radiation, since the P−V characteristic of a PV string with bypass diodes under non-uniform irradiation contains multiple peaks. That means more local maximum points and therefore the optimum point of PV array is shifting far from the local maxima where the conventional controller is used to be operated. The global maxima is dependent on the array configuration and shading patterns. In order to overcome such a drawback, in the last decades, the efforts to improve PV generation systems have originated many solutions to the power reduction caused by mismatching in the PV modules. Among these, the use of Distributed Maximum Power Point Tracking (DMPPT) DC−DC converters could be a promising technique that allows the increase of efficiency and reliability of the whole system. Using this approach, the Maximum Power Point Tracking (MPPT) is calculated for each module of cells within the string, therefore the resulting efficiency of the distributed architecture results to be higher than that one of the conventional topology where the MPPT is calculated in the centralized inverter [1 - 3]. Of course, using distributed PV architectures leads to higher costs compared to conventional approaches. Therefore, a trade−off between costs and advantages in terms of output power of the PV plants should be investigated for each application taken under consideration. In [4] authors affirm that, under partially shaded and non−uniform solar radiation conditions, the use of distributed power electronics can recover between 10% and 30% of annual performance loss or more depending on the system configuration and type of used devices. Of course, when the impact, in terms of duration and extension, of the aforementioned negative phenomena is limited, the use of distributed power electronics does not appear economic, but in case of LCPVs are used, it is expected that a DMPPT could lead to great advantages.
    [1] Olalla C, Clement D, Rodriguez M, Maksimovic D. Architectures and Control of Submodule Integrated DC–DC Converters for Photovoltaic Applications. IEEE Transactions on Power Electronics 2013, 28 (6), pp. 2980-2997, DOI: 10.1109/TPEL.2012.2219073.
    [2] Pulvirenti F, La Scala A, Ragonese D, D’Souza K, Tina GM, Pennisi S. 4-Phase Interleaved Boost Converter with IC Controller for Distributed Photovoltaic Systems. IEEE Transactions on Circuits and Systems-part I 2013, 60 (1)1, pp. 3090–3102, DOI: 10.1109/TCSI.2013.2256235.
    [3] Grasso AD, Pennisi S, Ragusa M, Tina GM, Ventura C. Performance evaluation of a multistring PV module with distributed DC-DC converters. submitted to IET, July 2014.
    [4] Deline C, Marion B, Granata J, Gonzalez S. A performance and economic analysis of distributed power electronics in photovoltaic systems. Technical Report NREL/TP – 5200 – 50003, 2011.

  • Daniel Hinchliffe added an answer:
    Is there any kind of sustainability/recyclability label or certification for solar panels?

    i.e. legitimate labels which show that life cycle effects have been taken into account in the design of the solar panel? Not just a marketing ploy or greenwashing.

    Daniel Hinchliffe · Bundesanstalt für Materialforschung und -prüfung

    Ok great, thanks for these answers, I will take a look into each of the points for further information and post back here if anything else comes up.

  • Andebet Gedamu added an answer:
    What does a large difference between the open circuit potential in the dark and the illumination conditions imply?

    Application with solar cells

    Andebet Gedamu · National Taiwan University of Science and Technology

    This might be useful http://jes.ecsdl.org/content/155/5/F91

  • Jethro Betcke added an answer:
    What are the indirect disadvantages of using Solar Energy Technology?

    Normally Solar energy is Eco-friendly, how ever the ingredients required to prepare the process of solar collection is complicated and requires different forms of raw materials or processed materials. Is there any known hazard or disadvantages of such products?

    Jethro Betcke · Carl von Ossietzky Universität Oldenburg

    @Hengky:

    "Green 2015" does not really help readers to find the original source. Since we are not writing a scientific article here, a simple link would suffice. Like this:

    http://www.conserve-energy-future.com/Disadvantages_SolarEnergy.php

    Regarding the list: I find it a bit of a strange mixture:

    Points 1,2 , 5 and 6 are formulated as disadvantages for some potential investors. 3 and 4 are formulated as general problems. Points 5 and 6 are only relevant if your aim is to be self-sufficient in your electricity production.

    I already addressed point 3.

    Regarding point 4. I find it a bit weird to see solar cell inefficiency as a problem on its own. Sunlight comes for free, and does not pollute. Efficiency of course does influence the cost per kWh and the pollution per kWh. However, these points are already in the list, so point 4  seems to be added just to fluff up the list.

    Point 1, 5 and 6 could of course be generalised.

    1) Solar power was very expensive just a few years ago. But cost have come down tremendously and are still falling.

    5) Without cheap storage, the variability of the solar resource limits the amount of solar power that can be integrated into the grid. However, more is possible than most people expect intuitively. In their report, "the power of transformation" [1], the IEA comes to the conclusion that with existing technology 45% of solar and wind power can be integrated into the grid at acceptable cost.

    6) The area needed to provide all the earth's energy needs with solar power is only a minute fraction of the earth surface. So there is not really a problem here.

    [1] http://www.iea.org/newsroomandevents/pressreleases/2014/february/any-country-can-reach-high-shares-of-wind-solar-power-cost-effectively-study-shows.html

    http://www.iea.org/bookshop/465-The_Power_of_Transformation

    P.S. Please, don't be offended by my Dutch directness. This is just one of those cultural differences.

  • E. Vagos Hadjimichael added an answer:
    Can anybody tell me most optimization technique in solar cell for getting higher efficiency?

    Can anybody tell me most optimization technique in solar cell for getting higher efficiency?

    E. Vagos Hadjimichael · Fairfield University

    Orientation of solar cells: south-southwest

    Tilt with horizontal: about 23-25 degrees

    Use a sun tracker

    No shade from trees

    Performance decreases with higher module temperature.

  • Omar Z. Sharaf added an answer:
    Can a solar panel generate electricity from a hot body which radiates heat?

    Solar panels convert solar energy into electricity. but the solar energy incident on solar panels is in form of heat . So, is it possible for a solar panel to generate electricity if we supply heat source?

    Omar Z. Sharaf · American University of Sharjah

    Directly converting thermal energy (whether conducted through radiation, convection, or conduction) is done using thermophotovoltaics, thermoelectric generators, thermionic generators, and magnetohydrodynamics generators.

    Alternatively, it is possible to use upconversion technologies to convert a stream of low energy photons (e.g., IR) into a stream of higher energy photons (e.g., visible).

    Most of these technologies are; however, still under R&D.

  • K. V Sharma added an answer:
    How to calculate monthly average daily extraterrestrial radiation on a horizontal surface? (please see the attached file and guide me)
    Please see the attachment for detail
    K. V Sharma · Universiti Teknologi PETRONAS

    can you send me the data that you have?

  • Rafael Sánchez Sánchez added an answer:
    What is panchromatic absorption?

    When can we say that it shows panchromatic absorption?

    Rafael Sánchez Sánchez · Universitat Jaume I

    Panchromaticity is an optical property of certain materials that are able to absorb light in the entire visible spectral region.

  • Pavel Vorobiev added an answer:
    What would be an efficient dc motor which can be used for solar tracking system?

    I need to rotate a solar panel of 1kg weight to both clockwise and anti clockwise direction.

    Pavel Vorobiev · Centro de Investigacion en Materiales Avanzados, S.C.

    Just adding some practical examples to the excellent information already provided by others. There is this little economic gear motor from Dayton, it costs 70 dollars and it's 0.5 RPM, which is already very slow, but of course you can slow it down more by using PWM feeded through an H-bridge from a microcontroller.

    I have driven a 700kg tracking array with it (through additional bigger gearbox, of course), my guess is that it would successfully drive up to maybe 20kg by itself, maybe even more. Here is the granger link to it:

    http://www.grainger.com/product/DAYTON-DC-Gearmotor-2L003?s_pp=false&picUrl=//static.grainger.com/rp/s/is/image/Grainger/2L003_AS01?$smthumb$

    Another great motor are those used in wipers mechanism, so you can buy one of those in any automobile-related shop.

  • Ken Schatten added an answer:
    Where I can find good sunspots and cosmic rays data in the equator area ?

    I'm from Indonesia and need good sunspots and cosmic rays data in equator area for my thesis. Please help me, where I can find that data ?

    Ken Schatten · ai-solutions

    To me, the best places for repositories of such data is NOAA's SWPC space weather prediction center. A lot of data is on the web from their repositories...SWPC used to be called SEL space environment lab... The detailed data may be at the spidr web site cited, but the overall NOAA sites include this and others.. Not sure about equatorial

    data, but there are , as mentioned a number of cosmic ray data, as well as geomagnetic activity (being monitored by a number of stations around the world)..good luck,

  • Khalid Kamal added an answer:
    What instruments and software are required for Organic Solar Cell R&D ?

    What instruments and software are required for Organic Solar Cell R&D project, how can I initiate it ? 

    Which software will be best for its simulation and does someone have old code which they have published that they may provide or suggest me ?

    Thanks

    Khalid Kamal · University of Delhi

    which simulator should I use for solar ?

    I used earlier Geant which is used in physics simulation I also have been used Matlab.

    which one is The Best  ?

  • Yang Li asked a question:
    How can we calculate the mouthly average of solar zenith angle in Jule in London(51.518°N, 0.128°W)?

    Such as in Jule in London(51.518°N, 0.128°W)? (daytime)

  • Elangovan Sundaram added an answer:
    What is the best method for tracking the sun position, is-it by solar position calculation along the day of the year or by other method?

    In solar energy application, often we should know the sun position at each instant. With the sun position calculation, I think we can establish a database for this purpose. Then we can use-it for tracking the sun using for example any circuit with an embedded PIC. Other methods were used. Which is the best ?

    Elangovan Sundaram · ALL INDIA RADIO

    A  simple servo mechanism with dual sensor mounted in a  perpendicular plane  for Azimuth and elevation with micro controller based DC drive  will solve the problem.

    simple polar actuator will  give a part solution where you have to optimize in regular interval (Probably weekly once)

  • Khursheed Ahmad added an answer:
    What's the major challenge of perovskite solar cells?
    It is such a hot topic these days. What's the major challenge in this field? Is it really going to be a mainstream technology?
    Khursheed Ahmad · Chonbuk National University

    Organo metal halide perovskite are the best to date in photovoltaic devices, but why could oxide perovskites not in the same manner?e.g. CaTiO3?

  • Yasser E. Abu Eldahaba added an answer:
    Does anyone have failure rates figures for solar components?

    I'm looking for failure rates (λ) for the following:

    PV panels (I have already found a study giving a figure of 2.96 failures/10^6 hours

    VRLA Batteries

    PV inverters (preferably off-grid)

    PV charge controllers

    Yasser E. Abu Eldahaba · Ain Shams University

    Please find a complete Review of Failures of Photovoltaic Modules  in 

    http://engineering.case.edu/centers/sdle/sites/engineering.case.edu.centers.sdle/files/iea-pvps_t13-01_2014_review_of_failures_of_photovoltaic_modules_final.pdf

  • Ravi kant Ravi added an answer:
    What should be the minimum distance between glass plate and heater in a solar air heater ?

    In the case of solar air heater for use in artificial simulators, what should be the minimum distance between electric heater and the glass cover?

    Ravi kant Ravi · Indian Institute of Technology Roorkee

    thanks to all....

  • Farzaneh Arabpour added an answer:
    What module do I need if I want to simulate organic solar cell with COMSOL?

    I want to simulate organic solar cell with COMSOL. Because I am new to this software, I would love to know what modules besides the software I need if I want to do this work. 

    Farzaneh Arabpour · Tarbiat Modares University

    Dear Li

    as mentioned, it depends on the type of simulation. If you want to simulate optical aspects of this structure, Comsol is ok, while I believe software are not able to show details. But, for electrical simulation(device photovoltaic performance) Silvaco can be useful. 

  • Seoyeon Cho added an answer:
    How can one make perovskite a solar cell?

    I made a perovskite solar cell. But it is the wrong cell. So I checked my cells with SEM, XRD. Sem image show bl-TiO2(50nm), TiO2 paste(250nm). XRD show (110),(220) peak.

    I use TiO2 Paste DSL 18NR-T(dyesol), P3HT as Hole Transport Layer, Aluminium(70nm) as Electrode.

    I have no idea why this cell doesn't work. 

    Thank you for your help

    Seoyeon Cho · Inha University

    Thanks! Everybody

    I am going to experiment again

    'Cell is wrong' means that it is not working as 'Solar cell'

    For example Fill Factor pass over 100%

  • Olaf Schilgen added an answer:
    Is it possible to save renewable energy, if so how and what is the loss rate (per time unit)?

    Renewable energy is typically generated when it is not necessarily needed: solar power is produced when sky is clear mostly at noon, wind power is fluctuating and is highly dependent upon the weather conditions (in particular between 40° and 60° N as well as 40° and 60° S the weather conditions are highly dynamic, etc. The question is can this energy reasonably be stored, if so how and what is the rate of loss (because there is certainly some kind of loss).

    And any answer depends very much from the scale of the system you are planning.

    If you're talking about a "my home is my energy castle" solution, then you can forget "pumping water" as a solution, you will use batteries.

    If you are talking about an energy system for a country ... you will very much talk about a reasonable grid for sharing the (locally) fluctuating different sources of renewable energy in a bigger scale where the netto generation and also the netto use is much more stable and much more predictable.

    For example: Germany does not have a need for big storage solution for the next 10, 14 years with a ramp up of renewables share in electricity up to 40% to 2030. A better grid is sufficient ...

About Solar Energy

Energy transmitted from the sun in the form of electromagnetic radiation.

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