Read about solar | 41 Discussions | Page 1

  1. QuarkDecay

    I Direct polar radiation increases as...

    Does direct radiation increase as the zenith increases? I know the diffuse radiation increases as zenith does, but is it the same for direct Also is it right to say that when diffuse radiation increase, the direct should decrease and vice versa? edit: My book says diffuse increases as we...
  2. D

    I Heat Energy Intercepted by the Earth

    I've recently been interested in how much energy the Earth intercepts from the Sun; the answer, unsurprisingly was an astronomical amount, measuring quite easily into the ZetaWatts. However, the maths that got me that answer got me thinking... you can use the same method to determine the amount...
  3. A

    B Convert solar radiation from Joule per cm square to Watt per meter^2?

    I have solar radiation data in the units of Joule per cm^2 (joule per square centimeter) measured hourly. I want to use this data in evapotranspiratin calculation which requires radiation units as Watt per meter squared. How can I do this conversion?
  4. J

    PV system with an array of 1500 watts

    Hello all, I am in deep water here based on my very fundamental understanding of physics generally and solar design specifically. I am 83 years, homeless, and have access to land with one building, wood heat, non-potable site water, and nothing else. I want to make a PV system with an array...
  5. QuarkDecay

    I Solar Radiation/Eccentricity

    I have two questions (1) If we have two areas, for example one in America and the other on Asia, both with the same latitude φ, which one of the areas will receive more Solar Radiation? Or will it be the same? (2) If Earth's eccentricity graph for the past 750k years is this...
  6. T

    B Why does the sun affect radio wave propagation?

    I noticed HF radio waves travel farther and easier when the sun is out rather then during the night. Why?
  7. J

    I Calculating the incidence angle of the Sun

    Hi all, I have some difficulties understanding a formula for calculating the incidence angle for incoming solar radiation on a sloping surface. I found that: angle of incidence calculated as cos(j) = sin((pi/2)-surface slope)*sin(altitude angle) + cos((pi/2)-surface slope)*cos(altitude...
  8. S

    Optical Fresnel lens concentrator DIY

    Just running an idea for a diy fresnel lens past .. [ In the context that parabolic mirrors have been created by rotating a liquid ] The volume left above the parabola is also parabolic, so ...if that volume is used as a mold for casting it should form a reasonable solid lens, at least for...
  9. N

    My Plug And Play Solar Energy System

    Hi everyone, i'd like to share my packaged (plug and play) solar system project that I assembled at home. I used mostly standard parts such as a charge controller, inverter, 12 Volt UPS battery, and a pair of NEMA 5-15 R power outlets. I built the automatic transfer switch and battery...
  10. M

    Portable Energy Generator for off-Grid Villages

    I am a 3rd year integrated Engineering Student. For our 3rd year project we decided to make a portable generator to power laptops that were previously donated to an isolated off grid village in Nepal (for educational purposes). The laptops are currently sitting in rice bags and not being used...
  11. U

    Somewhat Complicated Thermal Problem

    Problem Description: I have a solar panel of some surface area, material, and thickness mounted to an enclosure. The panel is isolated from the enclosure at some distance with a multitude of materials (air, insulation, plastic, metal) between the back surface of the panel and interior volume...
  12. J

    How much energy is stored in compressed air?

    Hi all, My name is Jesse and I love renewable energy and finding ways of beating coal. Right now Solar Photovoltaic energy competes with coal in sunny areas during the day, but at night, you need to store the energy from solar and it's not worth it due to the cost of storage mechanisms (might...
  13. J

    I Calculation of daily solar insolation

    Hi all, I'm trying to calculate the daily solar insolation (integrated solar irradiances from sunrise to sunset) for a given location and day of the year. For latitude 43.2° and April 15th, I get: H0 = (solar constant * scale factor for intra annual variation of sun-earth distance * 86400...
  14. J

    I Calculation of the hour angle of the Sun

    Hi all, According to the sunrise equation, the hour angle of the sun at sunset is: cos H = -tan(a)tan(d) where H = the hour angle, a = latitude and d = solar declination angle. This equation says that H at sunset = -H at sunrise. Now, I have a few questions concerning that: 1) I was...
  15. J

    Making a solar powered battery with AC power socket

    It's mid summer and I think I need a project to keep busy. What better than a solar project? Problem is, I've never built a solar circuit before, let alone a battery charger. Ideally, I would like to build the equivalent of a solar powered generator. I know there's no way I'm getting as much...
  16. S

    I Horizontal to tilted beam radiation

    Hello, the name's Mike and I'm a newbie here, I have a question pertaining to solar angles required to calculate a solar panel's hourly generation over one year. Total solar irradiance on a tilted surface equals the sum of the direct, diffuse and reflected component. In my case, reflection is...
  17. Tianluo_Qi

    A Some questions about the PFSS model on IMF

    Hey guys, I am a Chinese student who is now reading the doctoral dissertation written by Mr. Heoksema, Structure and Evolution of the Large-Scale Solar and Heliospheric Magnetic Fields, for the preparation of my bachelor thesis. But some puzzles arise while reading the mathematic development of...
  18. SeaDawg

    Need help for project plans (Solar and Wind Generator)

    Hi, I'm trying to build an auto-sufficient station, this is my "blueprint" for mounting everything together : https://goo.gl/photos/4KLmhUc9EDccMPkYA and I would like to know if it was possible to calculate the voltage and intensity entering the Charge Controller without measuring it, if...
  19. B

    Confused with the relationship between Volts, Current, and Power

    Homework Statement For an engineering assessment (first year with no electrical background), we are using a solar panel to power an element for a distillation system. we have calculated our heat energy output requirement that we need from our heating element as being 800 J/s. For simplicity we...
  20. M

    I Sizing a Solar Array To Boil Water

    Hello, I am having a hard time deciding the size of a solar array to boil water for a school project. Before putting any thought into the subject I simply thought that I would just take the wattage of the panels and add them up since they are added in both series or parallel and then select an...
  21. W

    I Thermodynamic cycle of a solar cell

    Mechanical Engineering Undergrad here: So this didn't seem explicitly like a homework question, but I was wondering how to describe a solar cell in terms of thermodynamics. If I had to model it with the first law of thermodynamics, I would consider it a simple loop of heat/work exchange...
  22. Stavale8099

    Solar power, battery charging, and inverters

    Hello, I'm trying to teach myself ....still learning...but I'm stumbling. I have a 15W solar panel whose output is 5V and 2.1A. I wish to charge a 12V battery (98Wh/8800mAh), but am unsure how to do this calculation as approximate time it would take (Assume sunny days - I know it's an...
  23. marellasunny

    500 kg Solar CSP reflector dish mechanism problem

    I am currently re-fabricating solar concentrator dishes to allow for automatic tracking of the sun during the day and month. The industry term for these dishes is 'CSP' (Concentrated Solar Power). Task at hand: The CSP parabolic dishes are currently manually adjusted to the position of the sun...
  24. J

    Solar Energy Conversion at Night

    This is a fun thought experiment; Why not have space based mirrors to reflect light down to earth at night to make solar do a little extra generating! The cost of solar is coming down and the cost of lifting things into orbit is coming down, so why not. Plus gold is very reflective, light...
  25. pug

    Can a capacitor start a toy car?

    Hi, I am trying to build a solar powered toy car. And no its not for my son, its for my own curiosity. The problem I am having is that...while the solar panel is sufficient to rapidly turn the (4) micromotors 6 inches away from a lightbulb it isn't sufficient to even turn the wheels when I put...
  26. C

    Capacitor charging above solar cell voltage?

    This has been confusing me a lot lately. I built a type of battery derived from a solar cell that outputs a constant voltage of 0.5 Volts. My original plan was to work out a method to boost this voltage to around 1V to power a joule thief and light an LED using a capacitor charged by the cell...
  27. Jeffb47

    Converting torque to electricity

    We have a solar tracking device that uses phase change of paraffin wax when heated inside a solar receiver. With a helical slot in a torque tube we can translate the expansion into rotational motion. We use this rotation to point solar panels at the sun, thus generating more electricity. Look...
  28. lasisdabomb

    B Cotton Insulation vs Glad Wrap Bag for solar water heater?

    Hello Physics Forum. I have to complete a solar water heater project for school and choosing between what would be better for the insulation of a tin reservoir. I'm leaning towards the glad wrap bag because it will let more light hit our reservoir. However it will be a quite windy day and cotton...
  29. S

    Current limit through solar cell (forward bias)

    How much current can be forced through a photovoltaic (solar) cell before its performance starts to deteriorate? In certain accelerated lifetime testing 1.25xIsc is forced through a solar module while it sits inside a chamber (no incident light). Is there a theoretical limit to the amount of...
  30. R

    Space Travel to mars

    So off to Mars we go. But really how are we going to get there? The most expensive part of space travel is overcoming atmosphere. So you could say the biggest obstacle of space travel is Earth travel. It takes virtually no energy to cross space but it takes massive amounts to get into space...
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