Questions tagged [solar-energy]
Use for questions about non-photovoltaic solar energy applications, such as passive solar heating or concentrated solar thermal power. For PV applications, use the photovoltaics tag instead.
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24 views
Find the irrigation pumping rate (mass flow rate of a pump) versus time
Here is what we are given. Time ranges from 0 to 10 hours, with t=5 being solar noon. $\dot Q = 90Asin(\pi t/10)$ Watts, where A is the solar collector area in square meters and t is the time after ...
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16 views
Alternative materials for reflectors in solar concentrating systems
Other than the usual silvered mirrors, that are expensive to form into parabolas, what can be used as an effective reflector in parabolic troughs/dishes. I saw a few people tried using Mylar and Al-...
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1answer
31 views
Mirror specification used in Solar Fresnel Collector systems
Im designing a Linear Fresnel collector system, and wanted to know what type of mirrors would be suitable for use as the reflectors. Thickness, type, coating etc. I couldnt find a manufacturer of ''...
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1answer
29 views
Use of Cast Acrylic sheets as glazing in a Flat Plate Collector for domestic water heating
I am designing a FPC for heating water. I was wondering about the feasibility of replacing the usual Low-iron tempered glass with Cast Acrylic sheets [owing to non-availability of the former where Im ...
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2answers
27 views
Are cameras' CCDs just elaborate tiny solar cells?
While watching How It's Made episode on CCDs, this just springed to my mind... I always though of CCDs as of some kind of alien technology. Only now I realized that it's just an array of silica ...
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1answer
25 views
explaining ohmic loss and understanding inverter efficiency curve
I'm trying to understand an efficiency curve from PVsyst, using this documentation
However, I'm not sure what this sentence means:
This production is penalized by an ohmic loss$^1$ of the internal ...
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1answer
28 views
Explanation for photovoltaic circuit
My background is in Environmental Science, although I have recently been taught in the basics for energy engineering especially for solar panels.
I'm currently using PVsyst to build solar panels on a ...
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0answers
24 views
How does this one-contact solar cell work?
I am unable to grasp how this only-rear-contact solar cell works. From what I understand the solar cell produces electricity by making the top and bottom side of solar cell complementing each other (...
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2answers
38 views
Which kind of thermal oil is used in solar thermal power plants and how are they produced?
I'm currently researching some mechanisms for a simulation game, which also covers several electrical power plant options. As part of this, I'm currently looking at a solar thermal power plant, which ...
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2answers
55 views
Correct wind Weibull distribution for wind+solar system
I'm trying to forecast the peak power output for a wind + solar system. The solar output as a function of time of day and month can be forecasted easily. I also have the historical wind speed for a ...
2
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0answers
30 views
Internal Tent Temperature
Here is the problem I am working on:
"Consider a perfectly sealed polygonal tent with the sun directly overhead. The solar irradiance of a surface 90° to the sun’s rays is 1,000 W/m2. However, ...
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1answer
33 views
Capacity credit vs capacity factor
What is the difference between capacity factor and capacity credit? I know that capacity factor = annual generation / (installed capacity * 8760) but I don't understand how capacity credit is ...
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0answers
19 views
For a given surface area of sunshine are the latest solar panels more or less efficient than a Stirling engine?
I was wondering if the efficiency of current solar panels are better or worse than the current state of the art Stirling engines. I understand the former isn't a static variable and solar panels are ...
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0answers
19 views
Adding a black plastic layer to increase retained heat in compost
I have some invasive climbing weeds to break down into compost. I don't want to discard the biomass, but I do want to thoroughly kill all the weeds and ideally the seeds over a period of months.
The ...
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0answers
21 views
Can we use an open expansion tank in solar water heating system?
We all know that in an indirect (closed loop) hydronic system, an expansion tank is needed ,to deal with thermal expansion of the circulating water, that can be either open expansion or closed ...
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1answer
93 views
How do you calculate heat transfer due to solar radiation for a multi-layer wall given the incident solar radiation and wall specs?
Trying to come up with a MATLAB code for calculation of heat transfer due to incident radiation on a building's walls, would the solution involve using the conduction equation only? What would be the ...
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1answer
18 views
Would using activated carbon in a solar air collector help due to increased surface area?
Basically put a light coat of activated carbon on the collector, because surface area is so great, but I cant find info on its ability to collect solar energy, esp. compared to other materials. Im ...
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1answer
16 views
Joining the negative PV wires of 3 solar arrays for 3 MPPT controllers in an inverter?
My Inverter has 3 MPPT inputs. For some design simplifications (Involving ATS), i would like the three arrays to have separate PV+ but join the PV- wires together at a bus-bar and take the Inverter ...
2
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1answer
129 views
How do multiple enphase microinverters stay synced to the grid?
In a prior question it was established that any string or microinverter that is grid tied must put out sinusodial power. But there is also the task of being in sync with the grid. It seems from ...
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0answers
29 views
Solar power, Battery power to mains voltage
My question is what is the most efficient way to convert 48V D.C. to 220V A.C. Not the easiest or most cost efficient but the most efficient electrically?
Also if anyone has any cheats on the best ...
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0answers
74 views
Is it economical to use solar energy to manufacture solar panels?
Estimates of area needed to be covered by solar panels to power all of the US using only solar are about equal to a 100 mile by 100 mile tract of land. But solar panels have a lifespan of only a few ...
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1answer
54 views
What's the name of this parameter?
$ P_m=P_n*{G\frac1{G_{STC}}}*[1-\gamma*(T_c-25)]$
This equation is applied on sollar cells. $ P_m$ is the mean power produced in 15 minutes, $P_n$ is the nominal power [W], G is the insolation [W/m2]...
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0answers
129 views
Can a Tesla Powerwall 2 be rate limited?
Can a telsa powerwall 2 be rate limited (discharge/charge)?
I have access to realtime electricity rates (30 min update interval) and also access to 12 hour predicted look ahead. So I wish to limit ...
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1answer
29 views
Sonomotors, Sion: Can this electric car really charge up to 30km only from its solar cells?
Maybe you have heard about Sonomotors and its futuristic electric car, the Sion.
If not, here is the link to its website: https://sonomotors.com/
Anyway, the manufacturer claims that this car can ...
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1answer
76 views
What is the solar window (solar altitude angle range) of Bangalore? [closed]
What is the solar altitude at Bangalore at solar noon during summer solstice, March equinox, Winter solstice and September equinox? In other words, What is the solar window (solar altitude angle range)...
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1answer
70 views
How are solar panels at equator placed?
Are solar panels placed horizontally at the equators since the solar altitude (solar window) changes direction from north to south?
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1answer
38 views
What is the purpose of the isolated subpanel terminal of a solar inverter?
In a grid-connected (utility-interactive) battery-based PV system, what is the purpose of the 'Isolated Subpanel' terminal of the inverter?
EDIT: Found this descriptive image and hence answered the ...
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0answers
30 views
Hybrid Energy Monitoring Systems
I have been doing research on renewable energy systems and I must admit that I am a newbie in this specific area. I have noticed that stand-alone systems have their own specific monitoring system ...
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1answer
38 views
Electronics confusion
I want to build my own off-grid system but confused with what sizes (V, I) to get.
I want to run a 24v system powering 4.4kWh/day. I have 4 hours of usable sunlight a day and space for panels and ...
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1answer
43 views
Solar Thermal heat gain formula converted to CO2e and trees saved
We have invented a solar thermal heating system with interseasonal storage, recently patented. I want to display the trees saved and carbon offset on the control display based on temperatures coming ...
2
votes
5answers
286 views
Is it practical to make a solar furnace for small scale metal production?
Solar furnaces using mirrors to concentrate sunlight on a small area do not produce much power - perhaps 1kW per square metre of mirror - but can reach very high temperatures. From the earliest ...
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2answers
33 views
Did a RTC solar tracker need any photosensor?
I planned to do a solar tracker for my project and I am going to make a RTC solar tracker(actually still considering). So, do I still need photosensor like LDR for tracking the sun?
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2answers
206 views
Solving heat loss equation associated with solar trough concentrators
My project is about finding the efficiency of solar trough (cylindrical parabola) concentrator that will boil water in a pipe located at the focus (check picture please). In the process of doing so (...
3
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1answer
62 views
Is it better to heat a heat pump evaporator or the load directly?
I have a heat pump which moves heat from outside to inside. I also have a solar heating array that collects radiant heat from the sun. Given that my goal is to heat the inside (with minimal energy ...
3
votes
1answer
613 views
CUF v/s PLF of power plants
What is the difference between capacity use factor (CUF) of solar power plant and plant load factor (PLF) of coal based power plant? Can we compare both since they seem analogous?
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0answers
39 views
Charging a Li-po battery (battery output current)
I would like to design a buck converter to use a PV panel to charge a 11.1V 3000mAh 3S 30C Lipo battery.
I want to choose the minimum inductance for a CCM ($L=\dfrac{V_{out}T_s}{2I_{out}}$), what is ...
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2answers
169 views
Why not skip inverters and use solar power directly as dc?
To maximize efficiency and reduce cost I am contemplating using the power from solar cells directly as dc without conversion to ac. I plan to wire and connect the solar panels in series and parallel ...
2
votes
1answer
262 views
Design of Compound Elliptical Concentrator and Compound Parabolic Concentrator
What is the process in design a Compound Elliptical Concentrator and Compound Parabolic Concentrator if I wanted to achieve 100% optimal concentration ? Let's assume random numbers of: A light source ...
4
votes
2answers
739 views
Can solar panels absorb heat for energy?
Solar panels can absorb sunlight and use it for energy, but can they absorb the heat that is generated from their use and use the heat for energy?
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2answers
61 views
What material (preferably relatively inexpensive), can I use for absorber in a fresnel solar concentrator
I am thinking of building a prototype for a solar generator using a fresnel lens to concentrate sun rays to a relatively small area, for the purpose of harnessing the thermal energy.
The problem ...
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2answers
90 views
How to extract solar energy from a wall?
I have a vertical wall which faces the sun (North in my case as I am in New Zealand) and it gets hot in Summer.I should like to take some of that heat and transfer it into a nearby swimming pool as it ...
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1answer
84 views
Thermodynamics of an Arctic Greenhouse
QUESTION
For a business project, I'm looking into the viability of a greenhouse situated in Canada's far northern town of Iqaluit. The problem is how to mathematically simulate the internal air ...
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1answer
40 views
What tools to use for a solar powered backup? [closed]
Recently, we experienced complete outages for around 8 hours, due to construction on a nearby road. We have decided to install a backup battery and solar array to prevent this from happening in the ...
2
votes
1answer
44 views
What happens if current provided to mono phase motor is less than rated power
I have a 0.5 kW single-phase AC motor. What happens if the supply is 220 V but can't supply the full current needed? Will the motor torque be lower? Or will it be slower?
Will it be any ...
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1answer
297 views
Surface in the sun vs. surface in the shade [closed]
What is the difference in temperature between a surface in the sun as supposed to one in the shade and how is it calculated?
For instance:
What will the temperature be if a metal sheet lies in the ...
0
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1answer
52 views
Daylighting, how to improve coverage
I am doing this daylighting project for which we must bring the light far down into a bunker. I have found .
I have heard and read that the quantity of light that you bring in a cable decreases, 60% ...
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2answers
164 views
Did I wire these solar panels correctly?
recently I bought 3 solar panels rated at 5V 200 mA each. I want to use them to charge a 5V battery bank to charge a phone. Thinking about the proper way to put them, I thought i can connect all in ...
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7answers
5k views
What are the disadvantages of concentrated solar thermal power?
Concentrated solar power looks on the surface to be an excellent source of grid power. It's sustainable, has no obvious waste products to deal with either during construction or operation, and with ...
12
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4answers
3k views
Will more electricity be generated by using a lens to focus sunlight onto solar cells?
I have been wondering about this question for quite some time. Assuming an ideal case, the energy from photons hitting solar cells is converted into electric energy as described by the equation:
$RI^...
5
votes
1answer
216 views
Is it possible to modify a home gutter to absorb sufficient solar energy to melt ice?
This is related to the question Will dark gutters stay ice free better than light colored gutters? The current consensus seems to be that the mass of the gutters and limited light may make simply ...
