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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How can I transport sunlight (with UV, IR etc...) across space?

I currently have a tiny vertical farm which I am trying to make as energy efficient as possible. A big chunk of my power consumption comes from LED lights which are powered by solar panels/batteries, ...
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Solar bimetal/dilation power generator

What attempts are there been at converting on Earth's surface, night/day temperature differences, so that the dilation of a large bimetal is converted into mechanical work ? At small scale it would ...
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Solar power system, hybrid, 48 V & 24 V inverters in parallel

I am planning on getting an off-grid/hybrid power system for my house. We have a shortage of inverters in South Africa currently. Is it possible to have 2 inverters in parallel: one of them 48 V (5 ...
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Is Mostly-Passive Solar Desalination Possible in a Desert Climate?

It seems like it should be possible to have almost entirely passive (minimal moving parts or machinery) solar desalinization that would be ideal for desert countries bordering the ocean. e.g. Northern ...
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Combining lower & higher rated solar panels

I have a set of 6 panels 75W each @ 19.1V | 3.92A Another set of 4 panels 435W each @ 44V | 9.87A Now how to add these such as to optimize Watts to maximum? Plz see the attached calculations. Am i ...
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Need a solar powered mechanical motor? that moves a leaver up and down low force and little distance on day/night

I'm planning to use barrels full of water to make a drip watering system. I can make the water controls from a pretty easy toilet fill&flush valves and balance it so it needs a very light push on ...
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What materials to use indoors to absorb sunlight and store it as heat?

This is a very practical question; the underlying principles are, I imagine, extremely well-known. I'm buying a new place in the northern hemisphere (49° N) with lots of southern (or rather SES) ...
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how much energy is stored in a car under sun ? (car interior)

When a car is under the sun, the interior is hot. This is due to the interior, especially seats, which are black (or a dark color) so that they heat under sun light and restitute this heat to the air. ...
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Can a grid connected PV system deliver power backwards through the distribution transformer?

If there is no local load demand can a residential roof top grid connected PV system deliver power across distribution transformer [up to the higher voltage grid]? Suppose my grid connected solar pv ...
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Solar Thermal Collector to Boil Water (100 deg C)

Is it possible to build a Solar Thermal Collector that boils water to 100 deg C? I've seen a lot of Solar Thermal Collectors that claim to be able to boil water, but every example demonstration that I'...
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A shape that focuses light from the widest range of incidence angles into a smaller area

I remember reading about devices which were roughly hyperboloid in shape that had the property of focusing light from a much wider range of incidence angles than a parabollic antenna. I think they ...
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Can air currents be used to keep dust from settling on solar panels?

I've been trying to build products to start my own solar company. A common issue with solar panels is dust accumulation, which reduces the already low efficiency even further. I've been working on ...
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Best metal for solar energy collection in an evacuated tube solar water heater

I am building an evacuated tube array for a solar water heater and I am selecting the materials to use for the tubing and the collectors (the places connected to the tubing that help absorb the solar ...
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How large would a solar panel array need to be in order to supply all the world's energy?

This story from 2016 claims that all the world's energy needs could be supplied by covering 1% of the Sahara in solar PV panels. Was (is?) this true, and if not, how would you go about approximating ...
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Why are there no propane refrigerator air-conditioning units that run on solar heat?

I was thinking about how hot it was outside, when a thought came to me. There are propane refrigerators, so why not replace the propane as the heat source with solar heat and then change it from a ...
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Problem with relationship between shunt resistance and grain boundaries in a solar cell [closed]

Here is the correct answer from another stack website. The higher shunt resistance means that higher the polycrystalline lattice irregularity and many grain boundaries. This means higher current ...
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Why do monocrystalline solar cells have rounded/cropped edges?

What is the meaning of this croped part? Why do they crop it, rather than let it be full square?
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Why do solar cells need to be square-shaped?

There were circular solar cells 30 years ago. Why do we have square-shaped solar cells now? Why square? Furthermore, Why do monocrystalline solar cells have rounded/cropped edges?
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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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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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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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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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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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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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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 ...
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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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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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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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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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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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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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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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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 ...
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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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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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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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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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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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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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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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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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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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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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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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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 ...
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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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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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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 (...
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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 ...
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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?