Questions tagged [solar-energy]

Form of renewable energy emitted by the Sun, coming in two flavours: photovoltaic and thermal. The former, especially, relates closely to electrical engineering since it is traditionally harnessed through semiconductor devices and converted to AC in order to feed the electric grid or individual users' homes.

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40
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2answers
4k views

What is the failure mode of a solar panel?

I have understood that solar panels don't last forever. Warranties are typically a couple dozen years, and you can expect your panel to last for perhaps twice the warranty period. But what does ...
25
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3answers
6k views

Why does inverter synchronization with the grid take 5 minutes?

We had some solar panels & an inverter installed recently. Every time the inverter is turned on (after maintenance or with the first light of the day) it has to synchronize its generation phase ...
24
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5answers
4k views

Why are off grid solar setups only 12, 24, 48 VDC?

I am looking to produce 50kW for an off grid solar project. Ideally, I'd like to have a high voltage DC battery system with a high power battery inverter and charge controller. I have only found a ...
8
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4answers
4k views

Purpose of using diode with solar panel

I have been working on a design based on solar power. While browsing through some circuits on the Internet I came across these designs below In these designs, why was a diode added between the solar ...
7
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0answers
224 views

Is the duck (curve) still a duck? [closed]

In 2013 the California Independent System Operator (CAISO) published this image, dubbed it "the duck curve", and took the internet by storm (or, at least the part of the internet that tracks trends in ...
5
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6answers
981 views

Can I use DC to drive underfloor heating wire?

I'm in the early phases of designing a new underfloor heating controller for retrofitting solar panels to locations with existing underfloor heating cables, which now take their power from the grid. ...
5
votes
1answer
105 views

Can a solar inverter be damaged if installed capacity is much larger than demand?

I had a dispute with my fellow. In his opinion, a power inverter can be damaged if the load is much lower (e.g 100W) than installed capacity (e.g. 10kW) of the solar system. I am of the opinion that ...
5
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3answers
402 views

Is it safe to run a PC fan with power low enough to stall it?

I have a "6V 4.5W" solar panel (Generic) and a 12V PC cooling fan (Evercool PWR-1225H12B) that consumes 450mA at 12V full speed. Running the fan directly from the solar panel in full sun works ...
4
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2answers
943 views

Solar powered mini fan

for a school project I have to do something that needs the environment to work, my plans are to make a solar powered mini fan, now my question. How can I make that the fan ( 6v dc motor) keeps working ...
4
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2answers
582 views

How does a residential grid-tied solar system work exactly?

Ok.. so I know how solar panels are connected to a combiner box & tied into a charge controller/inverter. I also know that the AC from the inverter must be in phase with the line/mains power. ...
3
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3answers
5k views

Do solar panels generate variable current or variable voltage?

Many solar panels are watt-rated. The generated power depends on lighting conditions, so either the current and/or voltage is variable. Which one is it?
3
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5answers
1k views

Diode type with lowest drop voltage [duplicate]

I make a small solar energy harvester. I'm searching for the type of diode with lowest drop voltage. Any suggestion for the type of diode for me ? Thank you
3
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4answers
488 views

Is there a minimum amount of electricity that can be fed back into the grid? [closed]

This is not fully related to electrical engineering, but I have been reading lately about Feed-in-Tariffs and solar energy production and I cannot find any information on the amount of energy that can ...
3
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3answers
565 views

How can microinverters be as efficient, or more, than power optimizers of solar arrays?

According to Wikipedia: solar panels produce voltages around 30 V. This is too low to be effectively converted into AC to feed to the power grid. To address this, panels are strung together in ...
3
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4answers
372 views

Maximum power point traking

I'm having trouble understanding maximum power point tracking. How can I track the Maximum Power point? How do I consider the effects of load on Voltage and Current while power point tracking? ...
3
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4answers
547 views

Best practice: Should I charge a battery while also pulling load?

I have an off-grid solar panel setup. The solar panels send current to an MPPT charge controller. The charge controller controls current to a lead acid battery. On these same battery terminals I have ...
3
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2answers
330 views

LT3652 Inductor Selection

First question here In my system, a LT3652 IC should drive a solar panel with these specifications: Voc = 9,94V Vp = 8,54V Vmp = 7,95V Isc = 0,90A Wp = 7,15W to charge a 3,7v Li-Ion battery at ...
3
votes
2answers
8k views

How could a solar panel drain my battery? [closed]

This question is in regards to a 100 Watt solar panel that is less than a year old. The solar panel was working fine but recently something happened. Now when I hook the solar panel up to my ...
3
votes
1answer
2k views

Switching between battery voltage and solar voltage to control load. in solar charger?

I designed a solar charge controller using arduino and MOSFET IRF9530. Main purpose was to charge 12V 7aH battery and then control the load. Here load is a solar ...
3
votes
1answer
3k views

Modeling a solar panel for simulations

I need to simulate a power conversion system (using SIMetrix/SIMPLIS) in which solar energy is captured by a solar panel, which is then connected to an inverter for supplying current to the grid. ...
3
votes
1answer
761 views

How do you calculate the hourly output, measured in kWh, of a 1 kw solar photovoltaic panel given hourly irradiation data in kj/m2?

I am working to build an economic model that includes hourly solar output for solar photovoltaic installations built at several different geographic locations. I have data on irradiation (Direct ...
3
votes
1answer
54 views

Can my solar inverter be significantly driving UP my power consumption or my meter counting excessive production as usage?

I've had a 1.5KWh PV solar system for 3 months now and as any new user I've been monitoring the power generation closely. I've wanted to correlate the power generation to my power usage so I've ...
3
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1answer
295 views

Different Wattage Solar Panels for Home [different Voltage/Ampere]

My current solar system for home 12V 100W polycrystalline Solar Panel. 12V 75Ah Lead Acid solar tubular Battery. PWM 12V 10A Solar Charge Controller. 12V Input and 200VA Output Inverter. Current ...
3
votes
1answer
5k views

12V battery is now 10.5V but still producing a lot of power

I'd appreciate if someone can advise and give me an idea about the condition of my battery and my overall set-up. I set-up off grid solar system about 2 years ago, for my parents in my hometown ...
3
votes
2answers
4k views

Grounding solar controller

I am wiring up the solar system in my van and I need help with claryfing some things up. I have a Phocos CA08-2.2 controller and in the manual one can read: Be aware that the positive terminals ...
2
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3answers
1k views

How does a maximum power point charge controller regulate the charging current, when it always draws the maximum current from the panel?

I want to understand exactly how an MPPT charge controller works and all I could find is this: An MPPT charger is a DC-DC transformer, that when it lowers the input voltage, it raises the output ...
2
votes
2answers
605 views

What are the ways to power 5V sensor using solar panels?

I have an outdoor sensor (which will have to work in the winter on Poland, however, we usually have temperature much over -10 Celsius degrees) which needs 5V. The sensor operates 24 hours per day ...
2
votes
2answers
279 views

What is the best way to limit voltage of a solar panel? [closed]

I am using a 6V 6W solar panel with the Particle Boron microcontroller with a battery pack. I want to ensure that the voltage supplied by the solar panel does not surpass 6.2V, as that is the max ...
2
votes
2answers
396 views

Charge lithium ion batteries at -30°C

I see here (Battery University) and here (Electrical Engineering StackExchange) some claims that it is indeed possible to charge lithium ion batteries at -30°C if you do so at a 0.02C rate, but I don'...
2
votes
3answers
103 views

Problem with a relay decoupling voltage

I made a simple circuit to alternate its output between two inputs: a photovoltaic panel and a 12V DC voltage source. The schematic: The step source represents the photovoltaic panel and the two ...
2
votes
2answers
118 views

Micro Watt Meter in Extreme Low Temperature [closed]

I'm using a solar panel in the Arctic and I want to measure the power it delivers to the associated sensors. Is there any recommendation on a watt meter for this environment? The temperature is ...
2
votes
1answer
291 views

Is there any technical/safety reason to ground off-grid solar?

Unlike this similar unanswered question I will keep this question here focused and specific. Imagine an off-grid solar system: panels, charge controller, battery, inverter, AC and DC appliances. ...
2
votes
3answers
2k views

Does a Buck-Boost Converter/PWM controller significantly reduce the energy you can get from solar panels?

As a heads up, I edited this question to make more sense based on what I have learned. I think this is okay since no one has answered the previous question yet. So I'm designing a solar system and ...
2
votes
2answers
398 views

5V 1A Solar panel only delivering low power

So I bought this 5V 1A solar panel that can be used e.g. to charge your smartphone accroding to the product description. When I measure the voltage using a multimeter I measured 6.9 V. A little bit ...
2
votes
3answers
793 views

Enable grid-tied solar array power output during grid outage

I am getting close to investing in a micro-inverter (Enphase M250) based grid-tie solar array for my home, but am concerned I won't be able to use the solar power during grid outages. I found a ...
2
votes
3answers
490 views

Efficiency of solar panel under warm-white LED light

I need to transfer power from ground level and from a normal 230 V outlet to up to a test jig which is at high potential. I need about 50-100 mW after all losses to power my circuit. Power is too low ...
2
votes
1answer
58 views

Why does shading a single PV panel in a series string reduce the current output of the whole string?

I would like to understand how shade on just one panel in a series string reduces the current output of the complete string.
2
votes
1answer
96 views

How to connect a photovoltaic to a heating element directly

I am trying to connect a photovoltaic panel directly to a heating element (coil) without using a battery or an inverter and switch it on or off by using a transistor or a thyristor. I am well aware ...
2
votes
2answers
70 views

How to calculate battery ratings for your solar panel?

If I want to choose a battery for my solar panel which is required to run a load of 5 kWh/day. Then I will be needing a battery with a rating of above 23 ampere hours since 5 kWh/220 V (since 220 V we ...
2
votes
2answers
153 views

How to partially drive a load with respective impact on my electricity meter?

I want to optimize the use of my photo-voltaic production by redirecting the remaining unused energy to electric heaters in winter, or something else in summer (given that fans are inductive loads and ...
2
votes
1answer
47 views

How does a solar cell its relative thermal coefficient “alpha” expressed in 1/K relate to %/K?

Some times I see the relative thermal coefficient of solar cells Isc (called "alpha" or α) written as 1/K, other times as %/K. ...
2
votes
1answer
289 views

Why Peukert's law is always ignored in battery(lead Acid) guides available on Internet?

I am doing battery calculations for off-grid solar panel. I don't get that why battery guides on Internet always ignore Peukert's Law for batteries of solar panel. I want to have good approximations ...
2
votes
2answers
100 views

Home solar system - COB LED Drive

Recently, I have installed an off-grid solar system - MPPT charge controller, batteries and solar panels. Overall the system provides a DC 12/24/36/48v power (60A Max). The main load I want to drive ...
2
votes
1answer
77 views

Storing solar panels in direct sun

What is the best way to store solar panels when not hooked to a charge controller in direct sun? I was thinking about hooking each panels pos and neg mc4 connectors to itself so it will not be ...
2
votes
2answers
334 views

Solar panel as day/night switch for a load

I'm using off-the-shelf components to power a buck/boost LED driver and charge a battery from a 6V solar panel. To power the LED driver from the battery at dusk only, would I have to use a MOSFET ...
2
votes
4answers
3k views

How do MPPT charge controllers curtail the power if the load is less than the solar generation?

I am trying to understand how MPPT charge controllers work when the load is less than the solar power generation. Let's assume an off-grid system with battery backup and no dump load. In my ...
2
votes
2answers
15k views

Am I supposed to ground the inverter or the battery? Or both? To vehicle chassis

I am setting up a solar system in a vehicle. I have 400W solar panels, a 12V battery bank, and a 2000W inverter. I've looked at the manuals and read online to figure out the wiring diagram below. ...
2
votes
2answers
251 views

Avoid current spike in buck converter

In image my model to simulate PV array & MPPT with buck converter . The result from this model have two problem: At t=T=1/f occur current spike in diode current and Vpv up above Voc. In battery , ...
2
votes
1answer
119 views

How much installed capacity of wind or pv would be required to match the output of a 4GW nuclear power plant

I am trying to understand the challenge of decarbonising the power grid, and the equivalence between different generation technologies. If a nuclear power plant has a capacity of 4GW and a capacity ...
2
votes
0answers
127 views

Calculating realistic solar cell output

This past summer I installed a couple of 12 volt 100 watt solar cells on the roof of my caravan. I was never naive enough to actually expect to get 100 watts out of them, but I've still been very ...

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