Tag Archives: Monocrystalline solar panels

How Do Solar Cells Work?

Power Grid, Solar Energy, , , , , ,
In the last two decades, the contribution of solar energy to the world’s total energy supply has grown significantly. This video will show how a solar cell or photovoltaic cell produces electricity. Energy from the Sun is the most abundant and absolutely freely available energy on planet earth.

In order to utilize this energy, we need help from the second most abundant element on earth sand. The sand has to be converted to 99.999 % pure silicon crystals, to use in solar cells. To achieve this, the sand has to go through a complex purification process as shown.

The raw silicon gets converted into a gaseous silicon compound form. This is then mixed with hydrogen to get highly purified Polycrystalline silicon. These silicon ingots are reshaped and converted into very thin slices called silicon wafers.

The silicon wafer is the heart of a photovoltaic cell. When we analyze the structure of the silicon atoms, you can see they are bonded together. When you are bonded with someone, you lose your freedom.

Similarly, the electrons in the silicon structure also have no freedom of movement. To make the study easier, let’s consider a 2d structure of the silicon crystals. Assume that phosphorus atoms with five valence electrons are injected into it.

Here, one electron is free to move. In this structure. When the electrons get sufficient energy, they will move freely. Let’s try to make a highly simplified solar cell only using this type of material.

When light strikes them, the electrons will gain photon energy and will be free to move.. However, this movement of the electrons is random. It does not result in any current through the load. To make the electron flow unidirectional, a driving force is needed. An easy and practical way to produce the driving force is a PN junction. Let’s see how a PN Junction produces the driving force. Similar to n-type doping, if you inject boron with three valence electrons into pure silicon, there will be one hole for each atom.

This is called p-type doping. If these two kinds of doped materials join together, some electrons from the N side will migrate to the P region and fill the holes available. There. This way, a depletion region is formed where there are no free, electrons and holes.

Due to the electron migration, the N-side boundary becomes slightly positively charged. And the P side becomes negatively charged. An electric field will definitely be formed between these charges.

This electric field produces the necessary driving force. Let’s see it in detail. When the light strikes the PN Junction, something very interesting happens. Light strikes the N region of the PV cell and it penetrates and reaches up to the depletion region. This photon energy is sufficient to generate electron hole pairs in the depletion region. The electric field in the depletion region drives the electrons and holes out of the depletion region.

Here we observe that the concentration of electrons in the N region and holes in the P region become so high that a potential difference will develop between them. As soon as we connect any load between these regions, electrons will start flowing through the load.

The electrons will recombine with the holes in the P region after completing their path.. In this way, a solar cell continuously gives direct current. In a practical solar cell you can see that the top N layer is very thin and heavily doped, whereas the P layer is thick and lightly doped. This is to increase the performance of the cell. Just observe the depletion region formation here. You should note that the thickness of the depletion region is much higher here compared to the previous case.

This means that, due to the light striking the electron hole, pairs are generated in a wider area compared to the previous case. This results in more current generation by the PV cell. The other advantage is that, due to the thin top layer, more light energy can reach the depletion region.

Now, let’s analyze the structure of a solar panel. You can see the solar panel has different layers. One of them is a layer of cells. You will be amazed to see how these PV cells are interconnected. After passing, through the fingers, the electrons get collected in busbars. The top negative side of this cell is connected to the back side of the next cell through copper strips. Here it forms a series connection.

When you connect these series connected cells, parallel to another cell series, you get the solar panel. A single PV cell produces only around 0.5 voltage. The combination of series and parallel connection of the cells increases the current and voltage values to a usable range.

The layer of EVA sheeting on both sides of the cells is to protect them from shocks, vibrations, humidity and dirt. Why are there two different kinds of appearances for the solar panels? This is because of the difference in the internal crystalline lattice structure.

In polycrystalline solar panels, multi crystals are randomly oriented. If the chemical process of silicon crystals is taken one step further, the polycrystalline cells will become monocrystalline cells.

Even though the principles of operation of both are the same. Monocrystalline cells offer higher electrical conductivity. However, monocrystalline cells are costlier and thus not widely used. Even though running costs of PV cells are negligible.

The total global energy contribution of solar voltaic is only 1.3 percent. This is mainly because of the capital costs and the efficiency constraints of solar voltaic panels which do not match conventional energy.

Options. Solar panels on the roofs of homes have the option to store electricity with the help of batteries and solar charge controllers. However, in the case of a solar power plant, the massive amount of storage required is not possible.

So generally, they are connected to the electrical grid system in the same way that other conventional power plant outputs are connected. With the help of power. Inverters DC is converted to AC and fed to the grid.

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Source : Youtube

How to Select the Best Solar Panels – Four Things You Don’t Want to Overlook

Solar Energy, Solar Equipment, ,
My name is Charles Fox. – And I’m Warren Miller. – And in this video, we’re gonna talk about how to choose solar panels.  There are a lot of different panel manufacturers out there. And so we’re gonna talk to you briefly about what you should be looking for when you look at different solar panels.

Yep, so there’s not only a lot of different solar panel manufacturers, but there are different types of solar panels. There are the monocrystalline and polycrystalline solar panels. And you may have heard those terms, but I’d say don’t get caught up in whether or not you’re looking for a monocrystalline or polycrystalline panel.

They have similar efficiencies. Just be aware that the monocrystalline panels typically have a darker, blacker hue to them, and the polycrystallines have more of a blue hue to those panels. – That’s right.

Yeah, good point, Warren. The other thing you should consider is the panel production. So each panel’s going to produce a certain amount of watts. And what we’re seeing is that over time, panel manufacturers are producing panels that are incrementally getting more efficient.

What that means is with the same amount of space that panel is able to produce a little bit more solar power. So over time we’re seeing panel efficiencies increase. And so if you’re looking at solar, you want to make sure you have something that’s kind of within the market range at the time you install.

Absolutely. And I think one of the most important aspects when picking out a solar panel is to look for the warranty and the company behind that warranty. – Yeah. And it should be stated that most panel manufacturers, at least the mainstream– – Yeah.

They’re going to have a 25-year warranty. And that is typically just the panel itself. Then they have an output guarantee, so there’s typically two warranties that come with every panel manufacturer, or the panel manufacturers apply to their panel.

And we often attribute the overall warranty to the production warranty. And your production warranty is much more important than your panel warranty. So Warren, help us understand a little about the differences of those two in more detail.

Sure. The production guarantee guarantees that that particular solar panel will continue to produce electricity for 25 years. Most solar panels have a 25-year production guarantee, meaning that in 25 years, it’ll be producing what it’s guaranteed to produce, which they do degrade slightly over time.

But most panels should be producing about 85% of their initial output by the 25-year mark. The warranty or the hardware warranty that comes with it is typically 10 or 12 or 15 years. And that’s to cover the physical components of the solar panel.

Yep. The last thing you should really look at when you’re looking at different solar panels is, is the company that’s manufacturing the solar panel that you’re looking at, are they financially stable? Are they making a profit? And the reason that it’s so important is this is a long-term investment.

And you want that panel company, that panel manufacturer to be around in future years, if you would ever have an issue with a panel that is no longer operating as it should. So they need to be there to stand behind their warranty.

So if they’re not making money today, that’s a good indication or it should be a red flag that they may not be sustainable over the long-term. – Yeah. I would argue, Charles, that that’s probably one of the most important features.

It is. – Obviously you want to pick a high quality panel that’s efficient, but you want to make sure that the company that manufacturers that panel is gonna be around in 25 years to support those warranty claims.

Yep, and a lot of that data’s public. If a company is publicly traded, you can do your own research. You can call us. We’d be glad to look at that for you. Thank you so much for watching this video.

Hopefully you found this helpful.

Source : Youtube

ARE ALL SOLAR PANELS BUILT THE SAME? Permanent vs Portable vs Solar Blankets

Solar Energy, Solar Equipment, , , , , ,
G day, everyone today we’re going to go through the question of whether all solar panels are built the same. This is all the essential info you need to know before deciding on a solar panel for your setup.

This is a crash course in solar energy without all the marketing hype so settle in the latest. Data from the Australian Government’s Geoscience Department tells us that Australia has the highest solar radiation on average on earth.

That means we get the most sunlight per square metre looking at it. Another way before we had a single solar power station covering 50 by 50 kilometres, with an efficiency of just 10 % about half the current consumer grade efficiency.

It would be sufficient to meet all of Australia’s electricity needs. It’s for all these reasons that solar power makes so much sense for your camping or full driving setup. Plus, it’s easy to use and reliable.

It doesn’t require fuel, so it’s clean and quiet, and these days it’s relatively inexpensive. Okay, let’s get into the most commonly used solar panels for camping and for driving and their uses. First, there are permanent solar set ups.

That means that while you’re driving a vehicle or while you stopped at camp or even while, you’re parked you’re charging your auxiliary battery with the right setup, your solar is taking the load off your alternator and saving your fuel.

Even if it’s a minor improvement, it’s still an improvement. There are a couple of options: glass covered panels with alloy frames are common and they offer a good combination of strength and durability, and then there are semi flexible panels that are gaining popularity, they’re much lower profile.

Lighter weight and can be shaped to gentle curves, so they can fit almost anywhere next. There are your portable solar panels. These offer the benefit that you can choose when to pack them. So if your vehicle is a daily driver, you might need to keep the roof rack free or you don’t need to carry solar around all the time.

The most common types are folding solar panels and folding solar blankets and both have their pros and cons of solar panels. A more cost effective and offer more power for their size, plus most will come with folding legs.

That mean you can angle the panel towards the Sun, the higher efficiency, but solar blankets are much more portable, lightweight and easier to transport and store some solar. Blankets do offer fall out legs for the best of both worlds.

All solar panels are most effective when they’re pointed directly towards the Sun and they’re kept relatively cool, so whether you choose permanent solar or portable solar, keep those two things in mind: you’ll need to point them towards the Sun as best you can and keep them well.

Ventilated Plus think about the type of camping and four wheel, driving that you’re actually likely to do. If you spend most of your time sitting around at camp, then a couple of big portable panels or blankets might be the way to do it.

They’re easy to pack easy to set up and easy to connect. That means you got power running into your vehicle, while you’re sitting at camp. Otherwise, if you’re doing long drives throughout the day, permanent solar might make more sense, particularly if you pair it with the right DC to DC charger with solar priority charging.

That means that, while you’re driving your solar panel will be charging your auxiliary battery first and then your alternator will pick up any slack plus, it means your old 12-volt set up is running off the one system, a very basic way to think about how solar works Is that it’s two layers of silicon sandwiched together and different materials added to each layer, so there’s an excess of electrons on one and an excess of holes or free space on the other? Now, in this case, the top layer has an excess of electrons and the bottom layer has an excess of holes.

Those electrons want to travel through the cell to get to the holes when sunlight hits the solar cell, the light particles which are known as photons knock. The electrons out of those holes and back to the top layer where, instead of going back to the holes, they travel along these thin wires known as fingers, and then these thicker wires known as bus bars after that they go through your battery, delivering charge.

Then, back to the base layer where the process is repeated, each of these solar cells is only very low voltage and very low current, which is why connecting many of them together gives you enough usable output to charge your batteries generally more cells equals higher output.

Not only do you need to think about what type of solar panel best suits your setup, but you also need to think about the actual construction of the cell. The three most common consumer grade solar panels on the market will either be monocrystalline, polycrystalline or amorphous silicon.

Each type has its own pros and cons so starting with amorphous thin film solar. Now they are slightly better in low light and cloudy conditions, they’re, thinner and more flexible, but that comes at a massive cost, they’re much more expensive to produce and buy and they’re much less efficient, you’d need about twice the surface area of a monocrystalline or polycrystalline.

To get the same energy output, the absolute top shelf amorphous solar cells are about 10 percent efficient, so they’re able to convert about 10 percent of sunlight into usable energy. Next up we’ve got polycrystalline solar.

These are the cheapest to produce, which means they’re the cheapest. For consumers to buy and they’re more efficient than amorphous panels, however, because of the way they’re produced, which is pouring molten silicon into a mold, they cool at different rates, so you’ll see fractures and cracks.

Now they lead to inefficiencies overall, they have a maximum efficiency of just over 22%. Finally, there’s monocrystalline solar yeah. This is the most efficient for its size and it performs slightly better than polycrystalline as it warms up and in low-light conditions, but it costs more to produce and that’s because it’s made from a single piece of silicon.

That means, though, there’s no cracking or fractures, and you do get an efficiency boost about 26.5% overall efficiency, that’s more than the polycrystalline and much more than the Amorphous. These figures are achieved in ideal conditions in the lab, with a single solar cell.

So in the real world, with real solar panels, those figures will vary, but it’s a good place to start when you’re thinking about what type of solar you need for your setup before choosing a solar panel, do your research and find out what cell technology the Panel is the next thing to look for on each cell is the number of bus bars? As I said earlier, when sunlight hits the solar cell, it knocks electrons free from the silicon.

They then travel along the fingers, which is the thin wires and then the thicker wires known as bus bars. If fingers are the back roads, then bus bars are the highways, and that means the more the better.

Not only do you get higher efficiency, but you get better durability and longevity as well early consumer grade solar cells had two bus bars. Then they evolved into three and more recently, four and five.

So that means, if you’re looking at a solar panel, make sure it’s got four or even better. Five bus bars any less than four and it can be sure that it’s old, outdated stuff, that’s probably being sold at a clearance price plus.

If you have an older panel, that seems to be underperforming and it’s got two or three bus bars. It might be the time to upgrade. Bus bars can appear silver like this, or they can be coated with black silicon, which might make them look nicer, but it actually leads to a tiny loss in efficiency.

There are some exceptions to the bus bar rule, though, because bus bars are on top of the cell, they create shade, which means a loss in efficiency. So new technology, like shingles cells, are shaking up the industry.

They have bus bars on each end of the cell, which overlap like a tiled roof of the house. That means even better efficiency, more power and longer life, but the trade-off is that they’re more expensive too.

Another thing to keep an eye out for when you’re shopping for a solar panel system is what grade or class the solar cells are, that make up the panel so a grade A or Class A means that there’s no visible defects there.

A uniform colour and the output is within specifications, grade B or Class B cells show minor defects, scratches yellowing or tiny parts of the busbar missing, but the electrical data is within specifications, Class C or grade C cells show visible defects, including chips or cracks large missing Sections of bus bars and the electrical data is not within spec.

Finally, plus D or grade D cells are essentially rubbish with major defects, breakages or damaged. Finally, it’s important and compare each solar panel you’re, looking at like the like solar manufacturers and retailers, use the same standard test conditions in the lab to rate their solar panel wattage.

They light up the panel with a thousand watts per square meter of light and then set the ambient temperature up to 25 degrees Celsius. Then they simulate the amount of atmosphere that the light needs to pass through.

That’s the am 1.5 figure here AM stands for air mass 1.5. Air mass is a good average for most areas as it represents the sun coming through the atmosphere on a slight angle, directly overhead. It have an air mass of 1 and, as the sun goes close to the sunrise or sunset, the number would increase has to go through more atmosphere.

The next thing you’ll see on your solar panel specifications is the normal operating cell temperature. Now, that’s the temperature that your solar panel will reach in normal operating real-world conditions, so 800 watts per square meter of light 20 degrees ambient and about a 3.

5 kilometre per hour wind. Now the back of the panel is elevated, so it’s ventilated as well a solar panels. Normal operating cell temperature might be listed as high as sixty degrees Celsius, but the lower the number the better because it means the panel is more efficient at dispelling Heat and that’s important because for every degree of solar panel reaches above 25 degrees, it could be losing Around half a percent efficiency, so here’s a hot tip the reason power decreases, while temperature increases is because each individual cells voltage drops as they heat up.

The good news, though, is that the current increases as the temperature increases. So if you have a DC DC charger with an MPPT regulator, it can take advantage of that extra current plus boost the voltage to the correct level that your battery requires.

Although you’re losing some power due to the heat of the panel, the MPPT is more capable of then outputting the correct power to correctly charge a battery. My last piece of advice is to go for a more powerful solar setup than you.

That means no matter. The conditions you can always keep your batteries charged up any campsite running smoothly. Now whether that means you opted for a bigger permanent solar panel or at a portable solar panel, tear setup which is easy to use whenever you need it.

Tricks and techniques cheers guys.

Source : Youtube