Solar panels: What you need to know
Green energy is becoming increasingly popular as it is one of the best eco-friendly energy solutions for homeowners. A solar panel is a group of electrically connected solar cells enclosed in a frame that converts sunlight into electricity. Switching to solar energy has many advantages. Find out more about solar panels in this article:
Solar panel: What’s that?
A solar panel converts sunlight into electricity or heat. Solar energy can be used to power a house or building. A solar panel is made out of many small solar cells. They are combined to cover a large surface in order to produce enough electricity. The more light the cell is exposed to, the more electricity or heat it produces.
Solar panels: A brief historical overview
Solar energy technology is not a new discovery. It goes back to the mid-1800s, to the industrial revolution, when solar power plants were developed to heat water and create steam to power machines. The development of solar cell technology, or photovoltaic (PV) technology, began during the Industrial Revolution when French physicist Alexandre Edmond Becquerel first demonstrated the photovoltaic effect—the ability of a solar cell to convert sunlight into electricity—in 1839. About four decades later, American inventor Charles Fritts created the world's first rooftop solar panel in New York in 1883, one year after Thomas Edison opened the first commercial coal-fired power plant. The panels were then covered in selenium and did not produce much current. However, the process of electricity production by light was not fully understood until Albert Einstein wrote his groundbreaking article on the photoelectric effect in 1905 that won him the Nobel Prize in Physics in 1921.
Solar panel: How does it work?
Solar thermal systems:
Solar thermal systems operate on the basis of the solar heating process. They absorb energy from the sun, and convert it into heat that can be transferred to a home or business building for heating or water heating. The heat is generated by solar panels (collectors) on the roof.
Solar thermal systems can be combined with a boiler or collector, allowing the heat generated by the sun to be transferred to the heated fluid and antifreeze. The water is then pumped into a heat exchanger inside the water tank.
Photovoltaic systems (PV systems):
A solar panel (PV) consists of various photovoltaic solar cells. The cells are small and produce about 1 or 2 watts of power each. To get the most power out of them, the cells are connected to a larger unit: the solar module. The photovoltaic solar panel can be connected to another larger unit to form a grid that produces even more power.
Solar panels: Efficiency
In simple terms, solar panel efficiency (in percentage) quantifies the ability of a solar panel to convert sunlight into electricity. If two solar panels with different efficiency indices are exposed to the same amount of sunlight for the same amount of time, the most efficient panel will produce more electricity than the other.
Let’s take two solar panels of the same size. One has an efficiency of 21% and the other of 14%. Panel number 1 will produce 50% more kilowatt hours (kWh) of electricity under the same conditions compared to panel number 2. Thus, go for the most efficient solar panel to maximize energy production and save more money on your electricity bill.
For many solar energy users, efficiency is the key quality aspect when choosing solar panels. Although this is an important criterion, it is not the only one to be considered when considering the purchase of a solar panel. The efficiency of a solar panel depends on the panel's ability to convert energy at a lower cost and with a high power supply.
Solar panels: Efficiency in winter
You might be surprised to learn that cold weather in winter times might actually improve the performance of solar panels. Production losses due to snow or little daylight hours are mostly minimal. With photovoltaic (PV) technology, it is easier to convert sunlight into colder energy. A solar panel can also capture additional sunlight as it is reflected by snow.
Solar panels: Efficiency during snowfall
Snowfall is another problem that might affect the efficiency of solar panels. However, it is not such a serious a problem as you might think. Snow is lightweight and thus only has minor effects on solar panels. It will usually melt before it causes real problems. Solar panels are generally designed to allow as much snow as possible to slide. Even heavy snowfall is unlikely to block your solar panels.
Snow can also allow the solar panel to produce more electricity. How? The white snow reflects sunlight like a mirror. This is also the reason why skiers are prone to sunburns. This can improve your solar panels’ efficiently.
Solar panels: Durability
You might be familiar with the idea that the same solar installation can produce different results on different houses. Choose your solar installation’s position wisely: Take into account the location of your house and the amount of sun the installation would receive throughout the year. We take into account a number of factors; trees, roof angle and size, temperatures... All these factors are important for your installation to work properly on the long term. A professional company can guarantee the future production of your solar panels and provide you with useful information on all the components so you can maximize your power production.
Solar panels: Price
How much does a solar panel cost? This is one of the most frequently asked questions. However, there is no simple answer. We want to try and shed light on all aspects of the question in this article.
Residential solar systems are between 3 and 8 kW in size on average and cost between 15,000 and 40,000 euros. The cost per watt (price for parts, labor, issue costs, overhead and profit) has decreased significantly over the past decade and currently stands at 6 to 8$/W in the United States.
Solar panels: The different panel types
Monocrystalline solar panels: the most efficient
Monocrystalline solar panel, as their name suggests, are made of a single continuous crystal structure. It is the oldest and most developed PV technology. This is the most efficient solar panel type. It uses a special manufacturing technique to process the main raw material, silicon. Very high purity silicon ingots are cut into thin grid-mounted wafers. The panels are black and each silicon wafer has rounded corners, which makes these types of panels easily recognizable. However, monocrystalline panels are quite expensive. These high-end panels are much more expensive than other type, although costs can vary considerably depending on the manufacturer and design. Manufacturing monocrystalline solar panels also produces more waste due to the cylindrical shape of silicon ingots. The edges of each wafer must be cut and disposed of
Polycrystalline solar panels: best value for money
I'M.SOLAR manufactures polycrystalline solar panels. These solar panels are manufactured from molten silicon. It is cast and cut into perfectly square wafers. The melting process uses almost all the material, limiting waste during manufacturing.
However, polycrystalline solar panels are less efficient than monocrystalline panels due to their lacking heat resistance. They produce less electricity from the same amount of sunlight. There are also differences in design: Polycrystalline panels tend to be larger and their shimmering blue colour may be less aesthetically pleasing compared to thin-film and monocrystalline panels.
Thin-film solar panels: lightweight and portable
You have probably heard about thin-film solar panels. They are newer and rarely used for private housing yet. However, they are gaining in popularity. I’M.SOLAR manufactures thin-film solar panels. A photovoltaic element, such as amorphous or organic silicon photovoltaic cells, is applied layer by layer. Thin-film solar panels come with many advantages. They are lightweight and their efficiency is not harmed by shading or obstruction problems. They perform well even in low-light conditions. This panel type is well-suited for mass production and affordable. But thin-film solar panels also have a few disadvantages. Thin-film panels come with a rather low efficiency, ranging from 7 to 13%, with an average efficiency of about 9%. These panels also require a lot of space. There are mostly a great solution for commercial applications. They are generally ill-suited for residential installations with limited space. Thin-film panels are also more expensive as they require a lot of additional equipment such as mounting systems and cables. In addition, thin-film panels mostly do not last very long and are quickly affected by the weather. You probably will not find a manufacturer offering a long-term warranty on thin-film panels.
Other parts of solar panels:
A solar panel is not only made out of solar cells. It typically includes a durable glass housing which protects the silicon PV cells. Under the glass exterior lies an insulating layer as well as a protective sheet to hinder heat dissipation and prevent moisture build-up inside the panel. Insulation is important because an increase in temperature will lead to a decrease in efficiency, which will reduce the performance of the solar panel.
Solar panels also have an anti-reflective coating that increases sunlight absorption and allows the silicon cells to maximize their sunlight exposure. Silicon solar cells come in two varieties: monocrystalline or polycrystalline. Monocrystalline cells consist of a single silicon crystal, while polycrystalline cells are made out of fragments or chips of silicon. Monocrystalline panels give electrons more space to move around and are therefore more efficient compared to polycrystalline panels. However, this comes at a cost: Monocrystalline panels are more expensive.
Can you build your own solar panel?
A solar panel is a set of solar cells. You can easily put a solar panel together yourself with cells that you buy online. Things get much more interesting, however, if you build your own cells from scrap materials. All you will need is flashing copper foil and salt water. The cells will generate measurable electrical current from sunlight. A single cell does not generate much power, but if you build many of them and connect them in series, you can generate enough current to charge a battery or light a bulb.
The theory behind the copper cell:
When Heinrich Hertz discovered the photoelectric effect, he did not have access to doped silicon chips, but he did have metal plates. One of the plates most likely was copper that oxidized from exposure to the atmosphere, as copper oxide was one of the first materials used to show this phenomenon. It is quite easy to deposit a layer of copper oxide on a copper foil. You only need to heat it up.
Copper oxide is a semiconductor. If you immerse the plate in salt water and expose it to sunlight, electrons flow from it into the salt water. Then, place a clean copper plate in the water to act as an anode, and electrons will flow through it. If you connect both plates with a counter, the electrons return to the original plate through the counter, and it will record the electrical current.
Preparing the copper plate:
You will need about half a square foot of flashing copper for this project, which can be found in most hardware stores. Cut it into two same-size pieces. Wash the copper pieces with soapy water to remove grease, then place one sheet on the burner of an electric stove. The part should cover the whole burner.
Turn the burner on and watch. The colours of the copper piece intensify, then begin to darken with a layer of cupric oxide. Wait until the copper is black and let it then heat for another 30 minutes. Turn the burner off and let the copper cool down on the burner.
As the plate cools, copper and copper oxide contract at different rates and the black coating begins to flake. When the plate is completely cold, remove it from the burner and gently remove all the product that comes off. Underneath is a red layer of copper oxide. Don't rub this: It's the semiconductor layer you need.
A solar cell in a bottle
A transparent one-litre plastic bottle is a suitable container for your solar cell. Cut the bottle in half and remove the top to make an open container. Bend the copper plate you have heated into a semi-circle and insert it into the bottle so that it rests against the side. The side facing the burner should be facing outwards in the bottle. Bend the copper plate you have not heated in the same way and place it in the opposite side of the bottle. The plates should not touch.
Mix two tablespoons of table salt with 2 cups of warm water in a glass and stir until the salt dissolves. Pour the salt water into the plastic bottle and fill it about 3/4 full. The top of the metal plates must be above the water to attach crocodile clips. Your cell is now ready to generate electricity.
Remove the cell and place it on a table so that the oxidized plate is exposed to the sun. Connect a counter to the plates with crocodile clips and adjust the counter to record the current in microamperes. When the cell is in full sunlight, the counter should record between 33 and 50 microamperes. Switch the multimeter to volts: You should record a voltage of about 0.25 volts. To calculate the maximum power (P) supplied by the cell, multiply the maximum current (I) by the voltage (V) , which should be 0.00005 amperes x 0.25 volt = 0.0000125 watts or 12.5 microwatts. The formula expressing this relationship is P = V x I.
Link the cells to increase power
A solar panel is simply a set of solar cells wired in series. Although the cells of commercial panels are flat, it is possible to create a panel made out of of cells in a bottle. Start with two bottle cells. Connect the anode of the clean copper plate to the cathode of the plate with copper oxide using a wire and crocodile clips. Connect the reader to the two plates that are not connected. You double the voltage by wiring two cells in series. Thus, you just doubled the power of your network according to the formula P = 2V x I. You can connect as many of these cells in series as you wish. Each new cell increases the voltage by 0.25 volts.
It is not technically difficult to manufacture a single solar panel or a small batch (it mostly requires soldering skills), but the best materials such as solar glass and solar protection sheets are generally not available to the public. Also, please bear in mind that building solar panels with the wrong equipment can be dangerous.
Solar panels: installation guide
First of all, make sure that your roof or the place where you will install your solar panel is strong enough support its weight. There is no point in installing a solar panel on a roof that will collapse and eventually cost you more money to repair.
Unless you use solar roof tiles, measure the dimensions of your roof and make sure that your solar panels (the entire solar installation) will fit. Bear in mind that you might want to enlarge your solar installation by adding solar panels in the future. The solar panel must be placed on a roof facing in the direction of the sun. This means that, if the sun rises in the east in your region, your panels should face east for maximum exposure. Also make sure that the roof is not shaded by trees, buildings, etc.
One more thing about installing solar panels: Shade can prevent your solar panel from working. Bear in mind that shade changes with the seasons and that the future development of your neighbourhood might bring about some changes. Install solar panels at least 12" from the edge of the roof and 16" from the eaves.
Before installing solar panels, you must install brackets on sloped roofs or mounting rails on flat roofs. Solar panel holders can be purchased in home improvement or solar stores. The brackets or rails should be attached to the rafters or trusses of the house, not just the siding. Supporting systems for sloped roofs exist, but the slope must be placed in such a way as to give the panel direct exposure to the sun. Use a mounting rail system to allow you to position the panels in the angle you want. It is important to keep all solar panels at exactly the same angle and height (even when the roof slope changes) so that the voltage production will be the same. When you drilling screws into the roof to fix the brackets or mounting rails, be sure to use roof sealing compound to prevent rainwater from leaking through the holes in your roof. Follow the instructions provided with the brackets or rail system to ensure that your solar panel installation complies with the manufacturer's recommendations.
- Then, lift your solar panels onto the roof on the brackets or mounting rail system and attach them to it. Always secure the panels and make sure they do not accidentally slide off the roof.
- When the installation is complete and your panels are secure, connect them together depending on how you want them to produce energy. Make sure all your wires are properly insulated and waterproof (wrapped in black electrical tape). Always connect a ground wire from the mounting material to the ground during installation to avoid shocks.
Once the solar panel is connected and aligned, the duct must be passed under the panels, in a junction box, on the side of the house and on the first photovoltaic component of your system—usually the DC disconnection (see Typical solar systems and the correct order of PV components).
You must use "wiring" composed of three wires: a negative, a positive and a ground wire. None of the cables should touch the roof. Installing a conduit on all wires coming out of your solar panel is essential to protect them from rain, sun and other elements.
Now configure all your photovoltaic components according to the manufacturer's instructions (but do not connect them yet). Install your inverter and other photovoltaic components in a garage or a neighboring building. Make sure the area is dry, well ventilated and not subjected to extremely cold or hot temperatures. This is particularly important with regard to your batteries. Whether it's cold or not, please use a battery box to protect your batteries from changing outer conditions. A battery box also protects children and pets from accidental electric shocks.
The next step consists in plugging in your inverter and the other system components. Connect them to your home's AC circuit breaker panel. First, deactivate the main circuit breaker and turn off all AC and DC power sources. Then connect your inverter to your AC circuit breaker panel. Connect the PV wires to the DC disconnect switch and other components of the photovoltaic system until you reach the main DC disconnection. Then, connect the main Disconnect DC to the inverter.
Solar panels: the advantages
You are looking into fitting your home with a solar installation? These are the main advantages of solar panels:
Solar panels reduce air pollution
Solar panels transform sunlight into clean energy. Installing a solar panel on your home helps reducing greenhouse gas emissions and reduces our collective dependence on fossil fuels. Traditional electricity comes from fossil fuels such as coal and natural gas. When fossil fuels are burned to produce electricity, they emit harmful gases that are the main cause of air pollution and climate change. Fossil fuels are not only harmful to the environment, they are also a limited resource. As a result, their price fluctuates constantly and can increase drastically.
Solar panels reduce water pollution
Although the manufacturing process requires water at all stages, solar photovoltaic cells do not need any water to generate electricity. This is one of the most important advantages of solar energy in terms of environmental protection, even though it is not mentioned enough. Traditional biomass and geothermal power plants, such as natural gas and coal-fired power plants, require huge amounts of water for cooling. Solar energy does not pollute local water resources. Their operation (which requires NO water) does not interfere with local supplies as they do not compete with agriculture, drinking water supply and other vital water needs.
Solar panels reduce the use of scarce resources
Solar energy is renewable. The sun is the most abundant source of energy in the world, producing an incredible 173,000 terawatts of solar energy per second. This is more than 10,000 times the world's total combined energy consumption. And this energy can be used over and over again! Fossil fuels are not renewable. Although they may seem abundant today, we will run out of them sometime soon. The costs for searching and extracting fossil fuels will also rise. The continuous reliance on fossil fuels will lead to irreparable financial and environmental damage. Going solar today is the best way to protect yourself against the reality of limited fuel resources.
Safe money on your energy bill with solar panels:
If you are facing an increase in electricity costs, solar electricity can be an economical alternative. It also helps reduce your dependence from your local electricity provider. Wondering if these panels also work on cloudy days? No problem! The sun always emits energy, even on cloudy or rainy days. Solar panels are efficient all year long and allow to you save money year round, even in the coldest climates. Depending on the size of your installation, its efficiency and your home’s sun exposure, your panels might actually generate more electricity than you need for your home. You might then be able to reduce your monthly electricity bill to zero. Depending on the region you live in, you can get money back if your solar energy system produces excess electricity. Consult your local solar energy guidelines for more information.
Reduce fuel dependency with solar panels:
National oil reserves continue to decline, so alternative energy sources are more important than ever. Solar energy reduces a country's critical dependence on oil and protects everyone from considerable price fluctuations and the risk of electricity shortages caused by disruptions in oil imports. Solar energy offers obvious advantages over fossil energy sources. What are you waiting for? Join the "go green" revolution and install solar panels.
2019 will certainly be the most important year for solar energy in more than a decade. Contact one of our qualified solar integrators to start your solar project today!
Which solar panel should you choose?
According to the U.S. Department of Energy, polycrystalline silicon leads the market with 55% of photovoltaic technology deliveries in 2013, compared to 36% for monocrystalline. So far, research has produced polycrystalline cells with a maximum efficiency of 20.4%, with monocrystalline technology pushing the limits to 25%.
Whether grid-connected or not, on the roof of a house or a commercial building, space and surface are always limited in every solar project. Thus, efficiency is key for project developers. The efficiency of solar panels varies from 13 to 16%.
For most applications, monocrystalline or polycrystalline solar panels are the best option. These established technologies offer the right balance between price, efficiency and reliability. For most commercial and industrial uses, crystalline silicon is still the standard and will remain so for years to come.
Solar panels: major challenges
The solar sector is yet facing some major challenges it will have to overcome in order to fully replace fossil fuels:
Reliability of solar panels
One of the major problems of solar energy is reliability. At best, a solar panel can produce electricity 12 hours a day and will only reach its peak production for a short period of time, around noon. There are panels that follow the sun which may extend this main generation period a little. However, this still means that the panels produce at their maximum capacity only for a very little time each day. Batteries can be charged during peak periods to provide some energy at night, but they are expensive, contain toxic substances and wear out quickly due to repeated charging and discharging cycles.
One of the main obstacles to the widespread adoption of solar energy is the variations in its intensity. According to the National Renewable Energy Laboratory, the sun provides almost twice as much energy to the Mojave Desert as it does to the Pacific Northwest. Since the power of a panel depends on the amount of solar energy it receives, solar energy is a much better source of energy in the southern deserts than in other regions. Nevertheless, a solar panel can provide at least some free electricity anywhere in the world. However, it will take much longer for this investment to pay off in areas without intense solar coverage.
High costs for solar panels
The initial costs for a solar panel are quite high. You also need to buy solar equipment such as an inverter, solar storage batteries and cables.
Solar panel choice based on weather conditions
Although solar energy can still be collected on cloudy and rainy days, the efficiency of solar installations decreases in bad weather. Solar panel depend on sunlight to efficiently capture solar energy. As a result, cloudy and rainy days can have a significant effect on your power production. Remember solar energy cannot be collected at night. If you also need your water heating solution to operate at night or during winter, a thermodynamic panel might be the right choice.
Stocking solar energy is expensive
Solar energy must be used immediately or stored in large batteries. These batteries, used in off-grid solar systems, can be charged during the day so that energy can be used at night. It is a good solution for if you want to use solar energy all day long, but it is also quite expensive. In most cases, it makes more sense to only use solar energy during the day and to draw energy from the grid at night (you can only do this if your system is connected to the grid). Fortunately, your energy demand is generally higher during the day, so you can cover most of your energy needs using solar energy even if you use power from the grid at night.
While solar production is emission-free, manufacturing solar panels and associated products may involve certain environmentally harmful substances. Nitrogen trifluoride is a common by-product in manufacturing electronic products, including those used in solar cells. It is a greenhouse gas 17,000 times more powerful than carbon dioxide. In addition, many solar cells contain small amounts of cadmium, a toxic metal, and solar batteries might contain a host of heavy metals and hazardous substances. As solar technology improves, manufacturers may be able to move away from these harmful substances in the future.
Renewable energies VS fossil fuels:
The difference between renewable energies and fossil fuels:
Knowing the difference between renewable energies and fossil fuels is easy. Renewable energy comes from natural resources that replenish over the course of a normal lifetime. This includes:
- Solar energy
- Wind power
- Water energy
- Geothermal energy
Fossil fuels, on the other hand, can take thousands or even millions of years to recover:
Renewable energies grow faster than fossil fuels
Although natural gas has significantly increased its market share over the past decade, renewable energies have grown faster than fossil fuels. By 2016, renewable energy production in the United States reached a record capacity of 22 gigawatts, a much higher growth than that of fossil fuels. In Texas, wind power is already the main source of renewable energy, with nearly three times the megawatt capacity of any other state and a state-of-the-art grid to generate wind power. If an oil-rich state, such as Texas, can produce renewable energy in a sustainable way, we can assume that renewable energies will continue to surpass fossil fuels in the near future. .
Renewable energies are cleaner than fossil fuels
Since the beginning of the industrial revolution, the earth's temperature has risen at an alarming rate, raising ocean water levels in its wake. Fossil fuels not only cause global warming, they also generate unhealthy by-products, such as air pollution, that are detrimental to our health. Even if you are sceptical about climate change, you can see the effects of burning fossil fuels in the form of dirty smog, especially in large cities like Houston.
Renewable energies, on the other hand, generally emit less CO2 than fossil fuels. In fact, renewable energies such as solar and wind energy do not emit any CO2, except during manufacturing and maintenance. Renewable energies allow us all to breathe better, to stay cool and to pass out a healthy planet to future generations. When comparing renewable energy with fossil fuels, remember that renewable energy production is cleaner, easier to maintain over time, grows faster and is often even cheaper than fossil fuels. Visit the Amigo Energy blog to find out more about renewable energy and learn why protecting the environment is more important (and easier) than ever.
Remember this: The world is gradually shifting towards the "Go Green" revolution due to a growing awareness for environmental needs and the scarcity of natural resources. In response to these ecological concerns, I'M.SOLAR developed high-efficiency solar panels which allow it to provide its customers with clean, reliable and low-cost energy throughout the year.