Absorption of Light: Solar panels are made up of photovoltaic cells, typically made of silicon or other semiconductor materials. When sunlight hits these cells, they absorb photons (particles of light).
Absorption Of Protons: When photons are absorbed by the semiconductor material….
Generation of Electron-Hole Pairs: they transfer their energy to electrons in the atoms of the material. This energy excites the electrons, allowing them to break free from their atoms, creating electron-hole pairs.
Flow of Electrons: The freed electrons are then able to flow through the material, creating an electric current. The electrons travel through a conductor like copper or aluminum built into the cells.
Flow Of Electrons Continued: As seen in the photo the red arrows indicate the direction of electrons. The freed electrons travel through your conductors out to your external source for which you would like to power. The electrons complete the circuit after they fill in the electron-hole pairs. Because the electricity flows one way we call this (DC) or direct current.
Direct Current: This current has to go somewhere right? Unfortunately, we can’t use DC for most appliances they need AC or alternating current. This is where an inverter/charge controller comes in great! An inverter will take that direct flow of electricity and turn it into an alternating flow of electricity.
Power Storage: Now typically if you don’t have a battery hooked to your solar power your unused energy will be sent right to the grid. So at night, you won’t be able to use your solar panels, you will have to rely on and pay for energy from the grid. But if you have a battery and inverter hooked up to your solar panels you can send that unused energy straight to your battery for use at night time or whenever you need it!
Great! Now that you have a basic understanding of how solar panels work let’s look at some important aspects of solar power!
Series VS Parallel Connections: For series when you connect the panels together the volts will get multiplied by the number of panels you have. In this case, 12V x 3 panels will equal 36V. Since the current is staying on the same circuit loop the amps stay the same at 8A. But when we connect them in parallel the opposite happens because with each panel they have their own circuit. So in the second half of the image the amps increase because there are 3 different circuits connecting to one point, giving us 24A. The volts stay the same at 12V because each panel has its own voltage source.
Charge Controllers/Inverters: As you can see from the previous picture, no matter how you connect them you can get the same watts for the same amount of panels. But why focus on volts and amps? For example, if your charge controller operates between 100V and 150V, stay within that range not exceeding or dropping below those volts to avoid damaging your system. These systems are also important if you have a battery. If you don’t have a charger controller and only operate with a battery/panels you could overcharge the battery and damage it. But also at night when it isn’t being charged, it can actually discharge back through the solar panels!
Battery: Let’s get this straight, this equipment will not be cheap, especially your batteries. It’s important to check the ratings of the battery. We just learned overcharging is bad, but also you shouldn’t fully discharge your battery (use it until 0%) these both can lead the battery life span to drop. We call it a deep discharge and it can be avoided by using a low voltage disconnect. Lastly, if you don’t store your battery in the right temperatures it could also hurt the lifespan of your battery. So be sure to look at the optimal temperature and storage condition for your specific battery! Ensuring we take care of our battery and system will ensure the system and battery will take care of you for many years to come!
Key Terms:
Silicon– Is one of the most abundant materials found in the Earth’s crust. A non-carbon, chemical element. Although in its raw form, it looks metallic it is not.
Semiconductor– Think of this as a material that is right in the middle of something conductive for electricity like metal and something that is insulative to electricity like glass. Through this it helps control various electronics we use every day.
Photons– Basically this is the smallest form of light! These massless and really really tiny particles of light are a form of electromagnetic energy.
Atoms– These are tiny particles that are made up of everything known to humans, and that are so small it can even be hard to see on a microscope. The pieces that make up an Atom are even have smaller particles called Subatomic Particles like the center of the Nucleus. The nucleus is Protons and Neutrons. Protons are positively charged and neutrons are neutral. That means just the whole nucleus is positively charged. Now the final piece to an Atom is similar to something else you might know, planets! The way the planets orbit the sun an Atom has Electrons that have a negative charge, orbit the Nucleus. Now because the nucleus (center) is positively charged and the electrons (outside the Nucleus) are negatively charged they are electrostatically connected to each other.
Volts– They are like the flow of water but it’s electricity through a wire. The more water being pushed through the pipe (electricity) means more pressure and thus the higher the volts. The same goes for the opposite, the less water being pushed through the pipe the lower the pressure thus making it lower volts. You need the right amount of volts for the right electronics to work properly.
Amps– So volts are the push of electrical energy what are amps? Well, the amps will measure the actual amount of electricity flowing through the circuit. So imagine the smaller amount of amps flowing to a light bulb the dimmer the light is. The more amps flowing to a light bulb the brighter the light gets but also at the same time could burn it out!
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