Solar Panel Options and Selection Methodology
There are a handful of major types of solar panels and many innovations in developing other types of more efficient panels. I will discuss some of the available options and how to choose the correct size for your system. I went with a 12 Volt 100 Watt sized panel, so I will use this size as an example.
Monocrystalline VS Polycrystalline VS Thin Film Amorphous Panels
Monocyrstalline panels are created with a single uniform silicon crystal. Visually they have the same color throughout the panel. This type of panel is usually the most energy efficient option which also means they will take up the least amount of space to produce the same energy as other types. The downside is they are slightly more expensive, but I believe the cost is worth it for the higher quality and efficiency.
Monocrystalline VS Polycrystalline VS Thin Film Amorphous Panels
Monocyrstalline panels are created with a single uniform silicon crystal. Visually they have the same color throughout the panel. This type of panel is usually the most energy efficient option which also means they will take up the least amount of space to produce the same energy as other types. The downside is they are slightly more expensive, but I believe the cost is worth it for the higher quality and efficiency.
Polycrystalline panels are made of more than one silicon crystal and the purity of silicon is lower. The manufacturing process is easier and there is less silicon waste. These panels are less visually appealing because they aren't uniform. These panels are slightly less efficient, but make up for this with their low cost. Since they are slightly less efficient polycrystalline panels will take up more space than monocrystalline panels of the same energy output. If space isn't an issue and low cost is more important to you than efficiency, polycrystalline panels are a great option.
Thin Film Amorphus Panels are the least efficient of the 3 options that we are discussing here, so they will require the most space for the same amount of power. Their cost is said to be lower than monocrystalline panels, but I have yet to find a reliable high quality supplier of these panels at a low cost. When I find a reliable supplier I will add a link to their product. so you can get a better understanding of these panels. Their warranty and lifespan are both shorter than the other panel types. However, they have the added benefit of being extremely light weight and flexible which opens them up to applications such as mobility and stealth in appearance. They are uniform in appearance and visually more pleasing than the polycryrstalline panels. If your number one goal is mobility, flexibility, or mounting stealthily this panels are the way to go.
Panel Size Selection
The wattage size of your panel will determine how fast your batteries will charge. You can determine how fast your batteries need charged based on how much power you will be using in a given time and how many peak sun hours your geographical location receives. I will provide equations and resources in the future to calculate this, but I don't want to overwhelm anyone yet.
You will also have the choice to select between 12V, 24V, or 48V nominal voltage size panels. If you plan on using a large amount of power I would suggest going with a higher nominal voltage panel because the higher your nominal voltage the lower your current will be. Having a lower current means you can use smaller wire that is much easier to work with. A 12V system quickly reaches high amperage currents that can require wire sizes too large to reasonably connect. Remember that multiple 12V panels can be connected to make a 24V or 48V system as well. I will add a wiring diagram picture to show how you would connect them.
Mounting Hardware and Angles
In a perfect ideal situation you would have a mounting system that has your panels at an angle as well as a solar tracker that will keep your panel continuously facing the sun at all times of the day and year. For most small scale systems the additional cost of mounting this way is not worth the additional efficiency that it will produce. A more reasonable method is to mount your panel at a fixed angle facing solar south if you live north of the equator. Realize that solar south and magnetic south are different. There are many resources available online for more in depth research on specific angles and directions to optimize efficiency.
I chose to simply mount my panels flat on top of my van roof. I did this because it was the easiest mounting option and I don't mind losing the efficiency that an angle mount would provide. Also for a mobile option like my van the panels would have to be able to move from an angle to a flat mount for driving purposes any time I moved which was unreasonable in my situation. I ordered the HQST 12V 100 Watt Monocrystalline Solar Panel that is pictured above. I had to order mounting brackets for my situation separately. These brackets allow you to mount the panel fixed on a flat surface and provide you with a bit of clearance from your surface. I replaced the screws with bolts and lock nuts since I wanted a more secure fit and had access to the inside of my van where the holes would were drilled. I will add pictures of the panels mounted on my van roof in the future.
Solar Panel Wire Connectors
Almost all solar panels will come with two wires that have MC4 Connectors at the end. These MC4 connectors create a waterproof connection allow you to link multiple panels together easily. There are a male and female MC4 connecters, and they simply snap together. If you are building a solar generator you will most likely need an MC4 extension cable unless your panels and battery bank are extremely close together. Usually battery banks are kept inside in a waterproof and insulated.
The wattage size of your panel will determine how fast your batteries will charge. You can determine how fast your batteries need charged based on how much power you will be using in a given time and how many peak sun hours your geographical location receives. I will provide equations and resources in the future to calculate this, but I don't want to overwhelm anyone yet.
You will also have the choice to select between 12V, 24V, or 48V nominal voltage size panels. If you plan on using a large amount of power I would suggest going with a higher nominal voltage panel because the higher your nominal voltage the lower your current will be. Having a lower current means you can use smaller wire that is much easier to work with. A 12V system quickly reaches high amperage currents that can require wire sizes too large to reasonably connect. Remember that multiple 12V panels can be connected to make a 24V or 48V system as well. I will add a wiring diagram picture to show how you would connect them.
Mounting Hardware and Angles
In a perfect ideal situation you would have a mounting system that has your panels at an angle as well as a solar tracker that will keep your panel continuously facing the sun at all times of the day and year. For most small scale systems the additional cost of mounting this way is not worth the additional efficiency that it will produce. A more reasonable method is to mount your panel at a fixed angle facing solar south if you live north of the equator. Realize that solar south and magnetic south are different. There are many resources available online for more in depth research on specific angles and directions to optimize efficiency.
I chose to simply mount my panels flat on top of my van roof. I did this because it was the easiest mounting option and I don't mind losing the efficiency that an angle mount would provide. Also for a mobile option like my van the panels would have to be able to move from an angle to a flat mount for driving purposes any time I moved which was unreasonable in my situation. I ordered the HQST 12V 100 Watt Monocrystalline Solar Panel that is pictured above. I had to order mounting brackets for my situation separately. These brackets allow you to mount the panel fixed on a flat surface and provide you with a bit of clearance from your surface. I replaced the screws with bolts and lock nuts since I wanted a more secure fit and had access to the inside of my van where the holes would were drilled. I will add pictures of the panels mounted on my van roof in the future.
Solar Panel Wire Connectors
Almost all solar panels will come with two wires that have MC4 Connectors at the end. These MC4 connectors create a waterproof connection allow you to link multiple panels together easily. There are a male and female MC4 connecters, and they simply snap together. If you are building a solar generator you will most likely need an MC4 extension cable unless your panels and battery bank are extremely close together. Usually battery banks are kept inside in a waterproof and insulated.