If your roof does not have enough space for a solar array, the best option is the installation on the ground. But the question is, what is the ideal solar cable length? And can the length of solar cable influence the PV system’s efficiency? This is a question you must answer before any configuration. If it’s too far, you won’t get the desired results, so what’s the acceptable limit?
To answer the question “how long can solar panel cables be?”, we have to say you can install solar panels 100 meters away from your house, but this will need long and costly cables to avoid energy loss. 15 meters of solar cable length or less will have a voltage drop of 2%, and that is the current limit.
How Distance Affects Solar Panel Output
There are many reasons why solar panel ratings and actual output differ, but when it comes to distance, it’s all about the ideal solar wire length. The further the solar panels are from your house, the longer the cables should be to avoid too much energy loss. Long, thick lines are expensive and defeat the purpose of using solar power to save money. Your solar panel cables should not be any longer than you need them to be, that’s why it’s important to know what kind of solar structure to buy, to use solar cables efficiently.
If you can keep the solar cable length to 30 meters or fewer, the power and voltage drops will be 3% or less. If you are longer than 30 meters, you will need longer, thicker cables.
As current flows in an electrical circuit, voltage is lost due to the resistance of the wire. Longer wire strands produce more resistance, thus more significant voltage drops. You want to maximize output with solar panels, so use the shortest possible wire for installation.
According to the National Electrical Code, the voltage drop must be 3% or less. A distance of 30 meters between a solar panel and a house could result in a voltage drop of 3% or less, which is acceptable. As you go and reach 300 meters or more, the drop could be 3.7%. That’s assuming you use big, thick cables. Thin, flimsy cables could see a much higher voltage drop.
Lastly, make sure you only use high-quality cables. We recommend Apar solar DC cable, which work great with solar panels. The maximum length of solar cable is 35 meters, which is right at the acceptable limit for minimizing voltage drops. Although, having the maximum cable length for solar panel is not the best option efficiency-wise.
Solar Cable Length and its effect on solar PV systems
Theoretically, you can install solar panels from any distance, as long as you have enough cables. If you’re willing to use longer, thicker cables, you can install solar panels tens of meters from your house.
Suppose you have a barn, and you want to run it on solar energy. If the shed is 90 meters from your house, it’s better to install solar panels on the barn instead of using a 100-meter solar cable length. If the barn is not strong enough to support the roof solar panels, you can always go for a ground-mounted solar panel.
Solar power produces direct current (DC), which is vulnerable to power losses and voltage drops. The best way to avoid this is to shorten the distance from the panels to your house. A higher voltage solar system is ideal because they draw lower amps.
Low-voltage solar systems are more vulnerable to overheating due to the higher amperage. Long cables produce more heat, so a 48V system is more suitable. The greater the distance from the solar panels to the house, the higher the voltage.
How to connect the solar panels, charge controller, and battery
So now you have the correct solar cable length for the battery and solar panels. Is it time to configure the system? Not yet, because you also need a charge controller to ensure the battery runs smoothly and safely. As we have explained before, you should not connect solar panels directly to the battery. Doing so puts devices at risk of overcharging, overcharging, sudden power fluctuations, and more.
Here are the steps. The batteries and charge controller of your solar panels have labels where the connectors go. Please refer to your installation guide. But the process is similar to these.
Important: The charge controller must be close to the battery, no more than a meter away. It does not need to be close to the panels. If you set up your system before you get a controller, compare the difference in power loss. It is a lot less when you use a controller, especially an MPPT. Whether you use an MPPT or PWM, both will provide protection for your devices from changes in voltage.
Now you know the solar panel maximum wire length, and why it’s not ideal to have such long wires and cables running between your home and your solar PV system. For more information on solar dc cable length and the installation of solar cables, contact us at Pas Solar.