The Basics of an RV Photovoltaic System
A solar power system is a great way to be less dependent on electrical hookups when camping. It’s also a more environmentally friendly and quieter alternative to generators.
A solar power system consists of solar panels, batteries and a charge controller. It is important to properly size your system by determining your expected electricity usage, the amount of available roof space and whether you want to export energy to the grid.
Solar Panels
In order for an RV solar power system to work, it needs to have solar panels that convert sunlight into electricity. They can be either portable or permanently mounted on the roof of the RV. Permanently installed systems are wired directly into the RV’s house batteries and electrical system. This allows for the most efficiency as well as ease of use. There are also some legalities involved in having a permanently installed solar power system so it is important to consult with an expert in the field if this is your route.
Estimating energy needs is a critical factor in selecting the right size of a solar panel system. It involves calculating how many appliances and devices you will be running in your RV, their respective wattages and the peak usage times of these appliances. This information is then used to calculate the total wattage required by your RV. The result will determine the ideal panel wattage.
Once you have the correct size of a solar panel system selected it is then necessary to select the right type of solar panel. There are several options to consider including crystalline, polycrystalline and flexible panels. Each of these types has their own unique advantages and benefits. For example, flexible panels are more durable and lightweight than crystalline panels and require less roof space to install.
Batteries
The battery, or battery bank, is the heart of your RV solar power system. It stores the energy generated by your solar panels and then delivers it to your appliances when needed. The batteries are also the primary backup source in case your solar panels aren’t producing enough energy or if it is cloudy.
You can find several different types of deep-cycle RV batteries, including gel and flooded lead-acid batteries. Alternatively, you can use lithium batteries for your RV solar system, which are significantly more efficient and offer higher charge/discharge rates. Lithium-iron phosphate (LiFePO4) batteries are the newest and most advanced type of lithium battery for RVs. These batteries are more compact, lighter, have a longer lifespan, and a greater DOD (deep-discharge) rating than traditional lead-acid batteries.
A battery charger is used to rv photovoltaic system regulate the flow of power from the solar panels into the battery bank. It prevents overcharging and prolongs the life of your batteries. There are two main types of charge controllers: MPPT and PWM.
The charger connects to the positive and negative terminals of each battery in your battery bank. It is important that these connections are made properly. Often, do-it-yourself installers make mistakes in the wiring that can damage the batteries. It is crucial to use a high-quality, heavy-duty wire to interconnect the batteries in your solar panel battery bank.
Inverter
A solar power inverter converts the direct current (DC) energy produced by the RV solar panels into usable alternating current (AC) power that can run lights, appliances and electronics while your RV is in use. It’s important to size your inverter correctly so that your appliances don’t draw too much power and run your batteries down too quickly, as well as sized appropriately for your peak usage times when you want to run the most demanding appliances like a microwave or air conditioner.
An inverter rated for the maximum output of your panels should be installed close to your battery bank to minimize any power loss between them. The power inverter also needs to be plugged into the battery bank using a high gauge wire to prevent overcharging or discharge, which can shorten your battery life and impact how well your RV solar system performs.
When purchasing an inverter, make sure it is a pure sine wave model to ensure the highest quality of power for your RV. It is also recommended that you have a charge controller installed to help mitigate overcharging or undercharging of your batteries. Most of the time, these are included in a solar kit and are simple to install. Some kits will include a cable entry plate already installed on your roof and predetermined location for mounting the solar controller.
Charge Controller
The charge controller acts like the brain of your solar power system, regulating the DC voltage and current that flows from the panels to your batteries. It also prevents overcharging and helps your batteries maintain an optimal level of charge.
The type of battery you use (flooded, gel, or AGM) and the battery bank’s capacity play a role in determining what type of solar charge controller is needed. It is important to note that lithium iron phosphate (LiFePO4) batteries require a different charging profile than lead acid and may only work with specialized charge controllers.
Generally, Pulse Width Modulation (PWM) is the most economical type of charge controller. However, Maximum Power Point Tracking (MPPT) is a newer technology that can yield up to 20 percent more energy than general PWM controllers.
Once you know the current output of your solar panels, select a controller that can handle this amount of current (measured in amps). Mobile Power Battery A label on the back of every panel should detail its maximum amperage. When wires are connected in parallel, the sum of all panels’ currents should not exceed the charge controller’s max power rating.
Look for a controller that’s UL-certified or has undergone independent standards testing. Avoid cheaply made charge controllers, as they can give off a lot of electrical ‘noise’ and interfere with certain electronics.
