Installing a Solar Panel System in a RV and Trailer

A solar panel starter kit is an excellent way to have free energy when traveling or living in an RV, trailer, or cabin. There is no need to drag around a gas generator anymore. These kits are easy to install and require limited knowledge of solar technology. They are great for charging 12-volt batteries that will provide power for many applications like lighting, electronics, TV, and small appliances. These types of panels can also be set up in series to provide more power. Solar panel kits are an excellent way to get started using solar energy.

How a Solar Panel System Works

If you look at the diagram above, you can see how a basic solar panel system works. The solar panel (cells) takes sunlight and converts them into direct current (DC), which is then sent to a charge controller and stored into batteries for later consumption. Since the power is stored as DC and all of our household devices run on AC, it needs to be converted using a power inverter. Standard household AC plugs can then be plugged into the inverter.

Choosing a Solar Panel Starter Kit

Several types of solar panel starter kits can get you off the grid. Depending on your requirements, you may only need one solar panel. You will need to determine your average amp usage throughout the day by observing your electrical usage. You can use the energy calculator at energy.gov to calculate your consumption. If you want more charging power (wattage), then more solar panels will be required. You can start with a basic solar panel starter kit and always add more panels if needed. Just make sure you leave some room for expansion.

Renogy 200 Watt 12 Volt Monocrystalline Solar Starter Kit

Renogy makes a nice solar panel starter kit. They are high output and efficiency panels for the price. Renogy solar kits are also easy to install and come with a complete mounting kit and setup manual. They have an active forum page to help with any installation and technical issues. You can also check out their YouTube channel for helpful install and troubleshooting videos. This is an excellent kit that should cover most of your electrical needs. You will need to purchase batteries and a 12-volt power converter separately. The solar kit can also be expanded to 400 watts if more output is needed. You can see more solar panel kits here.

Kit Contains:

• 2 Renogy 100 watt 12-volt Mono-crystalline Solar panels
• Adventurer Li 30A PWM flush mount charge controller
• 1 30Ft 10AWG MC4 adaptor kit
• 1 16Ft 10AWG tray cable
• 1 pair of branch connectors
• 1 bt-1 Bluetooth module
• 1 Renogy cable entry housing

eBay:

Renogy 200 Watt 12 Volt Monocrystalline Solar Starter Kit

Amazon:

Renogy 200 Watt 12 Volt Monocrystalline Solar Starter Kit

Placing Your Solar Panels

Solar panel placement is key to getting the most out of your panels. You should try to have them mounted somewhere they will receive full sun, generally, on the roof with a tilting mount. This will allow you to move the panels into the best position to track the sun. Sun intensity will vary throughout the year, depending on your location.

Solar Charge Controller

A good quality solar charge controller can make a difference in how well your solar panels charge your batteries. Solar controllers regulate the voltage output from the solar panel and prevent cells from being overcharged. Most batteries need around 14 to 14.5 volts to get fully charged. If the sun is shining and the panels are still producing energy, the charge controller will protect the battery system. Most solar kits come with a basic one, but you may want to consider upgrading to a more efficient controller. If you plan on expanding to more panels, this is a good option.

MPPT vs. PWM Solar Charge Controller

PWN controllers act like a switch connected to your batteries. They are suitable for regulating smaller load capacities and have an efficiency rating of about 80%. These controllers will prevent you from running several panels in series due to its capabilities. If you have one or two panels, this should work fine.

MPPT controllers can regulate high voltages and have an efficiency rating in the 90% range. This will allow you to run your panels in series. They harvest the maximum power of your solar array. They can also save on cabling costs by increasing your voltage, thus requiring lower gauge cable.

Battery Requirements

The number of batteries required depends on your load. You need to decide what you are planning to run off your batteries and how much load you require. A Kill A Watt meter can help you determine the amount of power output you need. Make sure you do not discharge your batteries below their 50% capacity. This will ensure long battery life. Peak solar energy happens between midday and peak consumption occurs in the evenings. Generally, nighttime is when lights, appliances, and electronics are in use. To reliably power your dwelling, a battery bank must charge in the few hours of intense sunlight and discharge throughout the evening and night. Generally, one or two good-quality 12v deep cycle batteries should suffice for most RV set-ups. Higher-end RVs will already have existing batteries installed. So this step will not be needed. You can install the solar panels and charge controller to your existing converter breaker charge panel.

Here is the formula to determine how many batteries you may require.

Backup Time = Battery AH x 12V x N x Efficiency of Battery / Load in Watts Table: Battery AH = Ampere Hour Capacity of Battery N = Number of 12 V Batteries needed Efficiency of Battery = Generally it is 0.8 A formula for how much your batteries can store: X (Battery size in AH) x Y (Battery Voltage) = Z (Power available in watt-hours) You can check out the forums at Solar Power Talk to find out more about battery calculations.

This video explains how much battery power you will need:

Power Inverter

Your last step is to buy a power inverter. Depending on your RV, you may already be equipped to handle the conversion. Inverters are designed to convert a 12 volt DC battery power to 120 volt AC household power. This allows an electronic device to be plugged in and operated just as if it were being used in your home. They come in different capacity types depending on your needs. They are wired to your battery system.

OSIAS 2000W Power Inverter 3 US Outlets 3.1A Dual USB Ports

The OSIAS 2000W Power Inverter allows you to run many devices at once, like a blender, refrigerator, tablet, and TV. This inverter can be wired right into your battery bank. Depending on your electrical needs this inverter should satisfy all of them.

Specifications:

• Provides 2000W Continuous DC to AC Power Output
• Peak Power Up to 4000W Surge Capacity
• Converts 12V DC Battery Power to Standard 110V AC
• 3 AC Outlets and 2.1A USB Port Deliver 2000W Continuous Power
• Smart Digital Display
• Cooling Fan
• Audible Undervoltage Alarm
• LED Indicator
• Built-in 14 x 25A Slip Fuse to Protect Against Over Voltage

eBay:

OSIAS 2000W Power Inverter

Amazon:

OSIAS 2000W Power Inverter

Installation Tips

If you are lucky, some RV’s already come pre-wired with the cabling needed for adding solar panels. This can be a big time saver. If not, then you have to snake the cabling throughout the RV. This can take some time and patience to get your cabling in the right areas. Depending on the type of RV, your wiring application will vary.

Solar Panels

The solar panels can generally be mounted on the roof. Just make sure you leave enough room to walk around and get to the parts of your RV roof for maintenance. They should be placed where nothing will cause shadowing on the panels. First, measure out the size and distance of the panels and dry-fit them to see how they look. Also, layout all of the cablings first before fastening and make sure you have enough to reach your destination. The panels screw into the roof with the brackets that are supplied with the starter kit or tilt kit. If you plan on using a tilt kit make sure to leave enough cable slack to allow for the panels to tilt. You should use a good lap sealant to seal up the areas around the screw holes to make a watertight seal. The best way to run your solar panel cables into the RV is through a roof or refrigerator vent.

Cabling

Running your own cabling will take some time to figure out. Your RV may have existing cables snaked for other applications. If applicable try to snake the solar and power cables along those routes. You will need a cable snake to make this process easier. Try to run heavier 6 gauge wire to reduce loss along the line. A general rule of thumb is the thinner the wire, the more energy is lost. Also the longer the cable runs from the solar panels to the batteries will cause some energy loss. To secure your cables, zip ties work very well. Make sure to leave enough slack on your runs for securing the cables and add additional fuses that may be required. The chart below shows the gauge cable needed for distance.

Control Center

The main control area can be placed in a utility closet/storage or placed with the existing power panel. This should house your charge controller and meters. Consider installing a power switch that will enable you to switch off the solar system. This can be useful for service issues and maintenance like replacing a battery. This process should take some planning. Each RV setup is different. Do some research about your RV and investigate the best spots to place your equipment.

Conclusion

Just be patient and plan ahead. Think out the process before installing anything and when in doubt ask for help. A solar panel starter kit is much more affordable today than they use to be. They do require a bit of technical know-how to install, but if you are a handy person you should have no problem tackling it. In the long run, it can save money and make you more self-sufficient.