The solar power system has been one of the most common energy sources for camper vans and other recreational vehicles. They are sustainable, the cost of maintenance is inexpensive, and they do not require regular charging from an energy post. It’s the perfect energy source for motorhome-owners as this energy is capable of producing electricity everywhere. Once installed in your RV, you do not have to worry about getting fuel for your generators or where to charge the batteries.
The whole process of setting up a solar power system in your recreational vehicle can be overwhelming. But we got you covered! This article will discuss how to determine your average wattage consumption, the process of setting up the components of a solar power system, the proper storage, and more.
The Power Equation: Solar Energy Needs for Your RV
Solar energy works through the solar panels by allowing particles of light, also known as photos, to knock electrons free from atoms, which, as a result, generates a flow of electricity. The panel’s photovoltaic cells convert the energy arising from the sunlight into direct current. This direct current electricity is converted to alternating current by the inverter. The alternating current is what is typically being used as a source of electricity. It sends power to the lights and appliances in your recreational vehicle.
Power Stored: Energy Generated And Stored To Your Batteries
The ultimate question lies in the number of watts your recreational vehicle needs on a regular basis. The number of solar panels you need depends on the following factors:
- The kind of solar panel you are going to purchase
- The average daily energy consumption of your motorhome, and
- The capacity of the batteries you will use.
Wattage: Kinds of Solar Panels To Choose From
Solar panels generate power by absorbing the sun’s light and convert it into heat or electricity. They are measured in watts. There are several different sizes for solar panels that are available in the market. Some of the available are 360, 335, 300, 265, 225, 200, 170, and 100-watt solar panels.
However, the number of panels does not matter. What matters is the total wattage of all your solar panels. This is determined by multiplying each solar panel’s wattage with the total number of solar panels you own. For example, if you have four 100-watt solar panels, you have a total of 400-watt solar array.
Battery Capacity: How it Affects the Number of Panels You Will Need
The next factor to consider is the battery capacity. You need to determine your batteries’ usable capacity to ascertain the number of solar panels you will need. The solar panels are not running your appliances and electrical devices. They are run by the electricity stored in your batteries. The number and type of your batteries must be based on your specific electrical demands. On the other hand, the number of your solar panels rests on the capacity of your batteries.
Your batteries’ usable amp-hours depend on whether they are made of lithium, AGM, or Lead Acid. The nominal capacity of a lithium-powered battery is 100%, while AGM and Lead Acid batteries have a nominal capacity of 50%. If you have three 100 AH lithium-powered batteries, your motorhome’s usable amp-hours are equal to 300 AH. However, if you have three 100 AH AGM or Lead Acid batteries, the total usable amp-hours is only 150 AH.
Now let’s do a little math to determine how many panels you need for your recreational vehicle. A battery with 100 Amp Hours of usable energy holds about 1280 watts of power. That is calculated by multiplying the usable power by 12.8, which is 100 AH multiplied by 12.8 volts to obtain 1280 watts of power.
The average hours of sunlight per day in the United States are around 6 hours. To charge a 100 AH battery, which holds about 1280 watts of power, simply divide the number of watts by the average hours of sunlight per day in your city, state, or country. In this example, divide 1280 watts over 6 hours. We will get 213 watts. Hence, for every battery with 100 AH usable power, you will need 213 watts solar panel to charge the same. But a 200-watt solar panel can adequately do the work. However, having more solar panels will charge the battery faster and better in cloudy or low light situations. It compensates for cloudy and rainy days.
To determine the number of batteries you will need, you have to assess your recreational vehicle’s average daily energy consumption. Once you know the total wattage you need, you can then divide the total wattage up into the individual solar panels you plan to acquire.
Average Daily Energy Consumption of your Motorhome
The number of solar panels you will purchase will be based on your batteries’ total usable amp-hours. The solar panels charge the batteries, which in turn charge or power your appliances. So the number of batteries you will need will be based on your average regular electricity consumption. To determine your total wattage consumption, you can use either the camping or counting method.
Power Used: Amp-hours per Day
One of the most critical matters to determine before embarking into solar energy is the amount of electricity needed and usually consumed by your recreational vehicle. It is essential to know how much energy your motorhome needs regularly. This will allow you to plaster every inch of your RV roof with the necessary and useful number of solar panels.
It is a waste of money to have nothing to store all the extra energy your panels produce when your battery runs full. Furthermore, it is also risky to run out of energy when you have underestimated your motorhome’s electricity needs. Adding batteries, having battery banks, or using generators can be the solution for excess or lack of electricity. However, having the right number of panels for your energy needs is the ultimate solution to these problems.
So how do you determine the battery capacity your motorhome needs? To answer this, you will need to calculate how much energy you consume daily. There are two ways to determine the same. You can manually compute or go on a camping trip and determine the average amount of energy you used on that camping.
The Camping Test
The best way to determine how much energy your recreational vehicle will consume is actually to go camping. Multiple camping trips are even better as the number of samples increases, the more accurate and precise your estimate will be. Further, camping is way more fun than computing on a spreadsheet using the other method.
To determine your motorhome’s average electricity needs, first, settle out in the wilds for a couple of days. Just camp normally. Use your recreational vehicle and the appliances therein as normally as you do without conserving or using more energy. Using a battery monitor, track your battery level. Do a little math to determine the amount of energy you consume on a daily basis. For example, if your 200 amp-hour lead-acid batteries are at 50% after camping for two days, you consumed about 50 amp-hours a day. You can make more camping trips to determine if the energy consumption on your first attempts is similar to your other camping trips. You can add them up and get the average power consumption of your recreational vehicle.
The Counting Test
The counting test is employed by simply adding up the total watts per day of each appliance in your recreational vehicle based on the suggested average energy consumption for every device and the estimated time the camper uses each of them daily. For example, if you use your television for about two hours a day and it consumes 90 watts per hour, you will have to allocate 180 watts for your TV, and so on for other appliances.
This is too much math for an average individual since the method includes estimating the number of hours an appliance is used per day and determining the watts consumption of such appliance per hour. Additionally, most recreational vehicles have several appliances. So, you will need to pull out information from your home gadgets, make estimates, and employ basic math skills to do this test.
The counting test is not an advisable method. It does not always provide a precise estimate of the camper’s energy needs. It involves several estimates which may or may not be close to the real figures. Furthermore, the suggested energy consumption from the product description of the appliances may not be true in certain circumstances. Hence, this method is not really reliable and accurate. If you can employ the camping method, go for it! The camping test is convenient and provides a reasonable estimate of your actual electricity needs.
The Setup: From Tools to Final Steps
After determining your average daily energy needs, you have to learn how to set up your solar power system. The essential parts of the solar setup that you need are the solar panels, charge controller, batteries, and the inverter.
Solar Panels
The solar panels are devices used to absorb the sun’s light or rays and convert them into heat and electricity. It is a collection of photovoltaic or solar cells, which are used to generate electricity through the process called the photovoltaic effect. The panels generate electricity by allowing the sunlight to knock off the electrons in their atoms. Its primary purpose is to absorb the rays of the sun and convert them into heat or energy.
There are two main types of solar panels, namely monocrystalline and polycrystalline. The main difference between the two is efficiency. A monocrystalline is generally more expensive than polycrystalline. However, the former typically have bigger watt capacity than the polycrystalline even with the same size and dimension. If you have limited room on your roof, go for monocrystalline panels as they generate greater electricity from the sun compared to polycrystalline. However, if you are tight on your budget and your motorhome’s roof has enough space, go for polycrystalline panels.
Charge Controller
The charge controller ensures that the battery does not overcharge or discharge too much energy under any circumstances, including extreme changes in weather conditions. It controls the working systems of the solar lights to protect the battery charge. It may also include sound, temperature compensation, time controller, light controller, reverse polarity protection, lightning protection, and AC transfer switches. These added features ensure that the sensitive back-up works properly even when an outage occurs.
Batteries
The battery of the solar setup is often housed within a plastic or metal case. Inside are the electrodes where the chemical reactions occur. It is the part of the solar setup that stores the solar panel’s energy and provides the power needed by your recreational vehicle. The batteries incorporated in the solar setup often use gel electrolyte technology with high performance in deep charging, which allows it to be used in extreme ranges of temperature.
There are two types of batteries commonly used for recreational vehicles. They are lithium and absorbed glass mat (AGM) batteries. The third type, Lead Acid, is not often used for motorhomes. But it has the same nominal capacity with AGM batteries. Lithium batteries have a nominal capacity of 100%. They are significantly more expensive up front, but they are cheaper in the long run since their maintenance is not costly, and they provide bigger storage capacity for the energy generated by your solar panels. They are lighter and more powerful than AGM batteries. Hence, lithium batteries are the go-to batteries for solar setup.
Inverter-Charger Combo Unit
The basic function of inverters is to convert the direct current or DC power generated by the solar panels to alternating current or AC power that is used to charge your gadgets and power your appliances.
There are three types of inverters, namely square wave, modified sine wave, and pure sine wave. The first two types, square wave, and modified sine wave, are not advisable for solar setup as they have the inherent risk of damaging other equipment. The modified sine wave inverter can work for ordinary equipment and appliances such as televisions, tablets, and cameras but may not operate well with precise and delicate equipment that contain electronics or other devices which require choppy waves. The preferred and commonly used inverter is the pure sine wave. Pure sine wave inverter guarantees to produce a cleaner output for any piece of device or equipment connected to and powered by it.
Mounting or Racking
Also known as racking, the photovoltaic mounting system is not the main component of a solar power system installation. But it is an essential part of the solar panel. It securely attaches your solar panels to the roof of your recreational vehicle. The solar racking system is used to fix the solar panels safely into various surfaces, such as building facades, ground, and roofs.
The Tools
After determining the main components of your motorhome’s solar system, you need to prepare the tools to mount, attach, and connect these components. For the whole setup from solar panels to the inverter, the tools you will need are:
- Entry gland
- Positive and negative wires
- Butyl tapes
- Electric screw gun
- Screws
- One inch hole saw
- Roof sealant
- Painters tape
- Electric drill
- MC4 connectors
- MC4 fuse
- MC4 wire campers.
- 80/20 aluminum extrusion
- 80/20 corner brackets
- And a two and a half millimeter hex key
The Solar Arrays: From Mapping to Mounting
To install the solar panels, the first step is to map the roof of your recreational vehicle. Create a design and plan the placement of the panels to the roof of your motorhome. The panels must be at least one or two inches away from each other. Measure the distance of the panels, the placement of the wires, and the slots into which the wires will go through. You can draw the template over your roof so you can have a better view of the setup.
Next, drill a hole on the exact location where the wires will go through using an electric drill or electric screw gun. Assemble the wires and secure it to the roof using butyl tape, screws, and roof sealant. Then attach the mountain system to the solar panels. The process is a case to case basis. The solar panels come with an instruction manual regarding the proper attachment procedure of the mountain feet to the panels.
After attaching the mountain feet to the panels, mark the location of the mountain feet to the roof of your motorhome. Drill the hole using the marks as templates. Then clean the area where the panels will sit using alcohol or other cleaning agents. Fill the screw holes with epoxy and insert the anchors.
Next, apply foam tape to the mounting feet. Then place butyl tape around the perimeter of the mountain feet. Place the solar panels back into the place where you made markings as a template of the screw holes. Screw the panels through the anchors. Then liberally coat the edges of the mountain feet and screw heads with roof sealant. Do all the steps for every solar panel you have.
The Storage: Batteries, Inverter, and Controller
The batteries, inverter, and charge controller must be all installed inside your RV. This means you will have to allocate a little space inside your RV as part of your motorhome’s solar setup. You can make a cage specifically designed to hold all these three items. Alternatively, you can mount the charge controller on a flat surface near the batteries and inverter and then place the other two components in one aluminum cage that will hold both of them together.
The inverter will sit on top of the aluminum cage. The charge controller may be placed on the batteries’ side, mounted on the wall or floor. The voltage losses or decreases as it travels through the wires. It is advisable that the solar controller is placed as close as possible to the batteries. This will reduce the length of the wires which the electricity will have to go through before being stored in the batteries.
Make sure that the three are securely placed in one enclosed and dry area of your recreational vehicle. They can be kept at the bottom of the kitchen sink or hidden in a small compartment behind the couch. Wherever you choose to keep them, make sure that the desired location is dry and clean.
The Aluminum Cage For Your Batteries and Inverter
The aluminum cage looks like a skeletal cage that only holds the perimeter of the batteries. To make the cage, the first step is to cut the aluminum extrusions, or a metal strip made of aluminum, according to the size that will fit all your batteries. Make two cuts for each side. One that will hold the bottom and another that will sit on top.
As for the poles that will hold the base and top, cut four equal lengths of aluminum extrusions. These will hold the base and the bottom of your cage. Attach each side altogether using the corner brackets to create a skeletal cage. After building the aluminum cage, securely mount the cage inside your motorhome using bolts and nuts.
The Wiring System
The wires transfer the energy generated by the solar panels to the solar controller, and finally to the batteries. It is the most critical component of your solar setup. The more time electricity travels through the wires, the more voltage is lost. You lose some of the energy generated due to the wires it has to pass through.
Hence, you have to specifically design the placement of the parts composing your solar setup in order to have the least possible length of wires. Nevertheless, the placement must not jeopardize the design or layout of your motorhome. But another way of mitigating the loss of energy due to long wires is the use of large-sized gauge wirings. They allow a faster and smoother flow of the voltage. Unlike the use of wires with small gauge diameter, and cheap wires that do not use copper, wires with bigger gauge diameter do not inhibit the flow of energy generated by your solar panels.
Size of Gauge Wire You Will Need
The size of the gauge wire has an impact on the performance of the entire solar power system of your motorhome. There are instances in which wires with larger gauge sizes are preferred. There are also cases in which the smaller or average gauge sizes work better. You have to take into consideration some facts before choosing your wires.
First, the larger the wire’s gauge size, the more expensive it is per foot or meter. One reason for this is that copper is often incorporated in large wirings, and copper is not cheap. It is one of the expensive metals used for wirings and other construction materials.
Second, the larger the gauge size of the wire, the harder it is to install. This is because thick wires take up more space than thinner wires. Furthermore, it is more difficult to shove these wires through the holes due to its size.
The third consideration is the weight of the wire. It is a rule of thumb that wires with a larger diameter are heavier compared to those with lesser diameter. It is something that motorhome-owners must consider. If you fear that the weight is too much for your recreational vehicle, then go for thinner wires!
Care and Maintenance: A Guide to a Well-Kept Solar-Powered RV
Maintenance and Monitoring
Generally, the solar power system of your recreational vehicle does not require costly maintenance. There is little maintenance to be employed on a well-designed solar power system. The components of a solar setup have no moving parts that might wear out. Furthermore, they do not consume fuel, and they do not have filters that require regular replacements. But there are common little maintenance tasks often employed by motorhome-owners. These are cleaning, monitoring, and occasional replacements of the main components.
Replacement
The solar panels can last for decades as long as you keep them clean, free of snow, debris, and other objects. The general rule of thumb in the solar industry is that solar panels last for about 25 to 30 years. These figures do not mean that the panels will stop generating electricity after 25 years. What this statement implies is that the production of energy has declined by a significant amount. The efficiency of solar panels will lessen as the years pass. After decades of use, you will realize that they are no longer efficiently performing as they should be and that the panels will necessarily require replacements.
As for batteries, the typical range for a solar battery’s useful lifespan is around five to fifteen years. If you install a solar battery today, you will have to replace it at least once to match the lifespan of your solar power system, which is about 25 to 30 years. The lifespan of the batteries varies with their usage, brand, and type. AGM batteries generally have a lesser lifespan than lithium-powered batteries. So if you opt for AGM batteries because they are cheaper upfront, expect more cash outlays in the future due to necessary replacements.
Inverters will likely need replacement a few times throughout the lifespan of the solar panels. The lifetime of solar inverters is about 10 to 15 years. Unlike solar panels, the efficiency of inverters does not gradually dwindle. It will function up to its last moment. Then it will simply stop working, which is the obvious sign that it needs to be replaced. But the life expectancy of an inverter depends on its environment. High temperature has an adverse effect on the lifetime of inverters. Hence, preferably install your inverter in a cool and well-ventilated area inside your motorhome.
A charge controller has a lifespan of about 15 years. Like inverters, you might have to change the charge controller at least once during your RV’s photovoltaic system’s lifespan. However, the controller’s lifespan may be lessened if you did not choose the proper controller for your system. They say, “do it once, but do it right.” Selecting the right charge controller for your solar power system will reduce, if not eliminate, the problems arising from having the wrong one. Not only will it cause your solar power system to underperform or not work at all. It can also damage other main components. Hence, choose the right charge controller to reduce the risk of having these problems.
Solar Panels: Verification Through Monitoring
Aside from their physical appearance, another way to know if the solar panels need to be cleaned is by comparing the solar output. Has the output decreased due to grimy solar panels? A less than normal output level is a sign that the panels require extensive cleaning. According to the Photovoltaic Guide released by the German section of International Solar Energy Society, or the DGS eV, on average, an unclean solar panel generates about two to seven percent less energy than a clean solar panel. But, a sharp drop in output level is more indicative of a technical problem in the solar panels. Hence, if the efficiency level drops by more than 10 percent, you should have your solar power system serviced by a professional.
You can also install a monitoring system to keep an eye on the performance of your solar panels. When the performance goes down, maintenance is likely required. Most of these monitoring systems need to be installed professionally with the purchase of a monthly subscription fee. But since they come with certain advantages, the subscription fee might be worth it.
Cleaning
Cleaning the panels and other components, keeping dirt, debris, and filth away, and checking the mounts and fasteners’ tightness are basic maintenance work to keep the well-being of your solar power system. All you have to do is regularly clean them with cleaners that are non-abrasive and make sure the fasteners and mounts are tight. Movements, vibration, contraction, and expansion due to temperature changes, can loosen the hardware’s mounting. It’s advisable to conduct regular checks on these mounts.
The Optimal Period to Clean Your Solar Panels
Generally, there is no optimal period to clean your RV’s solar panels. However, when it comes to climate and weather changes, you have to note the winter and autumn seasons. The snow or leaves falling on your panels might get in the way from the sun’s rays. Additionally, heavy rains carry with them water and little dust particles that can accumulate on your solar panels. You might want to consider checking your panels every time strong winds blow or heavy rains fall.
There is also no specific time of the day in which solar panels must be cleaned. But, if you do not want to interfere with your solar panels’ output, clean them at dusk or dawn when the panels are no longer warm.
Solar Panels Cleaning Kit
The solar panel cleaning kit works similar to what most of us use to clean our cars and other household items. However, this one is specially designed for solar panels. The solar panel cleaning kit you will purchase must contain a liquid soap, a small brush, a wiper, and, in some cases, a brush with a long handle.
Energy Saving Tips for Motorhome-Owners
One thing that helps extend the lifespan of your RV’s solar power system is not to overwork all its components. Here are some of the energy-saving tips you can practice or employ while boondocking to avoid this.
- Use LED lights or bulbs. These lights perform similar to other kinds of lights. However, they are energy efficient and sustainable. Furthermore, it feels fulfilling to cut your expenses and carbon footprint at the same time.
- Unplug your electronics and appliances when they are not in use. On average, although they are not in use, they absorb up to 25% of the electricity they regularly consume if they were turned on.
- Adjust your lifestyle and daily routine. Sleep at night, work on broad daylight. Read during the daytime when the sun is up. You do not have to turn on a light or lamp to read in broad daylight.
- If you have an extra budget, replace older televisions with LED flat-screen TVs. They are more efficient and use less voltage. Plus, they consume less space in your recreational vehicle.
- Lessen your shower time. We all enjoy a good karaoke moment in the shower. But, it is energy-saving if you do not do this all the time.
- Park under the shade of the trees and use RV awnings to keep yourself cool. This way, you do not have to turn on your air conditioning and electric fans.
Conclusion
The solar power system is the perfect energy source for recreational vehicles. It can generate electricity everywhere without being connected to an electric post and without the need for fuel. It is sustainable, and the cost of maintenance is inexpensive. The installation and the learning process may be overwhelming and complicated for beginners. But it is worth all the sweat and headache once the entire solar power system is installed in your motorhome.
