Off-Grid Solar System Components

Off-grid solar systems are very helpful when you live off grid. The off-grid solar system components and batteries are designed quite well and improving all the time. Solar systems are even more popular with those wishing to live off-grid, not tied to the local power companies lines.

My goal with this page is to give you a firm understanding of the components of an off-grid solar system so you have the basic knowledge and understanding when it comes time to purchase products from a sales person you probably don’t know. I have vetted the companies shown on this page and know they are trustworthy and offer quality products.

Every system will be comprised of these basic components and be wired almost the same way.

Basic Off-Grid Solar System Components

• Solar Panels
• Maximum Power Point Tracking Solar Charge Controller (MPPT)
• Battery Management System (BMS)
• Inverter
• Batteries
• Monitor and Control System
• Wiring Diagram

Solar Panels

There are several types of solar panels on the market today. These include: monocrystalline, polycrystalline, thin-film, and concentrating photovoltaic (CPV) solar panels.

Renogy makes great solar panels including flexible, monocrystaline panels that are so light weight you can install them with silicone mounting tape. They can bend up to 240°, are very thin, and durable. Guaranteed for 5 years. Renogy solar panels have many other advancements like bi-facial and folding panels producing up to 320 watts from just one panel.

The Charge Controller

A charge controller is the gate keeper, or regulator, between your solar panels and battery bank. It keeps your batteries safe from over charged, heating up, and averting a bad situation from that. You’ll need only one but it needs to be sized right.

There are two types of charge controllers.

A Pulse Width Modulator (PWM) charge controller is used in basic one battery systems. It turns on and off determined by the needs of the battery.

A Maximum Power Point Tracking Solar Charge Controller (MPPT) is much more sophisticated and, of course, more expensive. It constantly adjusts the voltage coming from the solar panels to the batteries to deliver the most it can depending on what the batteries need and the draw of any load on the system at the moment.

There are several more differences you can delve into on the SunMaster website.

Victron offers a good selection of MPPT charge controllers with varying voltages, amperage ratings, and other features to match the system you are building. Many are Blue-Tooth enabled to send real-time information to your Smartphone or tablet.

Battery Management System

Battery management system (BMS) is electronics used to monitor lithium battery packs to safeguard against unexpected load scenarios. For extreme details of the BMS refer to the Synopses website.

Victron makes several versions of their BMS specific to various types and wiring of lithium batteries. These important devices detect the state of charge and protects against deep discharge and overcharging. From their owners manual: “A configurable pre-alarm warns with a minimum delay of 30 seconds of an imminent shutdown of the loads as a result of an impending low cell voltage. By reacting quickly on the pre-alarm, for example by reducing the load or starting a generator to charge the batteries, the shutting down of the loads can be prevented. The ATC contact is opened to stop charging at high cell voltage or low temperature, while the ATD contact is opened to stop discharging at a low cell voltage. DVCC controls compatible devices via Lynx Smart BMS and a connected GX device. Charging current and voltages are set automatically, thus Bulk, Absorption and Float algorithms are no longer used. Charging or discharging are stopped at low or high cell voltage or low temperature.”

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Off-Grid Solar System Consulting

You can see that with so many variables and options your solar system design is getting complex. Trek Systems (formerly RV Solar Connections) offers guidance and technical support. They will guide you thru an energy audit and help you pick the right products for a successful outcome. They’ll also supply you with a custom wiring diagram for you exact situation.

It pays to connect with a company like trek systems knowing you are getting the right parts and doing a good job of this expensive and important feature of your off-grid build.

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Inverters

The inverter is one of the most important pieces of the complete solar power system. An inverter takes the DC (direct current) from the battery bank and converts it to AC (alternating current) at the proper voltage (110 volts-220 volts) for your equipment to use. Additional filters and other electronics can be used to produce a voltage that varies as a clean, repeating sine wave that can be used without damaging electrical equipment.

Again, there are many types of inverters so it always pays to consult with an expert as to which inverter is right for you.

The Victron MultiPlus 12-Volt 3000VA with 120 amp charger is an industry-leading inverter charger. It has many convenient features packed into one compact unit. Not only does it take up less space, it also keeps wiring simple, ultimately making for a cleaner and easier installation.

If you’re tight on space but need big power, the MultiPlus is perfect for conversion vans as well as RVs. Rated at 3000VA (or 2400 Watts Continuous), it has the power to operate everyday appliances from induction cooktops, refrigerators, tvs, coffee makers, air conditioning units and much more.

In order to program Victron inverter/chargers to work with your particular batteries, you must have an MK3-USB interface, or GX device, such as the Cerbo GX.

Victron Warranty

When you buy Victron components from trek systems they come with a 5 year warranty. You can buy an additional 5 year extended warranty for 10% more.

Combo Units Make Wiring Easier

This All-In-One Solar Inverter/Charger/Controller has everything you need to create a complete solar power system:

• AC Inverter
• Solar Charge Controller
• AC Battery Charger
• Automatic Transfer Switch (if grid power is available)
• Circuit Breakers/ Temperature Protection/ Custom Charge Profiles
• Compatible with many Battery Technologies (Lead Acid, Flooded, AGM, Lithium, LiFePO4

The MPP Solar PIP – 1012LV-MS is ideal for RVs, cabins, and homes with 12v battery power. If your battery runs low, it will switch over to utility power (for on-grid homes) or generator.

 

Batteries for Off-Grid Solar Power System

Batteries are the anchor of any 0ff-grid solar system. An off-grid solar system requires enough battery storage to supply your energy needs using the minimum of generator backup if the sun is not available.

Battery technology is improving everyday. You can get an astounding energy density in a small package. The Dakota battery shown has a capacity of 640 amp hours in a very small space: 27″L x 8.07″W x 10.43″H. Dakota Lithium batteries provide consistent power for all 640 Amp hours. DL LiFePO4 batteries have a flat voltage curve, which means they have a steady power output as the battery discharges. The power output will not dramatically drop like similar sized SLA batteries. You get all the juice down to the last drop. It also has internal heating while charging for use in extreme cold, and CAN bus and NMEA communication. It’s guaranteed for 11 years.

For more on batteries visit this page of our website: Solar Power for Tiny House

Renogy has a good blog on How To Choose The Best Battery For Your Solar System.

Monitor and Control Systems

You will need a monitor and control system compatible with the other equipment in your solar system. This gives an instant overview of your system and allows you to adjust settings in the blink of an eye.

Many of these systems have an app for your phone or tablet if you get the optional wireless interface module. I recommend staying with the same brand of solar equipment so you are assured it will work together. All of the companies mentioned on this page have a full line of good solar system parts.

Renogy makes a great control/monitoring system called One Core. They designed Renogy ONE to make living off-the-grid comfortable and secure. Rather than having to buy multiple monitors and shunts, Renogy ONE acts as the brains of your off-grid power with a single touch-screen display that provides total smart energy monitoring and control. You get real-time data and intuitive displays of all your connected devices and appliances.
With Renogy ONE, you no longer have to monitor the performance of your LiFePO4 batteries, inverters, or smart battery chargers on separate screens. Renogy ONE gathers all the performance data you need and sends it to you wherever you are.

Victron GX Touch 70 Flush

Another good monitoring system is the Victron  GX Touch 70 a display accessory for our Cerbo GX (mentioned above). It works seamlessly with all the Victron components.

The seven inch touch screen display gives an instant overview of your system and allows to adjust settings in the blink of an eye. Simply connected to the Cerbo GX with one cable, the super slim waterproof design, top-mountable setup and simple installation bring a lot of flexibility when creating a crisp and clean dashboard.

The GX Touch is a companion to the Cerbo GX. This communication-center allows you to always have perfect control over your system from wherever you are and maximizes its performance. Simply connect through our Victron Remote Management (VRM) portal, or access directly, using the GX Touch, an MFD or our VictronConnect App thanks to its built-in WiFi Access Point.

Additional products you’ll need:

 

For the control systems and any component interconnects you’ll need to make RJ-45 modular connections on Cat-6 network cable.

Refer to this page for details: Wiring Your Tiny Home for TV and Network

Solar Panel Connector

Solar systems use a connector called an MC4. You will need to be able to make these to the length you need for your install. The 60pc solar panel connector kit shown here includes the tools needed to make professional connections and 30 connectors.

 

Heavy Gauge Solid Copper Wire

You’ll also need some very heavy gauge pure copper wire. The thickness of the wire you will need depends on the voltage of your system. The lower the voltage the thicker the wire must be because the amperage will be higher. 

 

Battery Cable Lug Crimping Tool Kit

Everything you need to make professional quality connections in your solar system. This kit includes the proper tools, heat shrink tubing, and solid copper lugs for best connection.

Battery Disconnect Switch

 

A battery disconnect switch is an important safety feature of any solar system.

A battery disconnect switch allows you to easily isolate the battery power from the rest of the electrical system. This prevents drain from parasitic voltages during non-use and offer extra safety when servicing the solar system.

 

Off-Grid Solar Power Wiring Diagram

A wiring diagram is essential to create an off-grid solar system. Look at all the detail in this schematic that we haven’t touched on. Every detail is shown.

An off-grid solar power wiring diagram will save you time and money. It will prevent you from making mistakes, and allow you to create a professional system even with basic skills.

Trek Systems, formerly RV Solar Connections, was founded with their main product being custom solar system wiring diagrams.

First they discuss your specific energy needs and expectations. Then we determine the appropriate size battery bank, solar array, and other aspects of the system — additional charge sources, sensors & monitoring/control equipment. These first couple steps are included at no charge with their preliminary system design service. Start with the Trek Energy Audit Calculator to determine system sizing.

Custom wiring diagrams are available by request and include the following:

• All primary components and how these fit together (batteries, inverters, chargers, monitoring and control, etc.)
• Appropriate wire size and circuit protection for every circuit
• Any other accessories or important details

Buying An Off-Grid Solar System Kit Ensures Success

Even a basic off-grid solar system can be complex. Buying a complete kit ensures that you get every little part you need along with the assurance that it will all work together.

At ShopSolar (formerly Shop Solar Kits™), they’re cutting through the solar industry’s overpriced nonsense to make energy independence simple, transparent and affordable. Not only do you get a package price, you also get a lifetime of technical support.

Whether you need an off-grid solar system for your campervan, skoolie, RV, or homestead, Shop Solar can match you with the best products.

 

 

Additional Sources Of Off-Grid Solar System Information

From all the information above you can see why most of us are “in the weeds” when it comes to creating a solid off-grid solar system. We need help. The suppliers of these parts stand ready to be of assistance with training, wiring diagrams, and professional installation services.

Shop Solar offer a very good video course about building a solar system. Learn how to size, setup and maintain your own solar power system in less than hour! This Ultimate Solar Mini Course will save you hundreds of hours of research with step-by-step, easy to understand online videos that walk you through everything you need to know about solar power. Click on image to learn more.

 

 

Energy System Installation Network

 

trek systems maintains a nationwide network of trained and vetted installation professionals. Many of whom have taken their ridged train course.

Consulting Service

If you are ready to take the lead on your own off-grid solar project RV Solar consulting services are the middle ground between doing it solo and hiring a professional installation team.

 

 

 

Off-Grid Solar System Examples

Here’s a great YouTube® video on a solar system in an RV capable of running the air conditioners all day.

I count 10 solar panels on the roof but the real heart of the system is 12 Battle Born, 100 Ah, 12 volt, LiFePO4 Batteries.

Each battery weighs 31 lbs. and costs $995.00 each. In addition, there are two Victron MultiPlus 3000 watt inverters that cost $1,233.00* each,  and a solar charge controller. A 24 to 12 volt step down transformer to run the 12 volts devices completes the system.

Without doing the math I can see that this is pretty expensive and takes a pretty large roof to hold all the solar panels but it does work so it can be done.

 

Using A Portable Power Station

A super easy way to add a solar system to your RV or tiny home is to start with a portable power station and use their recommended solar panels to charge it. A portable power station contains a battery, charge controller, BMS, and all other components needed to supply 110 volts for your use.

I use an ANKER, Solix F2000 Portable Power System in my RV. The Shore power cord plugs right in to it’s 30 amp outlet and I’m done. It might look a bit ugly but I strapped it in good so it wouldn’t be a danger if I stopped fast. I can’t run the air conditioner but I can use the microwave oven and run the refrigerator, plus charge my devices.

To recharge I use their matching 4oo watt solar panel. It comes with over 18′ of cable so I can get out from under the shade and into direct sun for optimum sun absorption. They also have a tilting stand to get them aimed directly at the sun. It’s more versatile than having fixed solar panels on the roof.

Because I camp at high elevations I don’t miss using the air conditioner so this works perfect for me.

 

Other pages of the Tiny Life Consulting website you be interested in:

Solar Power for Tiny House

Running RV Appliances Like Air Conditioners Off-Grid

Portable Power Centers How To Choose

Generators or Portable Power Centers: Which One is Right for You?

Portable Inverter Generator Comparison

Off-Grid Resources and Information