Set up solar panels for your solar generator

Connecting your solar generator to one or more solar panels is not difficult, but can be intimidating for those inexperienced. Luckily, you don’t have to be a licensed electrician to wire solar panels for an off-grid, home-built solar power station. Here are the different ways to connect your generator to a solar power source.

Wiring a single solar panel to a solar generator

For most small solar powered generator setups, solar panel wiring is extremely easy. Connecting a solar panel (or several small panels packaged as one unit) to a solar generator is as easy as plugging your TV into a wall.

For most standard setups, it’s extremely easy to connect your solar panels and solar array using an MC4 (sometimes spelled MC-4) cable. Plug opposite connectors into the panels and generator, and voila, you’re now running a small off-grid power station.

Of course, like a battery, solar panels have a positive and a negative pole. Generally (like your car battery) solar wiring is color coded, meaning positive is red and negative is black. It is important to connect the correct terminals to avoid damage to the system.

Solar modules in series connection vs. parallel connection for solar generators

For a little extra power, many people connect multiple solar panels together to maximize the charging speed of their generator’s battery. There are two ways to connect multiple solar panels: series and parallel connections.

Here the solar panels are essentially connected as one large panel. Series connections are the simplest way of wiring solar modules together. In a series connection, all solar modules must have the same voltage and current and be connected with a uniform cable cross-section.

A series connection is achieved by connecting the solar generator to the positive pole of the first panel and the negative pole of the last panel. In between, connect all the plus and minus poles of each adjacent panel. To calculate the total input levels of your solar array, you can add the panel wattages and voltages together, keeping the total amperage at the level of a single panel. You need to figure out series vs parallel.

When connected in series, solar energy follows the adage that a chain is only as strong as its “weakest link”. Series connected solar panels are aligned in a continuous, closed loop that requires current to flow in one direction through the system before it gets to your generator. So if one solar panel failed and braked, the entire series would stop generating electricity.

Solar modules connected in parallel

The difference here is that each module can generate electricity as its own separate entity. In a parallel circuit, power can flow directly from each panel to your solar generator.

To wire a parallel circuit, you must connect all the positive and negative terminals of the module together. Generally, an MC4 “branch plug” is used to connect the positive or negative input of a generator to the output of multiple modules.

Here the amperage of the entire off grid solar system can be determined as well as the wattage. For each measurement, simply add up the individual solar panel ratings to get the total amperage or system power. The difference is that the total system voltage is equal to the ratings of the individual modules.

Solar panel series connection vs. parallel connection (advantages and disadvantages)

For solar panels connected in series, the main advantages are as follows:

Less wiring

Low Amperage (Current)

Low power losses with long wiring

With this in mind, it is important to understand that series connected solar panels are only limited to the output of the lowest panel. If your panels are vehicle mounted or receive partial shade throughout the day, daisy chaining is not ideal. In addition, connecting too many modules in series can overload the input voltage of your solar generator.

Alternatively, consider the benefits of connecting solar panels in parallel:

The panels work individually (ideal for partially shaded or mobile systems)

Low overall system voltage

Protected against malfunctions of individual panels

Here it becomes clear that parallel connections are best suited for cases where the solar panel receive different amounts of sunlight. However, most large residential complexes are connected in series. This is mainly done to prevent wiring costs from escalating, while the panels are usually arranged and installed to receive the same amount of sunlight per day. Of course, parallel connections for solar generator setups are more popular for smaller DIY systems trying to get every bit of electricity out of the sun.

Series AND parallel connections (combination) of solar modules

Okay, ready to get a little more complicated? If you are looking for the maximum amount of solar charge on a van, RV then you may want to consider wiring your solar panels in a series and parallel configuration. By combining these two methods, you are able to generate the most electricity in environments with varying levels of sunlight without overloading your system’s amperage. For most people, a series and parallel connection is worth the extra cost of wiring.

Above is the simplest version of a “series + parallel” circuit. Here sets of two solar panels are connected in “series groups”. From there, each series group is connected together in a parallel circuit, using an MC4 connector to accommodate the positive and negative terminals from each series group.

Here, each solar panel group can function as a separate entity and generate its own maximum amount of electricity under different sunlight conditions. In addition, the total current of the system is limited by the parallel connection of several module groups. In the figure above, each series is rated at 5 amps, which together when connected in parallel add up to 20 amps. If each panel were just connected in parallel (rather than in 4 different series) then the total current rating would be 40 amps. This would require heavier gauge wire, which would not only cost more money up front, but also increase the risk of power loss during transmission.

How To Mount & Use Solar Panels With A Solar Generator

We are often asked how to set up and mount solar panels so that they can be used to charge solar generators. The truth is that solar panels can be positioned in any shape as long as they face the sun. This means that solar generators can work with both mounted and portable solar panels.

Permanent mounting of rigid solar modules

Depending on what you mount it on, solar panels can be permanently installed using a few different methods. The most common include the use of:

Z mounts

L brackets

rail systems

tile hooks (for tiled roofs)

And more

Small solar panels can be permanently installed on rooftops, ground poles, large vehicles, boats, and RVs, and used to charge the battery of a solar generator. If desired, a solar generator can be easily unplugged and transported to be charged or used at another location.

Installation of flexible solar modules

Flexible solar panels are very easy to install and can be attached in a variety of ways. They’re a practically attractive option for RV owners who don’t want to drill a hole in their roof.

Most commonly, flexible solar panels are installed temporarily (or permanently) using specially designed double-sided tape. This allows the solar panels to conform to a curved surface and is easy to attach and reattach.

Setting up portable solar panels for solar generators

Of course, sometimes portable power stations work best with portable solar panels. Foldable  solar panels (such as marine solar panels or solar panels for campers) are becoming more and more popular to transport high-efficiency rigid solar panels. Quite often, portable solar panels come with attached hardware that makes it easy to set them up at an angle to the sun.

How to monitor and maintain a solar generator

One of the best things about a solar generator is that it is extremely easy to maintain. There are no moving parts in a solar generator and you never have to worry about driving to the store for more “fuel”.

Today’s top solar generators usually have a long warranty period. As with any commercial product, attempting to repair a solar generator yourself is not recommended. Instead, it is advisable to send the device back to the manufacturer in the event of a system malfunction.