Can You Use a Portable Generator With Solar Panels?

Solar panels may or may not serve your total electricity requirement, and the system generates no energy at night and during unsuitable weather. Also, interactive, grid-tied solar systems don’t work during a power outage. So, can you use a portable generator with solar panels?

You can use a portable generator with solar panels, but its type or specifications should determine the installation. For instance, a portable solar generator isn’t an issue if it’s a hybrid inverter. Still, a portable gas generator should be isolated from the solar system.

You need to consider your specific setup to decide if and how you can use a portable generator with your solar panels. In this post, I have tried to cover as many variable factors as I can think of so that you can make an informed decision and plan accordingly. Read on.

How You Can Use a Portable Generator With Solar Panels

You may have one or more of the following solar panels and systems:

Grid-tied
Off-grid
Hybrid
Portable

Each setup has a few distinct prerequisites, which demand a specific type of installation. These prerequisites are also the variables that dictate whether or not you can use a portable generator with your solar panels. So, let me address the issues for each setup.

Interactive Grid-Tied Solar Systems

An interactive grid-tied solar system is connected directly to your utility supply line. Generally, a grid-tied setup has an interactive inverter, but there’s no battery. Such a system doesn’t operate during a power outage. The grid must be live for an interactive solar system to work.

Hence, you may need a portable generator to power the essential loads in your house. You may also want to run a portable generator to tactfully manage your time-of-use rates when there’s no solar power.

Irrespective of the reason, you can use gas or dual fuel portable generators with solar panels as long as the two aren’t connected. In other words, these two circuits should be segregated at a manual or automatic transfer switch (ATS).

This principle applies to both whole-home and portable gas or dual fuel generators if you have an interactive, grid-tied solar system. Here’s how you should connect the solar panels and the portable generator to your electrical circuit:

The grid-tied solar system should be connected to the utility supply line.
This connection is typically between the utility meter and the main panel.
Ideally, this circuit should have a fusible or fused disconnect switch.
The generator may use a manual or an automatic transfer switch (ATS).
Usually, a critical load sub-panel is set up for emergency power backup.
The manual or automatic transfer switch connects to this sub-panel.

Therefore, the grid-tied solar panels are disconnected from the load when a portable generator or whole-home power backup system is activated by the manual or automatic transfer switch.

Otherwise, an interactive solar panel system may detect the voltage of the portable generator. The interactive inverter can erroneously think that the grid is live, thus it will start the solar panel system. The system may feed electricity into the portable generator if the solar panels generate energy. This would be disastrous:

Your portable generator may suffer damage.
The electrical circuits may have problems.
The solar system may feed electricity into the grid that is down, risking the lives of those working on the power lines.

The above setup works even if you don’t have a separate critical load sub-panel for a portable generator. You can turn off the grid-tied solar system’s fusible or fused disconnect switch before starting the gas or dual fuel portable generator.

The switch will disable the circuit, thus separating the load and portable generator from the solar panels. And there won’t be a risk of the solar system back-feeding electricity to the grid, your house, or the portable generator.

Off-Grid Solar Panels With Batteries

Off-grid solar panels require an energy storage system, such as batteries. If there’s no solar power and the batteries are dead, you don’t have to worry about using a portable generator to run a load. There’s no risk of electricity backfeed from the solar panels to the generator.

However, you need a provision to separate the two power sources if you want them to operate simultaneously or alternatively. Here are a few practical options:

You can have separated loads and circuits for the solar panels and a gas or dual fuel portable generator.
You may use a fusible or fused disconnect switch for the off-grid solar panels to disable the circuit.
You can manually disconnect the solar system battery and power a load using a portable generator.

Hybrid Solar Panel Systems

Hybrid solar panel systems combine the features of interactive and off-grid installations. These features determine how you can use a portable gas or dual fuel generator.

For instance, some setups have a hybrid inverter that also serves as the battery to store solar energy. Also, some hybrid inverters can provide power backup. But these hybrid systems work only with solar panels. Therefore, you must disable them before running a portable generator.

The other type of hybrid setup is a battery energy storage system (BESS). All BESS solutions can store power from various sources, including the following:

Solar
Wind
Thermal
Nuclear

If a BESS setup has the provision for a gas or dual fuel portable generator to charge its battery pack, you can use it without worrying about the other sources feeding energy into the system.

Hitachi’s modular battery energy storage systems are compatible with diesel generators. Thus, you can use a portable generator and solar power to charge these systems. And the BESS system will run everything in your house, whether off-grid or connected to the power lines.

Portable Solar Panels

Portable solar panels require the following:

MPPT (charge controller)
Batteries and inverter
Or a power station

You won’t need separate batteries and an inverter if you have a power station such as the Jackery Portable Power Station Explorer (available on Amazon.com). This is an inverter and battery with a built-in MPPT charge controller. Plus, you can use a portable generator to charge the Jackery Power Station.

Hence, you can use a portable generator and solar panels and route the total energy through the Jackery Power Station.

Conclusion

Portable generators and solar panels can certainly coexist. However, most installations require you to separate their circuits. The exceptions are battery energy storage systems and power stations that can use multiple sources without segregated circuits, loads, fused switches, breakers, etc.