How to Connect Solar Panels Directly to an Inverter

A typical solar power setup has the solar panels connected to the batteries and inverter, and together they produce energy. But batteries are not necessary for the system to work. You can connect a solar panel directly to an inverter and run your appliances.

Solar panels can be plugged directly into an inverter input. In a grid tied system, the solar panels and inverter do not need a battery because power can be transmitted and sent to the grid.

Step by Step Instructions

Connecting solar panels to an inverter is very easy. There might be some extra steps needed depending on the solar power kit, so check yours for more details.

These instructions assume you already have a solar panel kit and inverter. Otherwise we recommend the Renogy Solar Starter Kit as it has the connectors, panels and other essential parts.

Inverters are available in different capacities. For a basic system a 1000 watt inverter like the Maxpart Power Inverter will be enough.

1. If you have more than one solar panel, connect them together in series or parallel. A series connection increases the voltage, usually done to match the battery bank, while keeping the amps steady. A parallel connection keeps the voltage at the same level but increases the amps.

Since we are not using batteries, we will be do a parallel connection. Connect the positive lead of one solar panel to the positive lead of the other module. Repeat for all your other solar panels.

2. Connect the solar panel to the inverter. The connectors are included in your PV kit. Plug them into the proper input.

Once everything is set, test the panel and inverter. The system should start charging provided the sun is out. Just make sure all the wires are tight, otherwise you might run into problems like a solar panel with no voltage.

The basic steps are easy, but an extension cable may be required if the solar panels are far away. A ground mounted installation is easier to work with, but will still take some work if it’s a large array.

If you are not sure how to proceed, let a professional PV installer handle it. In an RV you can do this yourself, but it’s another matter if it the array consists of several PV modules. As we will point later, running solar panels and inverters without batteries, while possible, is not without difficulties.

Do You Even Need an Inverter?

A solar power system requires an inverter to convert DC into AC power. You do not need an inverter for DC powered devices like motors, as they can be connected directly to the solar panel.

To keep things simple:

• Solar panels produce DC power. You can connect any device or appliance that runs DC onto it directly. No need for an inverter or battery.
• An inverter is necessary to run any AC powered electronic device / appliance on solar power. A fridge runs on AC, so you cannot connect it to a solar panel. The inverter must first convert DC to AC before the current is transmitted to the fridge for use.
• A battery is used to store solar energy, so it is not necessary to run on a solar system. Grid tied solar systems do not necessarily require batteries because the grid serves the same purpose. But off the grid solar systems become severely limited without batteries.

If your house runs on solar power, you must have an inverter. It does not matter if it is on the grid or not. Most home appliances run on AC so an inverter has to be installed. The type of inverter you need depends on your power requirements however.

If most of your appliances run on the grid, a small inverter to run the microwave, blender or some tools will suffice. If you are off the grid, the inverter must be large enough to supply the power your household requires.

Can I Use Solar Panels and Inverter Off Grid?

Solar panels can be hooked up to an inverter whether you are on the grid or off it. If you are on the grid, the inverter will draw power from the solar array or the grid. If solar production is down, the inverter switches to the utility grid to run your home.

You can use an inverter in an off grid setup too. Connect it to the solar panel as described above. Once the panels have enough charge, the inverter will run your appliances.

While a solar panel and inverter only system can work off grid, it does not make a lot of sense to do so. And here is why.

Solar panels cannot provide power at night, or when it is cloudy or raining. Without solar power your inverter will not run, and neither will your appliances.

Solar panels can only run for as long as there is sunlight. If there are 6 hours of sun, that is how long the panel can run. More so, solar panel production is not consistent. It fluctuates depending on the sun’s angle, if there are clouds in the sky, etc. Some appliances do not perform well when the power supply fluctuates.

Suppose you have a 600W solar array and a 1000W inverter. You load 500W on the system. It is 2:00 pm and the panel is churning out 500 watts. But suddenly the sky turns cloudy. The panel output drops to 480 watts. The inverter and load shuts down due to lack of power.

This is not a problem if your system is on the grid. But for off grid cabins and houses, a battery bank or backup power is a must. The battery bank also has to be the right size for the inverter and solar array.

The only times it makes sense to use an inverter and solar panel without batteries off grid is for short periods. If you have to run an AC load for an hour or so for instance, you can do without a battery.

Considerations For Running a Solar System without Batteries

How you approach this depends on the installation you have or will use. Here are some pointers that you should mull over before buying putting together a solar system.

If You are on the Grid

If your solar system is tied to the grid, you have several options. First you can do without batteries, period. If you only run DC devices on solar panel and the rest on electricity, you do not need an inverter either.

If you want to operate AC appliances on solar, get an inverter that meets the power requirements. Check your monthly bill and use that as a guide. So if you consume 900 kwh a month, a 1000kwh inverter will be enough.

Use your monthly bill to determine how large your solar array should be. If you want to run everything on solar, then a 1000kw array is required. But if you are going to use AC for the large appliances, you can settle for a smaller system.

Batteries are not required, but if you want assurance in case the power grid goes down, you can install a battery bank. The battery capacity can be as large or small as you want it to be. Battery banks are used to supply only the essentials, but ‘essentials” vary from household to household.

The easiest way to figure this out is list all the appliances you want to run in case of a power outage. Total the watts and use that as a means to decide what batteries to buy. If the total is 4000 watts, you should get an 8000 watt capacity battery because FLA batteries can not be drained more than halfway through.

If You are Off the Grid

A battery bank is required if you want to run any AC appliances or devices after the sun goes down. If you have a backup power source like a generator, the lack of solar power will not be an issue. However you still need an inverter to use any appliances that require AC power.

Conclusion

What makes solar power appealing to a lot of people is the many different ways you can use it. Depending on whether the system is on or off the grid, you can decide to use an inverter with or without batteries. Either way you have full control on how to use and store solar energy.