Any time you're making a major investment, you should put in the effort to study up on the decision, read up on all your options, and ensure that the investment you're making is a good one. Installing solar for your home will likely cost tens of thousands of dollars, and it's not something you should go into blindly. You should thoroughly research solar power equipment to understand better what you're investing in. This article will give you a more in-depth look into solar inverters, how they work, their types, and the key factors to look for when buying one. Keep reading to learn more about solar inverters so you can make an informed purchase.

What Do Inverters Do?

Before you learn about the types of inverters and the factors to look for when buying one, you should first understand what an inverter is and its purpose within your system. The solar panels on your roof generate DC (direct current) electricity; however, your home primarily runs off of AC (alternating current) electricity. We won't go into the details about the flow of electrons and how these two types of power differ but suffice it to say that your home cannot run directly off your panels' power. That's where the inverter comes in.

An inverter's key purpose is to convert DC power into AC electricity. This conversion takes place in a tiny fraction of a second, providing your appliances, lights, and electronics with power almost instantaneously. Inverters can perform some other tasks, too, depending on the exact type of system you have, but their primary role is always the conversion between DC and AC power.

What Are the Types of Inverters?

In order to understand the types of inverters available, we first need to understand the different types of solar power systems. There are three different types of system designs:

  1. Off-grid – This type of system is completely disconnected from any city-supplied power source. It's most commonly seen in remote areas where grid power is not accessible. An off-grid system is typically much larger, as it must be entirely self-sufficient and will always include a backup power source (sometimes multiple) when solar energy is unavailable. Off-grid inverters are designed to connect to these backup power sources and, in the case of solar batteries, charge them with excess energy from the solar system.
  2. Grid-tied – A grid-tied or on-grid system is connected to the city power grid. Because these systems have city power as a backup energy source, they don't require any other backup power sources. They can also often feed excess energy into the city grid for a utility credit, making the grid a sort of energy storage option for some grid-tied solar users.
  3. Hybrid – Hybrid systems offer the best of both off-grid and grid-tied systems. They connect to the stable power source supplied by the grid. Still, they can also accommodate a backup power source like a solar battery so that users can achieve energy independence if desired.

You'll need to make sure you purchase an appropriate inverter for your system's design. Inverters are designed to fit within each of these systems, with off-grid inverters connecting to backup power, grid-tied inverters connecting to the grid, and hybrid inverters accommodating both of these inputs. In addition to this, there are several different styles of inverters that can be connected within each of these systems. These include the following:

  1. String inverters – Also called central inverters, string inverters are probably the most common option for residential solar users. They work well for simplistic system designs, in which the solar panels are connected in a straight line, or "string," much like a strand of Christmas lights. That string of panels is then connected to the inverter. While the cheapest option, string inverters, and the way the panels must be connected to use one can drag down our panels' productivity. If one panel in the string is shaded, the rest of the panels will become less efficient in their energy production, regardless of whether or not they're still in full sunlight.
  2. Power optimizers – While not an inverter in their own right, power optimizers can help to offset the issues that come from using a string inverter. Power optimizers are mounted directly to each solar panel, helping to isolate them from one another's productivity problems. This can keep power output higher while still feeding to a central or string inverter.
  3. Microinverters – Microinverters attach to individual panels as power optimizers do, but unlike power optimizers, they are inverters in their own right. Rather than having DC power flow through the wiring to a central inverter to be converted to AC power, the DC energy flows directly into the microinverter on the panel, converting it to AC power before sending it into the home. Microinverters are best for providing maximum energy output and are the ideal choice if you have a more complex system design, such as one in which the panels on your roof face in different directions.

As we said, these three types of inverters can be installed on any system design, whether on-grid, off-grid, or hybrid. So, deciding which type of inverter you want in your system will depend largely on your priorities. If you can fit micro inverters into your budget, we strongly recommend electing these panel-mounted inverters over a string inverter. Though microinverters are more expensive than string inverters, the increase in productivity will likely end up paying for that added cost in just a few years of use.

Choosing the Right Inverter

Of course, within every category of inverter, there are several manufacturers and different models to choose from. When choosing a make and model of inverter, there are three areas you should examine:

  • Performance specifications
  • Lifespan
  • Warranty

Each of these factors will impact the overall cost per watt that the inverter provides, which is the final determination of how much value you get from your investment. If you need guidance in choosing an inverter or would like to learn more about our solar financing for residential projects, contact The PowerStore, Inc., today.