Solar array

What is a solar array?

The most important part of a solar panel system is the solar array – it holds all of the panels in your system, which is where sunlight is collected and converted into electricity. In this article, we’ll share some common questions to ask yourself before installing a solar panel system on your home, and to make sure you get the most productive array possible.

Key takeaways

  • A solar array is a collection of multiple solar panels that generate electricity as a system.  
  • A solar array facing south will have maximum output (though east or west facing systems also provide ample energy).
  • The number of panels you need in your solar array will depend on factors like your electricity consumption, where you live, and the direction that your roof faces.
  • It’s possible to add additional panels down the line, but it’s easiest to right size your system initially.
  • Visit the EnergySage Marketplace to get quotes from our network of pre-vetted installers for your solar array.

What’s in this article?

How do solar arrays work?

Simply put, a solar array is a collection of multiple solar panels that generate electricity as a system. When an installer talks about solar arrays, they’re typically describing the solar panels themselves and how they’re situated – aka the entire solar photovoltaic, or PV system. To create solar energy, sunlight needs to hit your panels’ photovoltaic cells. The sunlight sets electrons in motion, producing direct current (DC) electricity. Your array is connected to an inverter or multiple inverters, which convert the DC electricity generated by the solar cells in your panels into usable alternating current (AC) electricity.

The term solar array is often also used to describe large-scale solar projects; however, it can refer to just about any grouping of solar panels. In this article, we’ll focus on residential solar arrays, which are typically located on your roof. For more information about large-scale solar arrays, check out our article on utility-scale solar panel systems.

What are community solar arrays?

If you’re a homeowner, you’ll save the most by installing a solar power system on your property – but what if you’re a renter or don’t have a suitable roof? Community solar arrays – or solar farms – are a great alternative to home solar installations. If your local utility company has open community solar projects in its territory, you can subscribe and save between 5 to 15 percent annually on your utility bills. In addition to saving money, you’ll also support the development of clean energy in your area. To explore community solar providers near you, visit our Community Solar Marketplace.

Does it matter where your array is located?

It’s certainly important to ask any installer about the system design and the location they’re proposing to put the solar panels. If you’re in the Northern Hemisphere, a solar array facing directly south will produce more electricity than one facing west, east, or north because it will receive more hours of sunlight.

Rooftops are a common choice to install your solar panels, but they’re certainly not the only one. If you have a lot of land available with plenty of sunshine, then you might consider installing a ground-mounted system instead. Ground-mounted arrays aren’t constrained by the dimensions of a roof, so you’re able to face and tilt the panels optimally for maximum production and produce more electricity over time.

In addition to rooftops, solar arrays are sometimes located on other structures like carports and gazebos. These installations aren’t as common, so you might have to ask around to find an installer in your market that can design and install this type of system. There also may be some higher costs associated with a stand-alone structure because of the additional components required for the installation.

How many panels do you need in your array?

A typical home needs between 17 and 21 solar panels to cover all of its electricity needs; however the exact number depends on the size of your electricity bill (among a number of other factors). Your savings will be the greatest if you try to cover as close to 100 percent of your electricity usage as possible – this may mean that you have to install a few more or higher wattage panels than your next-door neighbor if you have different energy needs for your home.

The number of panels you need also depends on the location of the panels, both in regards to your geographic location and the design itself. As far as geography goes, the same solar panel in California will produce more electricity than in New York because California gets more sunshine over the course of a year. Installers take your geography into account when estimating the production of your solar panel system and will propose a design accordingly.

The physical location of your array and the direction it faces is also an important factor: if your roof faces east/west, you’ll need to install more panels to reach the same amount of production as a south-facing system.

Can you install more than one solar array?

In some cases, your installer will recommend a solar panel system made up of multiple arrays that are connected and supply electricity to the same meter. However, multiple arrays can result in a higher installation cost because of the additional labor requirements to install them. 

In addition, if you install multiple arrays that are facing different directions, you may want to consider using either power optimizers or microinverters as your inverter solution. Also known as module-level power electronics (MLPE), power optimizers and microinverters help complicated solar panel systems produce electricity efficiently by optimizing the production of each individual panel. In contrast, with a standard central string inverter, one panel underperforming can lower the production of the other panels on the same circuit.

Can you add capacity to your solar array in the future?

You may be considering adding solar panels to your system in the future if you have plans to increase your electricity consumption down the line. Whether you’re thinking of purchasing an electric vehicle (EV), installing a hot tub, switching to air source heat pumps, or any number of other home upgrades, there are plenty of reasons to expect your electricity costs to increase. If you have additional space available for more panels, it’s certainly possible to add onto your system at a later date – but, you’ll want to keep a few things in mind:

Choose efficient equipment

First, if you have limited space, you should consider paying more for high-efficiency and high power output equipment – like panels from SunPower, Panasonic, or REC – when you install your first array. This maximizes your overall electricity production while saving space for new panels in the future.

Use your original installer

Next, ask your installer if they have performed add-on projects. Some installation companies will shy away from doing add-on projects if they didn’t install the original system because they’re worried about conflicting warranties. It’s usually easier to work with the company that did the initial installation in order to avoid any issues.

Plan for future electricity consumption

Finally, if you’re certain that your electricity use will increase soon, you may want to consider oversizing your system initially to avoid an add-on project in the future. By doing so, you’ll save on costs for labor and permitting. You’ll also be able to take maximum advantage of incentives available now that may not be down the line, such as the 30 percent federal tax credit for solar that’s set to drop to 26 percent in 2032.

How to install your own solar array

At EnergySage, we always recommend comparing your options. Sign up on the EnergySage Marketplace to receive quotes from multiple pre-vetted installers so you can start generating renewable energy with your own solar array. If you have any strong preferences about your solar panel system, simply make a note in your account so installers can tailor their quotes to your needs. If you’d like to start out your solar research with an estimate of costs and savings, try our Solar Calculator.