Editor’s Note: This article was developed by Brian Prusinski, with additional research by Gino Geruntino.

The residential PV industry is becoming more sophisticated. 

Following the feeding frenzy of 2021 and 2022, the market has slowly shifted toward more stringent specifications, higher performance, and a greater need for positive returns on investment (ROI). Especially for our ultimate customer, the homeowner. 

The industry is becoming more sophisticated, and customers are buying more smartly. That means looking for panels, parts, and professional installers that can help them get the most bang for their buck from installation through the entire lifespan of their balance of system (BOS). The shift coincides with net metering rules that have reduced what customers can sell to the grid. 

It’s no surprise that the residential solar installation market is one of the fastest-growing industries in the United States, despite a few hiccups (slower sales, less pressure to buy) on the local level. 

The Bigger Solar Picture

With more residential installations coming online, the need for qualified installers is paramount to the industry’s success. Although there isn’t a governing body for qualified installers, the need for continuing education, innovation, and consistency is becoming table stakes for solar companies nationwide. 

Residential solar installations have taken off recently, and 2023 is no different. In Q1 alone, 1,641 MWdc worth of electricity was installed, setting a first-quarter record. Although the total was slightly lower than in Q4 of 2022, this year’s strong start sets the tone for another year of industry growth, with California leading the way. 

With so many installations happening across the United States, the industry’s labor force has grown by leaps and bounds. In 2010, only about 93,000 people worked in the United States solar industry – today, that number is nearly three times higher, at about 264,000 workers, and showing no signs of slowing down. Despite several geopolitical hiccups and a domestic manufacturing industry struggling to come into its own, solar companies are showing resiliency and even enthusiasm for what’s to come. 

But the question remains: Does all this expansion open the door to more mistakes? 

How Do Residential PV Systems Work? 

Like their massive utility-scale cousins, residential solar energy systems use complex processes to transform solar energy into usable electricity. 

For an installed solar panel system to work, the panels on your roof must collect solar energy from the sun’s rays. That energy is converted into DC (direct current) electricity, then fed through copper wire to inverters that transform the DC electricity into AC (alternating current) electricity. On a utility-scale installation, the generated power is sent through aluminum wires to strategically placed combiner boxes, which combine individual strings into a larger conductor leading to the inverter. 

Once the AC electricity is generated, it flows to an electrical panel powering your home. Excess power can be stored in a battery for later use or fed into the larger electrical grid. 

With so many wires and parts, tight connections are critical to maintaining reliable and efficient clean energy. 

Connectivity is Critical 

When solar installers assemble PV systems on rooftops and in backyards, they often rely on field-made connectors, also called terminations. 

These connectors are not assembled by the manufacturer, but installers are given tools and instructions to ensure the terminations meet manufacturer specifications. This promotes long-term electrical performance, mechanical strength, and weather resistance. 

Of course, attaching connectors to the PV wire isn’t a one-step process. Several steps require precision, making it easy to perform them incorrectly. When that happens, it’s possible to leave gaps, loose fits, or other potential hazards. 

Workers start the connector process by stripping the wire to its conductor and removing the insulation. Once the bare conductor is ready, the pin is attached to the conductor using a crimper. Once that’s done, a fitting collar is placed on the wire, and the connector is fitted onto the pin. Lastly, the collar is pulled to the connector and firmly tightened with another tool. 

It’s a lot of steps, but each one is needed to correctly perform a residential PV install. Doing them wrong increases the risk of a loose connection, arc, spark, or potential fire.


Connection Issues Cause Concern 

When terminations aren’t made correctly, residential PV systems can suffer from several problems, including: 

Lower Energy Production/Energy Efficiency – Less power is generated when the connectors aren’t tight. This is because the connection isn’t allowing all the electricity generated from the panel to get to the solar inverter. Solar panels cost a lot of money, and homeowners can lose hundreds of dollars of electricity over time. Low efficiency makes it harder to recoup the expense of having the system installed in the first place. 

Shorter Lifespans – When connectors are loose, they produce more heat and stress on the entire system. If there’s too much heat, wires, connectors, and other parts of the balance of system (BOS) weaken, causing them to need replacing sooner than usual. 

Higher Overall Costs – When we mention higher costs, it’s not simply about producing less energy or replacing parts sooner than you thought. 

When mistakes happen, installers return to the site, check all the wiring, and replace what’s damaged. Finding a bad connector is not only difficult, but it costs valuable time that could be spent working on other projects and jobs. In some cases, workers may not be trained using the right technology to find bad connections easily, leaving them fumbling across roofs to check every connector. 
Those added installation costs result in lost labor, materials, and time, which could have been better spent on new solar systems instead of correcting issues at previous locations. 

For the homeowner, unexpected repairs can waste time and money. 

Improving and Maintaining Photovoltaic (PV) System Connectivity 

As former UCLA basketball coach John Wooden used to say, “Failing to prepare is preparing to fail.” 

No PV system is perfect, but that’s where proper maintenance comes in. Knowing what to look for and catching problems can save homeowners money and reduce the risk of them becoming larger over time. 

Get Your System Looked at by a Licensed Professional – Inspectors can test the entire system to find hot spots, detect poorly connected wiring, and spot other issues that may affect solar power output and efficiency. 

Use High-Quality Products – Good in usually means good out. That means avoiding cheap PV wire or solar inverter cable and not buying connections from the bargain bin because they “all do the same thing.” Work with manufacturers and distributors to determine the best connectors and wiring for the application. They know how their products perform in the field and what pairings work best, so they can point you in the right direction. 

Check, Then Check Again – Workers should double-check every connection, even if they’re sure they did it correctly. Loose fitting connectors are a drag on the system, so make sure every strip, crimp, and nut are done correctly, even when projects are moving quickly. If more than one worker performs the installation, they should check each other’s work to avoid oversights. 

Work With Your Factory Rep – It’s easy to get the right support and parts when workers have access to a reputable factory representative. These people often have in-depth knowledge of their products and accessories and can give you helpful advice to prevent problems down the road. 

Give Every Worker the Tools to Succeed – The industry is growing exponentially. With so many new workers, inexperience can breed bad results. 

Every worker should be trained to perform the job accurately, reliably, and quickly, with the right tools for the connectors they’re using for the installation. Manufacturers will often send specific items related to their connectors. Without them, the connectors may not be installed correctly. 

It’s also important to NEVER mix connectors from different manufacturers. Sure, they may say their parts are “MC4 compatible,” but that doesn’t mean they’re always a good fit, especially when multiple manufacturers are used on the same project. 

An Exciting Future Ahead 

This is an exciting time to be part of a fast-growing and lucrative industry! 

Installers can protect themselves and their customers from expensive and unnecessary mistakes with some preparation, training, and patience. That means training employees to use the right tools with the right connectors, understanding when things look off, and slowing down long enough to perform each termination correctly. 

It also means working with the manufacturers and distributors to learn how the wire performs in different situations and what connectors work best with them. Just because a connector or wire may work in a residential PV system doesn’t mean it’s the best option. 

Solar technology has been around for decades, but the residential solar industry is still relatively young. As it keeps gaining momentum, the need for well-trained and professional workers will be paramount to its success. It’s also on manufacturers and distributors to educate, guide, and assist installers when necessary. 

With a trained, reliable, and experienced workforce, it’s possible to supply clean energy to more homes and finally take the next step toward renewable energy.

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