The installation of most residential PV systems is usually better left to the pros, but if you have the right set of skills and expectations, installing your own system can be a realistic goal.
Is it common for homeowners to design and install their own solar-electric systems? Should I install my system or hire a licensed professional to do the work? What skills and tools do I need to tackle a home-scale PV project? How much will I save if I install the system myself?
We frequently get questions like these from Home Power readers. Rather than defaulting to the obvious answer, “it depends,” we explore a long list of variables you should thoughtfully consider before tackling the design and installation of your PV system.
Owner installation is definitely not for everyone. Like any home improvement project, it’s important to realistically assess your skills, and weigh the benefits and potential pitfalls. Installing a PV system certainly isn’t rocket science, but doing it well and safely requires experience working with electrical systems, some serious research, and plenty of sound advice.
First, it’s important to consider the size of the PV system you want to design and install. There’s a huge difference in the cost and complexity of a 12-volt PV system with a few modules, designed to power some tunes and a couple of lights, compared to a multikilowatt, roof-mounted, grid-connected system operating at up to 600 VDC.
The former small system can be a great DIY undertaking for most handy individuals. Unless you are working alongside a willing professional, however, the latter should not be tackled unless you have significant experience working with high-voltage wiring, a firm understanding of the National Electrical Code (NEC), and access to the required safety equipment.
System type is also a consideration. Battery-based and batteryless grid-tied solar-electric systems are quite different, and require different levels of preparation and involvement. You need to understand the system type you want to install, and then assess your abilities and interest to determine if you can handle the job.
Grid-tied systems can be batteryless or battery-based. Batteryless systems are the most common, and are also the simplest, most cost-effective, and most environmentally friendly. You can find examples of this system type in Home Power, in supplier catalogs, and around your community. Batteryless PV systems can be bought as packages from suppliers and, with the proper support, can be almost color-by-number. These systems can employ one or more central string inverters or microinverters, where each module is paired to its own small inverter. Microinverter-based arrays operate at 240 VAC rather than at high-voltage DC, making electrical wiring a little safer to work with. Whether you are using microinverters or central inverters, you’ll still need electrical skills, tools, and savvy, but batteryless grid-tied systems are actually quite straightforward, consisting primarily of racks, modules, disconnects, inverter(s), and wiring.
A grid-tied battery-based system is another matter. Introducing batteries involves more complication in planning, implementation, and operation. To start, you’ll need to know how much battery storage you want or require, which means you’ll need to know your backup load profile and how long a utility outage you want to protect against. Though you can buy some or even most parts of a battery-based power center pre-wired, you will still need to configure and wire your battery bank, tie it and your PV array into your power center, and then connect the system to your backed-up subpanel and the grid. Most will need someone assisting in person or on the phone as you plan and install the system. Operation of a battery-based system is more complex than a batteryless system, and the batteries will require varying levels of maintenance, as well as periodic replacement.
Going off-grid requires a commitment to providing all electricity to all of your loads, all of the time. The design phase is crucial—you’ll need to understand your load profile, your resource, and the equipment capabilities. While many off-grid systems have been built by DIYers over the history of the RE industry, designing and installing a code-compliant system for a modern off-grid home is not a job to take lightly. All of the system users in the household will need to be involved from the beginning if you want a system that doesn’t disappoint.