Solar panel systems, also called solar photovoltaic (PV) systems, are an increasingly popular choice for homeowners looking to reduce their carbon footprint and save money on energy bills. Before choosing a new system, you should know what options work for your roof, the best ways to connect the panels, and more. This guide walks you through the key steps of solar panel installation, from choosing the right location to maintaining the system.
How To Choose the Right Location for Solar Panels
The effectiveness of a solar panel system largely depends on its placement. Two main factors come into play when deciding where to install solar panels: tilt angle and orientation.
If you’re in the United States, the optimal tilt angle typically ranges between 15 and 40 degrees, depending on the latitude of your location. As for orientation, south-facing panels generally produce the most energy, followed by east and west-facing installations. North-facing panels are the least desirable due to their low energy production.
Solar panel angle calculators can help you determine the best tilt for your location and the orientation of your roof.
Types of Mount Systems
Homeowners must select the right mount system type (roof or ground) for their solar panels.
Roof-mounted solar panels are the most common choice for residential installations in the United States. They offer a better return on investment than ground-mount systems and save on space. However, your available roof space, as well as its pitch and orientation, restricts this design. There may also be obstructions, such as chimneys and vents.
Solar shingles are another option for your roof. They resemble conventional roofing materials but also convert energy. However, they tend to be more expensive to install than traditional roof-mounted panels.
Ground-mounted solar panel systems are an excellent alternative if you have ample yard space, especially if your roof isn’t ideal for panels. Since you can optimize the tilt and orientation, you can maximize energy production. They’re also easier to maintain and clean. It’s important to note that ground-mount systems are more typically expensive than roof-mount systems.
How To Install Solar Panel Mount Systems
Once you decide on a location, the next step is to install the mounting structure and secure the solar panels. The process differs depending on whether it’s a roof or ground installation. If you’re installing a roof mount, you’ll need to properly install the racking system or you could void your roof’s warranty.
Sloped Roofs
A railed system, a set of rails that hold the solar modules, is used for pitched roofs. You need to first identify the rafter locations. Then, add flashings along these spots to provide structural support for the system. IronRidge, a solar mounting racking manufacturing company, provides a short video on this process. Two sets of clamps and fasteners secure the rails, followed by the solar panels.
Flat Roofs
Flat roof installations often use a ballasted racking system, which harnesses the power of gravity. Installers add landscaping pavers or concrete blocks to the bottom of the system’s frame to hold the frame and top solar panels in place.
You can adjust the panels on this racking system between 5 and 30 degrees, depending on the type of panel and the manufacturer. You also have the option to install a dual-orientation (east and west) system. While it’s still less efficient than a south-facing system, this solution can provide more consistent energy production.
(a) Ballasted racking mounting system for higher tilt angles (20-30 degrees). (b) Flat roof mount system for lower tilt angles (5-15 degrees). Source: K2 Manufacturer
Ground Mounts
Ground-mounted systems require a different approach. A ground foundation using helical piles or concrete piers provides structural support to the panels and rails. The type of soil in your yard impacts the best foundation option.
A set of vertical aluminum pipes are installed onto the foundation, followed by the rails. Installers then place solar panels placed directly onto the structure.
How To Activate Your Solar Power System
After solar panel installation, the system needs to be activated. This involves interconnecting the solar panels, installing the inverter, and commissioning the system.
Interconnecting the Solar Panels
During this step, note that as long as the solar panels are receiving sunlight, they have an open circuit voltage. Be careful when handling them. For safety, disconnect the grid from the load so no electricity will flow.
To interconnect the solar panels:
- Choose a connector: MC4 connectors are the most common way to interconnect solar panels, but other types of solar panel connectors are available.
- Identify the maximum voltage limit: The maximum output voltage of the string shouldn’t exceed the inverter input voltage. Take temperature variations into account.
- Plan the system layout: Homeowners need to have a clear idea of which series of panels will be connected in a single string and the total number of strings. It’s common to set a series connection and send the string wires to a combiner box or directly to the inverter by connecting one panel’s positive lead to the next module’s negative lead. However, for small off-grid systems, you can connect panels in parallel or use series/parallel connections using the connectors.
- Install a rapid shutdown switch: The National Electrical Code requires a rapid shutdown switch in an easy-to-access location. In the event of a fire, this provides first responders with a clear path to the roof.
Installing the Inverter
Next, installers need to add the inverter, such as a high-efficiency sine wave inverter, which converts the solar panels’ direct current (DC) power into the alternating current (AC) power used in homes.
String inverters, the most common and cost-effective option, convert DC to AC for the entire array of panels. Thanks to their maximum power point tracking (MPPT), they can handle entire strings of panels without a combiner box. You generally install string inverters near the main electrical panel, providing centralized control and diagnostics.
Microinverters are another option, but they are more complex and expensive than string inverters. However, microinverters are more efficient for systems with varying panel orientations or shading issues, as they’re installed at each individual solar panel. This allows for better monitoring and the optimization of each panel.
Connecting the Inverter to Batteries (If Applicable)
For systems that include energy storage, the inverter is next connected to batteries. There are two main configurations: DC-coupled and AC-coupled.
DC-coupled configurations are common in stand-alone and small solar PV and recreational vehicle (RV) applications. The charge controller acts as the MPPT, while the battery inverter performs the DC to AC conversion. The setup typically includes battery-specific components to protect against overcharging and depth of discharge.
AC-coupled configurations, which use both a string inverter and a battery inverter, are more common in grid-tiered systems. The string inverter handles the DC to AC conversion, while the battery inverter manages the energy storage and grid interaction. This configuration is ideal if the homeowner wants to integrate additional renewable sources, such as wind turbines.
Connecting the Inverter to a Bidirectional Meter
In traditional setups, utility companies install meters to track energy used by the household. However, grid-tied solar PV systems allow energy to flow in two directions, turning the household into a load and a generator. This means your system can inject power into the grid, allowing you to benefit from net metering.
In this scenario, you need to add a bidirectional meter to track the energy going to and from the house. The system has to pass local electrical inspection and receive approval from the utility company to connect to the grid. Requirements and regulations for this setup can vary by state and based on the utility’s net metering policies.
Solar Power System Commissioning
Before turning on the solar power, you need to check that the inverter has been synced with the power grid. The configuration depends on the system and the manufacturer, but it’s easier with stand-alone or off-grid options.
If you’re uncomfortable handling the inverter or have a grid-tied system, we recommend consulting with a certified electrician.
Once you’re confident the inverter and system have been set up properly, you can flip the breakers to turn the solar power system on.
Solar Panel Maintenance
Once installed, solar panels require minimal care, but regular maintenance can provide the best performance. Annual inspections can help you keep an eye on the overall system’s health, confirm connections, and spot potential issues before they worsen.
Regularly clean the panels and systems, especially in dusty or low-rainfall areas, but use appropriate cleaning methods as advised by the installer or manufacturer to avoid damaging the panels. Most homeowners can clean their system with just water, but specialized solar panel cleaning materials are available as well. Never use bleach, detergent, or any other chemical on the modules.
Final Thoughts About Solar Panel Installation
Solar panels are a significant investment that can lead to substantial long-term benefits for homeowners. While some homeowners can handle DIY solar power installation processes, most should hire a professional to avoid potential issues, such as poor energy conversion or roof damage.
