Smart modules: All about DC-optimized solar panels

Many solar companies recommend pairing a solar array with power optimizers and a central inverter to enhance the performance of a solar panel system. While many people install power optimizers and panels as separate components, your installer may recommend a solar panel that integrates both components into one, also known as a smart module.

Smart or DC-optimized modules are solar panels with an integrated DC power optimizer. Manufacturers and distributors ship solar panels with the optimizers pre-attached to the back of the panels so that installers don't need to spend time storing, transporting, and assembling separate components.

When sunlight hits a solar panel, it generates direct current (DC) electricity. Most appliances cannot run on DC electricity, so you need a solar inverter to convert this DC electricity into usable alternating current (AC) electricity. Power optimizers are sandwiched in the middle of this process; they "condition" the DC energy, fixing the voltage of the DC energy so that it's more efficiently converted into AC once it hits the inverter. With smart modules, you still require a central inverter to finish the conversion process.

Smart modules are typically more expensive than a traditional DC solar panel due to the integrated power optimizer. Smart modules have several advantages over a more conventional solar setup that can make the added cost worthwhile.

Easier purchasing for solar installers

There are several "soft costs" associated with solar panel installations. While you won't see this number explicitly spelled out in solar quotes, they do contribute to the overall cost of your solar project.

One soft cost associated with installing solar is the time and effort required to obtain equipment. Your solar installer will work with manufacturers or distributors to purchase and ship solar panels and inverters that eventually end up on rooftops. By purchasing smart modules, installers can reduce the turn-around time because the solar panels and optimizers typically ship as two separate components (and potentially from two companies), and they can order, ship, and store them onsite as one complete part.

Installation times

One of the most valued benefits of smart modules is the ease of installation. Because the optimizer is already merged with the panel, installers don't need to spend time and energy carrying extra materials up to the roof or deal with manually connecting individual components. Faster and easier installations can help cut down on labor costs for your solar installer and consequently lower the total costs for you as the end purchaser.

Module level performance

Have you experienced turning on your Christmas lights in early December only to find out they're not lighting up? This can happen if only a single light on the string of lights is broken. Similarly, when your solar panels are hooked up to a string inverter, if one panel on the string isn't producing electricity because of shading or a product defect, it will affect the performance of the rest of the panels on that circuit.

You won't experience this issue with smart modules. Because the power optimizers work independently, a single solar panel or power optimizer that isn't producing electricity won't impact the production of the rest of the solar array.

Because the panels operate individually, it also means that you can monitor the performance of each unique panel rather than evaluating the system's production as a whole. This can also mean quicker maintenance: if your solar panel system is underperforming, you can easily see if it's one particular panel causing the issue.

Servicing

Solar panel systems require very little maintenance throughout their lifetime. This is because, same for ground-mounted systems with trackers, there are no moving parts to a solar panel system.

That said, should maintenance be required on a smart module, it's easy to perform. The power optimizers on the back of smart modules are easily detachable, making servicing your equipment relatively straightforward in the rare case of malfunctions.

While there are hundreds of different solar panel manufacturers, the inverter and power optimizer market is much more consolidated. There are two companies predominately responsible for manufacturing power optimizers utilized in smart modules today: SolarEdge and Tigo Energy.

SolarEdge

Most smart modules on the market today include SolarEdge's power optimizers. SolarEdge, a leading manufacturer of power optimizers and inverters, has partnered with several solar panel manufacturers to produce smart modules, including but not limited to Canadian Solar, JinkoSolar, UpSolar, and Axitec. In 2018, Panasonic also announced a new smart module series, the S-Series, that utilize SolarEdge components.

Tigo Energy

Similarly to SolarEdge, Tigo Energy has partnered with multiple solar panel manufacturers to build smart modules. Trina Solar and UpSolar currently offer smart modules using Tigo's optimizers. Vikram Solar also announced a new line of smart modules utilizing Tigo optimizers in the summer of 2018.

Smart DC-optimized and AC modules both include module-level power electronics, but the primary difference is the location of the inverter. Power optimizers condition DC electricity but don't convert it into AC - requiring a separate central inverter. AC modules, on the other hand, have microinverters integrated into each solar panel, so the conversion to AC electricity occurs right at the panel site.

There isn't a one size fits all rule for solar panel installations: while there are many advantages to installing smart modules, there are other good options to consider when choosing your solar equipment.

If you have a perfect southern-facing roof that experiences no shade throughout the day, a traditional string inverter is a perfectly suitable lower-cost solution for your solar panel system.

If your primary motivations for installing smart modules are the module-level performance characteristics, it's always worth comparing smart modules with DC solar panels paired with power optimizers or AC modules that also have these capabilities.

With all the solar equipment available today, comparing multiple options is a good idea. Shopping around is the best way to ensure you install the right solar equipment for the right price. You can sign up on the EnergySage Marketplace to receive up to seven custom solar quotes for your home or business. If you'd like to install smart modules, note them in your account so installers can quote accordingly.