Why Do You Need Optimizers—and What’s the Difference Between SolarEdge, APsystems, Tigo, and NEP?

If you’ve ever gotten a solar proposal and seen the word “optimizer” (or “MLPE”) next to your panels, you might be wondering:

• What does it actually do?

• Do I need one?

• Are all optimizers the same?

• How do they compare to microinverters?

Let’s clear it all up.

What Is a Power Optimizer?

A power optimizer is a device that attaches to your solar panel and adjusts its output to improve the performance of the entire system.

Why would you need that?

Because solar panels are usually installed in series—meaning they’re connected in a chain. If one panel is shaded, dirty, or underperforming, it can drag down the performance of every other panel in that string.

Optimizers fix this by working at the module level—they regulate voltage and current so each panel performs independently, even in less-than-ideal conditions.

The 3 Main Reasons to Use Optimizers

1. Shade Mitigation

Panels facing different directions, chimney shadows, or trees? Optimizers keep those shaded panels from killing the whole system’s output.

2. Performance Monitoring

Optimizers allow you (and your installer) to monitor the performance of each panel individually. This makes troubleshooting fast and easy.

3. Safety (Rapid Shutdown)

Most optimizers include module-level rapid shutdown features, which are required by the National Electric Code (NEC 2017 & 2020) for many jurisdictions. This keeps firefighters and technicians safe during emergencies.

Optimizers vs. Microinverters

Here’s the key difference:

• Optimizers work with a central inverter (like SolarEdge) and help panels perform better—but the DC power still flows to a central location for conversion.

• Microinverters (like Enphase) convert DC to AC right at the panel, so each module is fully independent.

Both systems solve the “shaded panel” problem, but with different architectures.

Key Players: What’s the Difference Between SolarEdge, APsystems, Tigo, and NEP?

Let’s compare the most common optimizer-based systems you might encounter:

1. SolarEdge: Proprietary Optimizers + Inverter

• How it works: Each panel gets a SolarEdge power optimizer that talks to a SolarEdge inverter. The two are codependent—you can’t use SolarEdge optimizers with other inverters.

• Best for: Full SolarEdge systems; performance tuning; high-efficiency arrays

• Features:

• Module-level MPPT

• Advanced monitoring

• Integrated rapid shutdown

• DC-coupled storage options (like SolarEdge Home Battery)

Pros: Excellent monitoring, DC-DC efficiency, great for shading

Cons: Requires proprietary inverter; less flexible in system design

2. Tigo: Universal Rapid Shutdown and Optimization (Optional)

• How it works: Tigo TS4 units attach to panels and work with any inverter. You choose the level of functionality—shutdown only, monitoring, or optimization.

• Best for: Installers using multiple inverter brands, or retrofits

• Features:

• Modular MLPE (choose your level)

• Universal inverter compatibility

• NEC-compliant rapid shutdown

• Selective optimization (only where needed)

Pros: Very flexible, can be installed selectively

Cons: Optimization isn’t as smart as SolarEdge; relies on paired CCA/data logger for monitoring

3. APsystems: Dual-Input Microinverters, Not True Optimizers

• How it works: Technically not optimizers—APsystems makes microinverters, which means each unit typically powers 2 (or 4) panels and converts DC to AC at the module level.

• Best for: Microinverter projects looking for Enphase alternatives

• Features:

• Independent module performance

• Monitoring included

• Scalable architecture

• Compatible with most panels

Pros: Cheaper than Enphase, works well in multi-orientation designs

Cons: Larger microinverter units, requires careful string planning

4. NEP (Northern Electric Power): Simple Rapid Shutdown and Optimization

• How it works: NEP offers both RSD devices and optimizer-style units that can work with most string inverters.

• Best for: Projects that need basic NEC-compliant safety and partial panel-level performance improvement

• Features:

• NEC 2017/2020 RSD compliance

• Minimalist design

• Compatible with most string inverters

Pros: Cost-effective, simple integration

Cons: Less advanced monitoring and optimization compared to others

So… Do You Really Need Optimizers?

Yes—if:

• Your roof has shading, multiple orientations, or obstructions

• You want module-level monitoring and performance tracking

• You need rapid shutdown compliance in your area

• You want to future-proof your system for expansion or smart home integration

No—if:

• You have a perfectly unshaded roof with all panels facing the same direction

• You’re using microinverters (which already offer module-level performance)

• You’re building a very small or budget-limited system

Final Thoughts: It’s About Design, Not Just Devices

No optimizer or MLPE brand is one-size-fits-all. The best choice depends on your:

• Roof layout

• Shading profile

• Local codes

• Monitoring preferences

• Inverter brand

• Budget

At Renewable Innovations, we help clients design systems with the right tech for the job—not just what’s popular or what comes in the default quote.

Want to Know What Your Roof Really Needs?

Let us run a full production and shading analysis. We’ll model performance with and without optimizers or microinverters, and give you a clear, no-fluff recommendation.

Book a consultation at www.reinnovations.org and we’ll walk you through it—panel by panel.