Understanding MPPT and MLPE

The inverter space has never been stronger in the solar industry. But if you’re looking to start your first project or even if you have been installing solar for years there are a couple of 4 letter acronyms that can make your life a whole lot easier. MPPT and MLPE have been around for a while now, but there can still be some confusion about what they are, how they work, and what their benefits are. In this article, we tackle all of this and provide you with the answers you’re looking for.

What is MPPT?

MPPT stands for Maximum Power Point Tracking. It is a method of optimizing power produced by solar panels. MPPT achieves optimization by making the transfer of power (from panel to inverter) as efficient as possible, therefore producing more power. MPPT is made possible due to modifying resistance in the circuit, this happens at the inverter. Resistance in an electrical circuit is a measure of the opposition to current flow or factors that reduce current flow.

A key point to note with MPPT, voltage/amperage cannot be increased or decreased. Higher efficiency comes from increasing/decreasing the resistance compared to the current temperature of the panel or circuit.

What is MLPE?

MLPE stands for Module Level Power Electronics. MLPE is an extra layer of MPPT at the per-panel level. With an MLPE inverter setup, you have a microinverter or DC optimizer installed per panel. This is in contrast to MPPT where the inverter is connected per string of multiple panels. MLPE also provides panel-specific data vs. strings of multiple panels, this allows for more in-depth monitoring. MLPE also provides rapid shutdown- required by recent NEC (National Electrical Code), provides safety for EMS, workers, residents in an emergency or during service. Often you will see MPPT technology being used with an MLPE device.

What are the benefits of pairing MPPT with MLPE?

One of the benefits of using an MPPT inverter includes better production throughout the day and lifetime of the system, especially when shade is a factor. This is because with an MPPT inverter your system can track the current and voltage and find the maximum point at which your panels produce the greatest power. Combining an MPPT and MLPE device can also make a huge impact. With these devices, each panel can produce at maximum capacity even if some of the other panels are shaded. This is accomplished because you have MLPE devices on each solar panel. If one panel’s capacity is minimized due to shading this will not affect the others because each MLPE device controls each individual panel.

Additionally, MLPE devices provide added peace of mind with an extra layer of safety with protections in place for each solar panel compared to protection only at the system level. MLPE is often required, due to NEC codes in certain AHJs, to meet Rapid Shutdown Safety standards. Any jurisdiction operating under NEC 2017 or newer will require rapid shutdown on all non-ground mounted installs in populated areas. This includes homes, businesses, parking structures, stadiums, etc. Basically, anything that is not a field or empty building will require rapid shutdown capabilities for the system.

Currently, the majority of residential inverters use MPPT technology including SolarEdge, Enphase, and SMA products to name a few. You can also find MLPE devices when purchasing SolarEdge or Enphase products.

To talk more with a Greentech Renewables rep about the best-fit solution for your projects, contact your nearest location today.