Renewable Energy: Solar

Submodule Optimizers (Solar DC-DC Converters)

Boost string length by up to 30% for a better return on investment. Yes, solar power is clean and renewable, but cost-effectiveness is equally critical. We're helping the industry compete against coal and natural gas, with power electronics designed right into next-generation solar panels for a better available energy harvest. Our submodule optimizers enable maximum power point tracking (MPPT) and DC optimization to be performed on each cell string. With up to a 30% increase in the number of modules per string, now even the largest photovoltaic (PV) projects can achieve markedly better financial performance.

Our submodule optimizers are highly integrated DC-DC converters that replace traditional bypass diodes to more effectively reduce the impact of series and parallel mismatch. Rather than completely bypassing an underperforming cell string, the solar DC-DC converters actively harvest the available power and regulate the cell string's output current. This ensures the underperforming cell string can always contribute power without impacting the output of the highest performing cell strings.

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Take the Next Step in DC Optimization

Our submodule optimizers embed the maximum power point tracker (MPPT) function deeper in the photovoltaic system than ever before. You’re no longer constrained by the limits of conventional PV system design. Submodule optimizers enable longer series strings and the use of higher voltage- and power-rated PV inverters. Together, the added flexibility reduces overall DC and AC copper, combiner, and installation labor costs. Combined with mismatch energy recovery afforded by submodule optimization, you will deliver improved financials for even the largest PV projects.

This is DC optimization without costly boxes hanging off the back of your panel, without network cabling or communications gateways, and without hotspot stresses. Submodule optimizers enable you to perform MPPT and DC optimization on each cell string. This granularity minimizes power degradation due to shading, soiling, and other sources of mismatch within the panel.

Unlike the diodes they replace, submodule optimizers do not bypass weak cell strings. Instead, they allow each cell string to deliver maximum power under any environmental conditions, enabling you to harvest more energy, achieve denser panel layouts, and improve system reliability.

Submodule optimizer solid state, single-chip device


Solar Cell Optimizers Offer Huge Gains in Energy Harvesting
1:33 June 30, 2015


Longer PV Module Strings

By limiting the maximum output voltage of each module to a constant voltage, the maximum PV module string length can be expanded by 30%. Longer strings allow the use of less copper, fewer combiners, higher AC voltage/power inverters, and simpler installation

Increased Energy Harvest

Performing maximum power point tracking (MPPT) separately on each cell string (from 20 to 24 cells) eliminates performance mismatch at the most granular level providing a superior level of shade tolerance.

Expanded System Size

Improved performance with row-to-row shading allows you to increase ground mount or roof-top energy density, so you can generate more energy from a constrained space.

Extended Reliability

Submodule optimizers replace the need for bypass diodes. This improves long-term panel reliability by eliminating hot-spots and minimizing the impact of power degradation mechanisms.

Lowest Solution Cost

A fully integrated submodule optimizer solution costs less than DC optimizer modules, and requires no additional hardware, specialized PV inverters, or data services.


Submodule Optimizers increase energy density.

Submodule Optimizers replace bypass diodes to maximize energy production and reliability.


Get Optimal Output Under Any Environmental Conditions

Submodule optimizers work to increase the current output of an under-performing cell-string so that it does not impair the output of the other cells within the module, or other modules in the system.

The submodule optimizer MPPT function works alongside the inverter MPPT to ensure the system output is optimal under any environmental conditions. Three of our submodule optimizers replace the three diodes found in a conventional panel.

Conventional or Panel Optimizer Panels

Submodule Optimizer Panels


Solar Junction Box Partners

To enable leading module OEMs to rapidly bring a Maxim-enabled module to market, Zerun Electronics Technologies Co. has introduced the ZS, Z8S, and Z10 turnkey junction-box solutions which incorporate Maxim’s submodule optimizer ICs. Zerun was established in 2009 and is a leading manufacturer of PV solar system interconnection accessories including junction boxes, connectors, and cable assemblies. The company’s professional R&D and manufacturing staff ensure Zerun products are excellent quality, highly reliable, operate efficiently, and are cost-effective.