String-Level Power Management

Ampt String Optimizers are DC/DC converters that are used in large-scale PV plants to lower the cost and improve performance of new systems, upgrade existing systems to produce more energy, enable low-cost DC-coupled solar+storage systems, and provide string-level data for improved O&M. String Optimizer models are for system voltages ranging from 600 to 1500 VDC.


i50 String Optimizer

System voltages: 600–1500 V
Output currents: 32–50 A
Output powers: up to 70 kW


i32 String Optimizer

System voltages: 600–1500 V
Output currents: 20–32 A
Output powers: 11–45 kW


i20 String Optimizer

System voltages: 750–1500 V
Output currents: 16–20 A
Output powers: 9.1–27.7 kW


i13.5 String Optimizer

System voltages: 600–1000 V
Output currents: 12.0–13.5 A
Output powers: 5.8–12.0 kW


i12 String Optimizer

System voltage: 600 V
Output current: 12 A
Output powers: 4.7–6.7 kW

Distributed Power Conversion

Ampt String Optimizers have two inputs and one output back to the inverter. The String Optimizers are located between the PV source circuits and the combiner box on a PV system. The optimizer performs MPP tracking on each input and delivers full available power to the output at a voltage set by the inverter. This is done without requiring communication between the inverter and optimizers.


Ampt's Patented Features Increase System ROI

Ampt products feature patented technology that enables PV systems to deliver more value than traditional system designs without Ampt.

Dual MPPT per optimizer

Ampt String Optimizers put maximum power point tracking on each of its two input strings of PV modules. This mitigates or eliminates mismatch losses to deliver more energy under changing environmental and system conditions over the lifetime of the power plant.

High Fixed-Voltage Bus (HFVB)

Ampt’s advanced DC power management technology allows for HFVB system designs which turn the variable voltage of the PV array into a fixed and predictable DC bus voltage to achieve system-level economic advantages.

Ampt Mode®

Inverters in Ampt Mode® operate in a fixed or narrow input voltage range that is closer to the maximum system voltage. This allows the inverter to deliver a higher AC output voltage at the same current which raises the inverter’s rated output power up to 50% to lower the inverter’s cost per watt.

String Stretch®

Ampt’s patented String Stretch® technology puts voltage and current limits on the output of each optimizer which doubles the number of modules per string and allows for smaller conductor sizing per kilowatt delivered to save up to 25% on electrical BOS costs.


For DC-coupled energy storage systems with Ampt, the DC bus operates at a fixed voltage that is always higher than the battery voltage which eliminates 50% of the battery converters’ power circuitry while increasing its power density to lower the converter’s cost per watt.

High DC/AC

This Ampt feature allows PV system designers to achieve optimal DC:AC ratios (up to 3:1); expand the DC power on existing systems without replacing inverters, combiners, or cables; optimize inverter utilization; and increase storage durations – all at a lower capex.


The output of our optimizers matches the DC bus voltage set by the inverter or battery converter while delivering full available power from the PV modules. This uniquely allows PV arrays with Ampt to automatically adapt to legacy or future power equipment to repower existing systems, upgrade inverters, mix new and legacy PV modules, deploy optimized DC-coupled storage systems, and other applications.

Full Tracker Fit

Ampt optimizers overcome string-voltage sizing constraints to fit more modules on a tracker than systems without Ampt. Increasing the number of modules per tracker allows system designers to fully use the tracker’s mechanical capacity and lower tracker cost per watt.

Wireless Communication

Ampt String Optimizers incorporate wireless communication to provide optional string-level data that is highly accurate, synchronous, and scalable to improve O&M, as well as enhanced controls for storage applications.


Contact us for more information

Learn more about the unique advantages that Ampt String Optimizers deliver for your PV project.