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: 15-70 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: 9.3–28 kW


i13.5 String Optimizer

System voltages: 600–1000 V
Output currents: 12.0–13.5 A
Output powers: 5.9–12.2 kW


i12 String Optimizer

System voltage: 600 V
Output current: 12 A
Output powers: 4.8–6.8 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.


Ampt String Optimizers include V-match technology to automatically match the DC bus voltage while delivering full available power from the PV array. This increases system design flexibility, simplifies controls, and unlocks value across diverse applications.

High Fixed-Voltage Bus (HFVB)

Ampt’s HFVB technology enables the DC bus to operate at a constant voltage that is higher than variable voltage systems. The fixed voltage simplifies the connection and control of system components tied to the DC bus. The higher voltage delivers power at a lower current to reduce component and system costs.

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 battery converters, Ampt String Optimizers include Direct-to-Converter technology to operate the DC bus at a fixed voltage that is always higher than the battery voltage. This eliminates 50% of the battery converter’s power circuitry while increasing its power density to lower the converter’s cost per watt.


Ampt String Optimizers include Direct-to-Battery technology which allows them to connect directly to the battery and follow its state-of-charge voltage while delivering full power from the PV array. The optimizer, battery, and battery inverter share the same DC bus without using battery converters.

High DC/AC

This Ampt feature allows PV system designers to achieve optimal DC:AC ratios; 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.

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.