Solar Power Converters: DC-DC Stages, MPPT and DC-Coupled Storage

Finding

DC-DC conversion is no longer a hidden stage inside the inverter; it is becoming the architecture of solar plus storage

In a DC-coupled plant the battery's bidirectional converter sits on the same 1,500 V DC bus as the PV array, so midday output above the inverter rating charges the battery instead of being clipped. The same topology lets depots and factories run DC fast chargers straight from solar and storage.

Converters show up in four places. MPPT boost stages are built into nearly every inverter and constantly adjust array voltage to the maximum power point. Panel-level optimizers (SolarEdge, Tigo, Huawei) move MPPT to each module and satisfy the US rapid shutdown rule in NEC 690.12. Charge controllers (Victron, Morningstar, OutBack) do the same job in off-grid battery systems. Bidirectional DC-DC converters (Dynapower, Power Electronics, Sungrow, SMA) tie utility batteries to a PV bus.

The devices follow the same path as inverters: silicon MOSFETs at low voltage, SiC at 1,000-1,500 V, and GaN in compact module-level designs. Isolated DC-DC stages built on high-frequency transformers are also the core of solid-state transformers and DC fast chargers, so the supply chain overlaps with EV charging.

Topologies

Converter topologies

Solar DC-DC converter topologies
Topology	What it does	Where it is used
Boost	Raises DC voltage	MPPT stage of string inverters; low-voltage strings onto a higher DC bus
Buck	Lowers DC voltage	Charge controllers feeding 12-48 V batteries
Buck-boost	Raises or lowers voltage as irradiance changes	Panel optimizers and module-level MPPT
Isolated DC-DC	Transformer-isolated; galvanic separation	Safety-critical links, DC fast chargers, solid-state transformers
Bidirectional	Power flows both ways	DC-coupled batteries, vehicle-to-grid, hybrid inverters
Resonant (LLC, dual active bridge)	Soft switching at high frequency for low loss	High-density isolated stages in chargers and utility DC-DC

Products

Four converter products in solar systems

Solar DC-DC converter products
Product	Job	Vendors
Panel optimizer	Per-module MPPT and rapid shutdown	SolarEdge, Tigo, Huawei
MPPT charge controller	Charges a battery from PV in off-grid systems	Victron, Morningstar, OutBack, EPEver
DC-coupled storage converter	Ties a utility battery to the PV DC bus	Dynapower, Power Electronics, Sungrow, SMA
Rapid shutdown device	De-energizes roof conductors within 30 seconds	Tigo, APsystems, SolarEdge

Makers

Solar DC-DC converter makers

Grouped by the four product types above, minus the MPPT stage built into every inverter. Active companies first, then planned, closed and bankrupt ones.

Optimizers and rapid shutdown

Module-level optimizer and rapid shutdown makers
Company	Products	HQ	Plants	Technology	Status
APsystems	RSD-S rapid shutdown devices	China	China	Module-level rapid shutdown	active
Fonrich	Rapid shutdown devices	China	China	Module-level rapid shutdown	active
Huawei	SUN2000 smart optimizers	China	China	Module-level optimizers	active
SolarEdge	S-series power optimizers	Israel	US (Austin, Texas), Vietnam	Buck-boost optimizer per module	active
Tigo Energy	TS4 optimizers and rapid shutdown	US	Not disclosed	Module-level optimizers and rapid shutdown	active

Charge controllers

Solar charge controller makers
Company	Products	HQ	Plants	Technology	Status
EPEver	Tracer charge controllers	China	China	MPPT and PWM charge controllers	active
MidNite Solar	Classic charge controllers and rapid shutdown	US	US (Arlington, Washington)	MPPT charge controllers	active
Morningstar	TriStar and ProStar charge controllers	US	US	MPPT and PWM charge controllers	active
OutBack Power	FLEXmax charge controllers	US	Not disclosed	MPPT charge controllers	active
Renogy	Rover charge controllers	US	Not disclosed	MPPT and PWM charge controllers	active
Schneider Electric	Conext MPPT charge controllers	France	Not disclosed	MPPT charge controllers	active
Victron Energy	SmartSolar and BlueSolar MPPT charge controllers	Netherlands	Not disclosed	MPPT charge controllers	active

Utility DC-DC and DC-coupled storage

Utility DC-DC and DC-coupled storage converter makers
Company	Products	HQ	Plants	Technology	Status
Alencon Systems	SPOT string-level DC-DC converters	US	US	Utility string optimizers for DC-coupled storage	active
Ampt	String optimizers	US	Not disclosed	Utility string optimizers; raise DC bus voltage	active
Dynapower	DPS DC-DC converters for DC-coupled storage	US	US (South Burlington, Vermont)	Bidirectional DC-DC	active: Owned by Sensata
EPC Power	Bidirectional DC-DC converters and storage inverters	US	US (Poway, California)	Bidirectional DC-DC	active
Power Electronics	Freemaq DC-DC converters	Spain	Spain, US	Bidirectional DC-DC	active
Sinexcel	DC-DC converters and storage PCS	China	China	Bidirectional DC-DC	active

Sources

Sources and scope

Scope: Solar Power Converters
Sources: NFPA 70 (NEC) Article 690; vendor data
Updated: October 2026

Solar Power Converters