30.4 × 33 × 17.5 in

Battery inverterSMA

SMA SI27-US208-20

Battery inverter, ac-coupled battery inverter. 1 model, 27 kW AC at 208 V.

UL 1741 SBCEC listed · Jun 1, 2026

Rated AC power27 kW
CEC weighted efficiency96.0%
Warranty10 years

AC output (grid side)

CEC Grid Support Inverter List (Oct 7, 2026) · SMA datasheet

Rated AC power27 kW
CEC-measured continuous output27.2 kW
Grid voltage208 V
Phase208 V (1-phase of 3-phase service)
Frequency60 Hz

Efficiency

CEC Grid Support Inverter List (Oct 7, 2026) · NLR SAM inverter library

CEC weighted efficiency96.0%
Night-time standby (tare)17.6 W
Power to start converting141.4 W

CEC weighted efficiency is measured by an accredited lab at six power levels and three DC voltages — the number to compare between inverters.

Grid & smart-inverter certification

CEC Grid Support Inverter List (Oct 7, 2026)

UL 1741 SB (3rd ed.)Yes — UL, certificate Feb 23, 2024
UL 1741 SA (SA8–SA13)No
Volt-VAr with reactive power priority (SA13)No
Freq-Watt / Volt-Watt (SA14–15)No
Disable permit service / limit active power (SA17–18)No
CSIP (IEEE 2030.5) conformanceVia gateway during testing (Y*)
Anti-islanding method groupsGroups 1, 5 (manufacturer-reported)
CEC listedJun 1, 2026

UL 1741 SB is required for new interconnections in California (Rule 21) since 2026.

Monitoring & communication

SMA datasheet

InterfacesWi-Fi, Ethernet, Modbus, SunSpec, CAN

Size, weight & environment

SMA datasheet

Dimensions (W × H × D)30.4 × 33 × 17.5 in
Weight229.3 lb (104 kg)
Operating temperature−25 to +60 °C
Made inmanufactured in Germany

Warranty

SMA datasheet

Standard warranty10 years

Compare with similar 27 kW inverters

CEC Grid Support Inverter List (Oct 7, 2026) · building permits

Inverter	Power	CEC weighted eff.	DC test window	UL 1741 SB	Latest CEC	SoCal permits
SMA SIxx-US208-20	27 kW–27 kW	96.0%	200–980 V	Yes	2026	0
Trystar OZPCS-RS35-FB0	24 kW–35 kW	95.0%	400–800 V	Yes	2025	—
Trystar OZPCS-RSxx-FB1	24 kW–40 kW	97.0%	400–820 V	Yes	2025	—
SMA STPSxxUS-20	27 kW–60 kW	98.0%	200–980 V	Yes	2024	—
Growatt WIT xxK-A-US L2	28 kW–55 kW	97.0%	380–650 V	Yes	2024	—

Same type and grid voltage, power range covering this model; same fields from the same sources.

About SMA

CEC Grid Support Inverter List (Oct 7, 2026)

ManufacturerSMA
Listed in CEC asSMA America
Websitesma-america.com
Models on CEC lists202

Other series

SIxx-US480-20STPSxxUS-20

Documents

manufacturer documents

PDF
SI27-US208-20 / SI60-US480-20 YEAR S LIMIT
Datasheet · SMA · Jun 2026

Questions & answers

How efficient is the SMA SIxx-US208-20?

The California Energy Commission lists a weighted efficiency of 96.0% for SMA SIxx-US208-20 models, measured at six power levels and three DC voltages.

Is the SMA SIxx-US208-20 certified to UL 1741 SB?

Yes — the CEC Grid Support Inverter List shows UL 1741 SB for all models.

Can the SMA SIxx-US208-20 be used with a battery?

The CEC lists it as a ac-coupled battery inverter.

What is the SI27-US208-20’s DC input voltage range?

CEC tested it at 200–980 V DC.

What warranty does it have?

10 years standard (manufacturer datasheet).

Sources

California Energy Commission — Grid Support Inverter List (solar and battery inverters), data as of Oct 7, 2026. Manufacturer-reported, confirmed by CEC against certificates and test reports.
SMA — datasheet SI27-US208-20 / SI60-US480-20 YEAR S LIMIT.
SMA — document library on the manufacturer’s website (links above).
NLR (formerly NREL) — System Advisor Model CEC inverter library (version 2026.7.3).
Building permits — Southern California permit portals. Equipment matched from permit descriptions.