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SiC Raises Utility BESS Inverter Efficiency Above 99%
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Sungrow is integrating onsemi’s hybrid silicon-carbide (SiC) power modules into its PowerTitan 3.0 utility-scale platform, and onsemi reports that the change raises inverter-level efficiency by 0.4% to a peak exceeding 99.3%. The upgrade uses SiC MOSFETs in the high-frequency switching stages while retaining silicon devices elsewhere to balance performance and cost, and onsemi says the modules support power-conversion units up to 450 kW. Onsemi’s analysis estimates the 0.4% gain could save about 475 MWh of energy per year in a 100-MW battery installation. These details were first reported by Electronic Design. The efficiency gain reduces conversion losses and heat, improving operating cost and system economics for grid-scale LFP-based BESS that serve EV load growth and AI data centers.
At utility scale, even small improvements in power-conversion efficiency can have a meaningful impact on battery energy storage system performance and total cost of ownership.
Sergio Fissore, vice president and general manager of the IPD power division at onsemi
Key takeaways
- Efficiency gain: Onsemi and Sungrow report a 0.4% inverter-level efficiency improvement, with peak efficiency above 99.3%.
- Module architecture: Sungrow’s PowerTitan 3.0 will use a hybrid SiC power module combining SiC MOSFETs and silicon devices for three-level inverter topologies.
- Scale impact: Onsemi calculates the 0.4% gain could save about 475 MWh per year in a 100-MW BESS.
- Power capacity: The hybrid modules are intended to be used with power conversion units rated up to 450 kW, enabling deployments with higher overall power capacity.
Table of contents
How the hybrid SiC power module lifts inverter efficiency
The hybrid SiC power module combines silicon-carbide MOSFETs with conventional silicon power devices to focus SiC where it matters: the high-frequency switching stages. SiC MOSFETs switch faster and with lower conduction and switching losses than silicon in those stages, which cuts the energy lost inside the inverter during DC-to-AC conversion. The remaining parts of the circuit keep silicon devices to limit cost and preserve parts of the topology that do not benefit as much from SiC.
Sungrow uses this module inside a three-level inverter architecture on its PowerTitan 3.0 platform; onsemi says the change yields a 0.4% rise in inverter-level efficiency and a peak that exceeds 99.3%. The design also targets higher power density by reducing switching-related heat and enabling improved thermal management, a combination that lets suppliers offer larger power-conversion units while keeping conversion losses low.
Because the improvement occurs at the inverter — the component that converts stored DC into grid AC — the benefit compounds over many cycles and across large installations. Sergio Fissore, vice president and general manager of the IPD power division at onsemi, said even small percentage gains at utility scale can change the economics of a BESS deployment.
Why a 0.4% gain matters at utility scale
A fraction-of-a-percent improvement becomes material once the inverter serves megawatts of storage and cycles thousands of times a year. Onsemi’s modelling — cited by the companies — finds that a 0.4% inverter-level efficiency increase in a 100-MW battery energy storage system translates to roughly 475 MWh of energy saved annually versus the prior module, meaning more delivered megawatt-hours available for the grid without adding battery capacity.
Those saved megawatt-hours reduce fuel or purchased-energy needs that otherwise refill the stored capacity, lowering operating expenses and increasing asset utilization. Less energy dissipated as heat also eases cooling requirements, which can cut balance-of-plant costs and raise available overload capability during short, intense demands.
The scale effect is why producers stress inverter efficiency rather than cell chemistry alone: cell-level improvements increase stored energy, while conversion efficiency determines how much of that stored energy reaches the grid. Onsemi frames the 475 MWh figure as an example of system-level impact rather than a guaranteed outcome for every site.
Trade-offs, deployment limits and reliability considerations
Silicon carbide (SiC) delivers higher performance but typically carries a unit-cost premium versus silicon. The hybrid approach seeks to capture most of those efficiency gains while limiting cost exposure by deploying SiC where it yields the largest returns. The companies say this mix is intended to improve what they call "system economics," though the exact cost break-even will depend on device pricing, installation scale and the operating profile.
Chen Peng, general manager of energy storage conversion products for Sungrow’s Energy Storage business, said the architecture will support deployment of higher-performance storage solutions and deliver greater lifecycle value. That point highlights a second trade-off: suppliers and owners must validate field performance to confirm modelled savings, and project-level variables — dispatch patterns, ambient conditions and duty cycles — will determine the returns actually realized.
The design also claims improved overload capability and thermal performance, attributes that matter for heavy, short-duration demands such as AI data center power spikes. Those benefits are useful only if system-level engineering — controls, cooling and grid interconnection — is sized to exploit the SiC module’s headroom.
| Attribute | Previous-generation module | Hybrid SiC power module |
|---|---|---|
| Inverter-level efficiency | Baseline | 0.4% higher; peak >99.3% |
| Power-conversion rating | Earlier platform values | Up to 450 kW per unit |
| Device mix | All-silicon | SiC MOSFETs + silicon devices |
| System impact (100-MW BESS) | Baseline losses | ≈475 MWh saved per year (onsemi analysis) |
Case for and against rapid uptake
The case for
- Lower inverter losses reduce operating costs and increase deliverable energy, improving project-level returns.
- Higher power density and improved thermal performance enable larger power-conversion units, simplifying deployments for higher-power sites.
- The hybrid approach lowers the effective SiC cost by limiting its use to high-return circuit stages.
The case against
- A cost premium for SiC devices could offset the efficiency gains at some price points and for smaller projects.
- Realized energy savings depend on a project’s dispatch profile, ambient conditions and control strategy, so onsemi’s 475 MWh/year example may not apply everywhere.
- Integration complexity — controls tuning, cooling upgrades, and field validation — can delay benefits and add upfront capital expenditure.
What to be careful about
- SiC device price volatility that keeps module cost above the threshold where efficiency gains pay back.
- Project-level operating profiles that reduce cycling or shift losses to other system components, lowering realized MWh savings.
- Integration and commissioning complexity that increases initial capital expenditure and offsets near-term economic benefits.
The bottom line
The Sungrow and onsemi collaboration shows how targeted SiC deployment can push inverter-level efficiency above 99% and produce meaningful system-level energy savings at scale. The hybrid SiC power module targets the high-return portions of the inverter to lower conversion losses, reduce heat, and enable larger power-conversion units up to 450 kW. Owners should weigh the unit-cost premium for SiC, site-specific operating patterns and the need for field validation against the projected 475 MWh/year saving cited for a 100-MW BESS. Project teams that confirm field performance and fold the modules into appropriately engineered cooling and control systems are most likely to realize the modelled benefits.
What to watch
- Watch for a commercial availability or rollout date for Sungrow’s PowerTitan 3.0 platform; no date has been set.
- Watch for onsemi or Sungrow to publish field validation data that confirm the >99.3% peak efficiency and the 475 MWh/year saving; no date has been set.
- Watch for project announcements that specify using the hybrid SiC power module in utility-scale PPAs or microgrid tenders; no date has been set.
Frequently asked questions
How much efficiency improvement does the SiC upgrade deliver?
Onsemi and Sungrow report an inverter-level improvement of 0.4%, with peak inverter efficiency exceeding 99.3% on the PowerTitan 3.0 platform.
What does 0.4% mean for a utility-scale system?
Onsemi’s analysis estimates that a 0.4% inverter-efficiency gain could save about 475 MWh per year in a 100-MW battery energy storage system, increasing delivered energy without adding battery capacity.
Why mix SiC and silicon rather than switch entirely to SiC?
The hybrid module places SiC MOSFETs where switching losses matter most and keeps silicon elsewhere to limit cost; the companies say this balances performance with system economics.
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