When winter shuts down solar storage: how Ampace is solving Europe’s cold-climate challenge

Ampace, a joint venture between battery giants CATL and ATL, believes it has engineered a solution that eliminates the winter performance penalty entirely, whilst simultaneously addressing customers’ deeper anxieties around safety incidents, performance degradation and technology obsolescence.

Dr. Yuan, chief technology officer of Ampace, spoke with Energy-storage.news about how the company is tackling Europe’s most persistent residential storage challenges, and why five years of operational experience in the European market has shaped its approach to product development.

Breaking the winter performance barrier

Winter downtime and auxiliary heating losses are persistent complaints from residential storage owners in Northern Europe, and the industry has struggled to solve this fundamental challenge. Systems are often designed around cells optimised for moderate climates, then try to compensate at the system level with external heating. That approach has fundamental limitations—it adds cost, complexity, and consumes more energy.

According to Dr. Yuan, “delivering reliable operation at -25°C without auxiliary heating whilst staying safe in high heat is not the result of a single component—it is a system-level co-engineering achievement spanning cell electrochemistry, intelligent thermal management and robust mechanical design.”

With the PR-S3 Elite, the company says it has “designed a proprietary thermal management strategy that captures and redistributes the internal heat generated during controlled charge-discharge pulses at cold start. Combined with advanced insulation and passive cooling pathways, the system keeps the cell core within its optimal temperature window without external heating devices, whilst also preventing hot-spot accumulation in high-temperature ambient conditions.”

This capability is only possible because Ampace controls the full vertical chain—from cell chemistry to thermal architecture. Dr. Yuan emphasises that “a defining requirement across Northern and Alpine Europe is the ability to charge and discharge reliably at sub-zero temperatures without auxiliary heating, ensuring year-round solar self-consumption.”

Addressing the three deepest customer concerns

Cold-climate performance represents just one pain point in a broader landscape of customer anxiety. Dr. Yuan says that “the deepest customer concerns cluster around three areas: safety incidents, unexpected performance degradation, and the risk of stranded assets due to technology obsolescence or unreliable support.”

The company’s approach recognises that European customers’ requirements are united by three overarching goals—energy independence, cost certainty and uncompromising reliability—but the emphasis placed on each differs between residential and commercial-industrial segments. For residential customers, homeowners expect a compact, quiet, easy-to-install system that requires minimal maintenance. “They also demand an ultra-long cycle life to lock in long-term savings and avoid premature replacement,” Dr. Yuan notes.

Whether residential or commercial, “European customers increasingly require carbon-conscious manufacturing and full compliance with EU safety and grid-code standards, so that their energy storage asset also strengthens their own ESG credentials.”

Intrinsic safety through chemistry-level design

Safety concerns have been amplified by high-profile thermal runaway incidents in other markets, creating genuine anxiety amongst potential storage adopters. Ampace’s approach starts at the cell chemistry level rather than relying solely on system-level mitigation. According to Dr. Yuan, the company eliminates safety risks “at the root: our semi-solid LFP cells use an electrolyte-lean design without free liquid electrolyte, fundamentally preventing leakage and suppressing thermal runaway. This intrinsic safety approach, reinforced by our ONEN Strategy’s pledge of zero safety incidents, provides the strongest possible assurance.”

This represents chemistry-level prevention rather than system-level mitigation. When there’s no free liquid electrolyte, the fundamental mechanism for thermal runaway propagation is eliminated, offering a qualitatively different safety proposition than adding more sensors or fire suppression to conventional liquid-electrolyte cells.

Engineering for ultra-long cycle life

The second major concern—performance degradation over time—is addressed through what Dr. Yuan describes as a comprehensive engineering strategy. “The 15,000-cycle design life is the outcome of a holistic strategy that starts with cell material science and extends through intelligent system control. It directly translates into two tangible customer benefits: dramatically lower lifetime cost and absolute peace of mind.”

At the foundation, the company uses “specially formulated LFP cathode materials with highly stable crystal structures, together with electrolyte additives that suppress parasitic side reactions. This results in extremely low rates of both calendar and cyclic ageing, forming the foundation for our zero-degradation guarantee over the first three years.”

Dr. Yuan explains that the company’s “BMS goes far beyond basic protection. It continuously estimates the state of health of each cell and adapts charging strategies in real time, avoiding stress conditions—such as high voltage or high current at extreme temperatures—that accelerate wear. Cell balancing is maintained with minimal energy dissipation, further preserving usable capacity over time.”

The result for customers is compelling: “over 15,000 cycles, the per-cycle cost drops so significantly that it fundamentally reshapes the lifetime economics for a household. More importantly, the zero-fade promise in the first three years and the FrostCore-enabled all-season reliability mean homeowners never need to worry about performance drop-off, unexpected replacement, or winter downtime—it is designed to be a decades-long, truly worry-free asset.”

Future-proofing through strategic partnership

The third concern – technology obsolescence and stranded assets – is addressed through Ampace’s unique position as a CATL-ATL joint venture. Dr. Yuan notes that “fear of technology lock-in or orphaned products is real. As a CATL-ATL joint venture with a five-year operational track record in the European residential market and strategic partnerships with leading local brands, we offer both stability and a visible innovation pipeline—from commercialised semi-solid state cells to our next-generation power conversion architecture. Customers invest in a platform that evolves with the market.”

The CATL relationship provides tangible benefits beyond brand recognition. “Ampace is a joint venture established by CATL and ATL, focuses on behind-meter Energy Storage. Co-developing the AG440 with CATL is therefore a natural extension of our shared technological lineage: CATL contributes its world-leading cell technology, whilst Ampace brings system-level integration and application know-how. The result is a product that delivers unmatched performance, safety and reliability—the best of both companies in a single offering.”

Critically, “CATL’s material security and financial strength provide a robust, predictable supply chain. For customers, this means confidence that their assets will be supported over a 15-year horizon, directly enhancing project bankability, insurability and long-term return on investment.”

The vertical integration advantage

Dr. Yuan emphasises that vertical integration from cell to system is fundamental to Ampace’s ability to solve these interconnected challenges. “If I had to distil what makes Ampace fundamentally different, I would point to three things that are difficult for typical integrators to replicate.”

First, the company is “not just a pack assembler. We inherit over 20 years of lithium-ion experience from CATL and ATL, meaning deep battery expertise is in our DNA from day one. Ampace therefore covers the full chain from cell to module to system R&D and manufacturing. This vertical control allows us to break trade-offs that normally force customers to choose between, say, low-temperature performance and long cycle life. We deliver both in the same product without prohibitive cost premiums.”

Second, Ampace brings “a proven, market-specific European commitment. With five years of residential storage operations in Europe and strategic partnerships with leading local brands, our insight is not theoretical. We understand Europe’s diverse grid codes, climatic zones and customer expectations through lived experience—and our products are purpose-built to meet them, not adapted after the fact.”

Third, the company offers “a roadmap that makes today’s choice future-proof. From commercialised semi-solid state cells to FrostCore Tech, we are already delivering the technologies that will define the next generation of storage. Choosing Ampace means choosing a partner whose innovation trajectory is moving faster than the market’s evolving demands—and that is, ultimately, the strongest assurance of long-term value.”

Extending solutions to commercial and industrial applications

Beyond residential applications, Ampace is targeting commercial and industrial segments with the AG440, where operational requirements become even more demanding. According to Dr. Yuan, “business users need systems that can flexibly operate both on-grid and off-grid, supporting applications such as peak shaving, energy arbitrage and backup power across factories, logistics centres, shopping facilities and microgrids. High round-trip efficiency, wide compatibility with mainstream European inverters, and stable operation in extreme temperatures are non-negotiable—they directly determine uptime and return on investment.”

The AG440 applies the same vertical integration approach to deliver solutions for these requirements. “The AG440 is engineered for stable operation across wide temperature swings. These figures are not marketing claims—they are validated by our cell and system testing and are being delivered in the field.”

The thermal management that enables -25°C residential operation translates directly to commercial-industrial reliability. “On the high-temperature side, multi-layer physical shielding, active airflow design and intelligent derating algorithms work together to ensure the system never enters a dangerous thermal regime. This simultaneously protects safety, preserves cycle life, and maintains performance even when ambient temperatures soar.”

The CATL partnership in practice

The practical implications of working with CATL extend across multiple dimensions. The partnership elevates products “across three dimensions that directly matter to customers: foundational safety and performance, speed of innovation, and long-term investment security.”

“CATL’s R&D depth and manufacturing quality control at gigawatt scale mean the cells inside the AG440 are engineered with the same rigour that powers millions of EVs. This translates into outstanding consistency, intrinsic safety, and a performance baseline that is extremely difficult for less-integrated competitors to replicate.”

The joint venture structure enables unprecedented development speed. “Because Ampace and CATL share a common DNA under the joint-venture structure, there is no technology wall between cell development and system integration. We move from joint cell specification to system deployment far faster than typical integrators, allowing us to combine, for example, -25°C cold start with 10,000-cycle longevity in a single product generation.”