(June 23, 2026) – STS today announced a new BESS battery cell lab testing service designed to help identify battery performance risks before supplier and production decisions are finalized. As one of the first companies in the industry applying battery cell testing this early in the project lifecycle, STS helps buyers evaluate long-term battery performance before large-scale manufacturing begins.
STS is launching this service as battery degradation receives increasing attention across the energy storage sector. Battery systems are commonly warranted to retain approximately 80% of original capacity after 10 years of operation, assuming annual degradation rates of roughly 2%. However, recent market observations indicate some systems may be degrading closer to 4% annually under real-world operating conditions.
The financial implications can be significant. For a 200 MWh project, an additional 2% annual degradation-related performance shortfall can contribute to estimated revenue losses of up to $15 million over a 10-year operating life.
STS applies battery cell testing before supplier and production decisions are finalized, helping buyers evaluate and verify battery performance assumptions that are embedded in contracts, manufacturing plans, and project financial models. By identifying degradation risks earlier, buyers can make more informed supplier and procurement decisions before those risks affect long-term project revenues, expected investment returns, and asset value.
Battery performance risks are often identified only during final factory acceptance testing (FAT) or after systems are already operating, when mitigation becomes more complex and costly. Issues identified during FAT can delay projects by weeks, while those discovered during site acceptance testing (SAT) can extend delays to months. STS evaluates battery cell performance under conditions aligned with real-world project operation, helping buyers assess degradation trends, validate supplier claims, and identify inconsistencies across manufacturing batches before shipment begins.
STS works exclusively on the buyer side, with no ties to manufacturers or testing laboratories. The company designs and manages battery cell testing programs through independent third-party laboratories, ensuring results are objective and aligned with project needs. Findings are translated into practical input for supplier selection, contract structuring, and investment decisions.
“Battery degradation is often viewed as a technical issue, but its impact is ultimately financial,” said Alexandre Minuzzo, CEO of STS. “When battery systems perform below expected levels, the effects can extend far beyond capacity loss, influencing project revenues, investment returns, and long-term asset value. Buyers need visibility into those risks before major project decisions are finalized.”
As battery storage matures as an asset class, long-term battery performance is becoming an increasingly important consideration in project financing, valuation, and investment decisions. STS’s new service reflects this shift, helping buyers assess performance risks before they can translate into unexpected revenue losses and other long-term financial impacts.
###
About STS
In today’s renewable energy market, risk is no longer demand, it’s execution. STS protects investors from that risk. STS is an independent technical advisory and quality assurance firm and ISO/IEC 17020-accredited inspection body, providing buyer-side expert support throughout the solar PV and energy storage procurement cycle. With 16 years of experience, STS supports leading global developers, investors, and asset owners, ensuring what is promised is de-risked, delivered, bankable, and economically optimized.