Watt Matters: The BESS Revolution, with Swetha Sundaram

Battery energy storage systems (BESS) have rapidly evolved from a niche technology into a core pillar of the modern renewable grid. As utility-scale solar expands, storage is no longer a “nice-to-have”—it’s essential for delivering reliability and resilience. In this episode of Watt Matters, Ana speaks with Swetha Sundaram, VP of Solar and Hybrid BESS Systems at RWE Clean Energy and co-author of The BESS Book, to unpack what’s driving this transformation.

Swetha shares her insider’s perspective on the evolution of storage—from early pilot projects to today’s 200MW+ systems—and offers practical insights into permitting, design, safety, and revenue optimisation. She also explores how AI and emerging chemistries are reshaping what’s possible for grid-scale storage, and why collaboration across communities and regulators is key to BESS success.

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Takeaways
BESS has become a critical part of grid infrastructure, not just a solar add-on.

Safety and permitting remain top challenges, requiring proactive community engagement.

Lithium iron phosphate (LFP) chemistry now dominates for cost and safety advantages.

Project scale has increased from 10MW a decade ago to 200MW and beyond.

AI and predictive analytics are unlocking smarter battery degradation management.

Revenue realisation depends heavily on sophisticated software and dynamic dispatch.

Permitting delays can be avoided by early collaboration with local authorities.

Standalone storage is thriving post-IRA, enabling new grid and data centre applications.

Long-duration technologies like sodium-ion and iron-air show strong future potential.

The future of BESS lies in integration—across grids, industries, and digital systems.

Chapters
00:00 – Introduction and guest background
03:00 – Why BESS matters for the clean energy transition
06:00 – Writing The BESS Book and its intended audience
09:00 – What is BESS and how it works
12:00 – How technology, chemistry, and safety have evolved
15:00 – Permitting challenges and lessons learned
18:00 – The unique development and operational aspects of BESS
24:00 – Market dynamics, tariffs, and project economics
29:00 – The rise of standalone storage and data centre integration
33:00 – The role of AI in optimising storage performance
39:00 – Long-duration storage and emerging technologies
43:00 – Hard-earned lessons and key takeaways for developers
47:00 – The future of storage and closing thoughts