/daily ·29 JUL 2026 ·WEDNESDAY ·2 MIN READ ·6 STORIES

Wednesday, 29 July — Sodium-ion arrives; Australia breaks records

CATL's sodium-ion grid storage gets its first real container-level specs. Australia's battery fleet hits 9,000 MW as price arbitrage margins collapse — which is, counterintuitively, the market working correctly.

01 / The Day

WEDNESDAY 29 JUL 2026, ranked

CATL sodium-ion Tener container: ~200 kWh/m³ density, ~$52/kWh system cost

Energy Storage News published a detailed analysis of CATL's sodium-ion Tener grid-storage container specifications, showing approximately 200 kWh/m³ energy density and a reported system cost near $52/kWh — the first container-level sodium-ion specs publicly disclosed by a major manufacturer.

Why it mattersSodium-ion reaching container-level density parity with mature LFP at sub-$60/kWh is the datapoint the chemistry has needed to move from promising laboratory result to deployable grid product.

01 energy-storage.news↗

Australia's grid-scale BESS fleet crosses 9,000 MW as battery price spreads fall 85%

Australia's National Electricity Market grid-scale battery fleet exceeded 9,000 MW installed capacity, while battery arbitrage price spreads — the margin between buying cheap and selling dear — have fallen 85% year-on-year as the fleet grows.

Why it mattersSpread compression is the self-defeating success condition of battery arbitrage: more batteries reduce the price volatility that makes arbitrage profitable. The fact that Australia is still building suggests grid operators are now procuring storage for ancillary services, not just arbitrage.

02 energy-storage.news↗

Neoen breaks ground on 907 MWh grid-forming battery in South Australia

Neoen began construction on a 907 MWh grid-forming battery energy storage system in South Australia — among the largest grid-forming BESS projects to enter construction globally, designed to supply synthetic inertia as coal and gas generators retire.

Why it mattersGrid-forming storage is qualitatively different from arbitrage batteries: it provides the frequency regulation that spinning generators supply, which is what utilities actually need to keep high-renewable grids stable.

03 energy-storage.news↗

Tesla takes 90% stake in 509 MW Arizona solar and storage project

Tesla acquired a 90% stake in a 509 MW solar farm with co-located battery storage in Arizona under a power purchase agreement with developer Sterling, securing long-term clean power supply for its own operations.

Why it mattersA 509 MW solar acquisition is a meaningful fraction of what a large factory or data centre campus consumes annually; Tesla is treating energy as a balance-sheet asset rather than an operating expense, a different financial posture from most industrials.

04 electrek.co↗

Polish researchers achieve 21.87% efficiency in semi-transparent perovskite solar cell

Polish scientists built a semi-transparent perovskite solar cell achieving 21.87% conversion efficiency — a significant result for the wide-bandgap top cell in a tandem architecture, where transparency requirements normally impose a hard efficiency penalty.

Why it mattersSemi-transparent perovskite cells are the bottleneck in scaling perovskite-silicon tandems; this efficiency at meaningful transparency relaxes the design trade-off constraining tandem modules below lab efficiency records.

05 pv-magazine.com↗

OCI Holdings to double polysilicon production capacity by 2029

OCI Holdings, one of the world's largest polysilicon producers, announced plans to double its solar-grade polysilicon manufacturing capacity, targeting completion by 2029.

Why it mattersPolysilicon supply was the constraint that amplified the 2021-2022 solar cost spike; doubling capacity from a major non-Chinese producer is a structural supply-chain move that will affect Western module pricing through the rest of the decade.

06 pv-magazine.com↗

Be subscriber #012 the weekly ten, every friday by email · no spam · unsubscribe anytime

Past days

The Daily Archive

/SAT 01 AUGThe Heat Is the Story /FRI 31 JULCalifornia hits 51% monthly solar; China sets record targets /THU 30 JULThe Billion-Dollar Build Edition /WED 29 JULWednesday, 29 July — Sodium-ion arrives; Australia breaks records /TUE 28 JULMalaysia orders the grid; Australia scales the cell /MON 27 JULA Solar Farm Becomes a Data Centre, Wisconsin Campaigns Against Solar, and LONGi Breaks the Tandem Efficiency Record /SUN 26 JULThe Build-Out Accelerates /SAT 25 JULUS battery storage breaks Q1 record; China tightens polysilicon /FRI 24 JULShock and Shine /WED 22 JUL194 gigawatts and a record solar cell /TUE 21 JULStorage everywhere, blockages everywhere /SUN 19 JULTwo US LFP milestones, one weekend /SAT 18 JULOvercapacity meets the taxman /FRI 17 JULFriday in Energy: Sodium Scales, Silicon Shines /WED 15 JULRecords fall, costs diverge /MON 13 JULSolid-state gets a quality stamp /SAT 11 JULThe grid just got bigger /FRI 10 JULSodium, Zinc, and CO2: Storage Diversifies Its Chemistry /THU 09 JULThe grid bottleneck, the cell plant, and the inverter ban /WED 08 JULLDES lands, sodium-ion signs 60 GWh, and US solar manufacturing hits 3 GW /TUE 07 JULSodium Goes Commercial