High-temperature batteries: What to track
Spare parts for old fleets and the fate of ZEBRA cells
What this tab covers The attributes worth tracking regularly, with the latest value, the direction of travel and why each matters.For NaS, track how the legacy fleet is supported now that NGK has stopped selling. For ZEBRA, track whether new developers reach commercial production.
| Category | Attribute | Latest | Trend | Why it matters |
|---|---|---|---|---|
| Techno-economic | LCOS trajectory | No independent NaS or ZEBRA LCOS found for 2024-2026; US lithium-ion 4 h benchmark USD 210-292/MWh (Lazard, Jul 2026)113 | ↘ worsening | Lithium-ion cost falls removed NaS's cost advantage at 6 to 8 hours. |
| Technical | Capacity fade and state of health | Below 1% a year (2024 NaS product); 7,300 cycles or 20 years rating110 | ↗ improving | Ratings rose from 4,500 cycles and 15 years in earlier products. |
| Supply chain | Critical mineral cost and geopolitical concentration | Sodium and sulphur abundant; nickel for ZEBRA about 67% from Indonesia (calculated, 2025)12 | → stable | Materials risk is low; supplier concentration is the bigger issue. |
| Market | Ancillary service market saturation | NaS responds in about 1 ms but most frequency markets are being filled by lithium-ion10 | ↘ worsening | Revenues from fast services are being competed away. |
| Regulatory | Safety and environmental compliance | UL 1973 component recognition and UL 9540A evaluation; EU battery passport for industrial batteries above 2 kWh from 18 Feb 20272314 | → stable | Post-2011 upgrades; BASF reported no further NaS incidents up to 2023 (company statement). |
| Environmental | Lifecycle carbon payback period | No figure found in sources reviewed | → stable | Heater energy and steel content drive the footprint. |
| Corporate | Supplier continuity (technology-specific) | NGK board decided on 31 Oct 2025 to stop NaS manufacturing, sales and new orders; maintenance parts continue. Altech CERENERGY factory abandoned Jul 2026118 | ↘ worsening | Owners of NaS fleets depend on NGK parts support for the remaining life; no new commercial-scale ZEBRA-type supplier has emerged in Europe. |
| Technical | Heating losses in standby (technology-specific) | ZEBRA overall efficiency 70.7-71.8% in peak shaving vs 80.9% on full cycles6 | → stable | Idle time eats efficiency; utilisation determines value. |
Sources
- Japan's NGK discontinues manufacturing of sodium-sulfur batteries (5 Nov 2025) pv magazine / ESS News, 2025
- NAS Battery: product sheet (container specifications and references), dated 02/2024 BASF Stationary Energy Storage, 2024
- Sodium Sulfur Batteries NAS for Large Stationary Storage Applications: The time is right! (F. Dötz, NAATBatt Sodium Zinc Battery Workshop, Houston, 30 Nov 2023) BASF Stationary Energy Storage / NAATBatt, 2023
- Evaluating ZEBRA battery module under the peak-shaving duty cycles (Shamim et al., Materials 14(9) 2280) Pacific Northwest National Laboratory, 2021
- NGK's NAS sodium sulfur grid-scale batteries in depth Energy-Storage.news, 2016
- Mineral Commodity Summaries 2026: Nickel US Geological Survey, 2026
- Lazard's Levelized Cost of Energy+ (LCOE+), July 2026 (LCOS v11.0 key assumptions p. 38; LCOE v19.0 assumptions p. 28) Lazard, 2026
- SafeGuardS 115/23: EU issues new regulation on batteries and waste batteries (summary of Regulation (EU) 2023/1542) SGS, 2023
- Altech stellt Cerenergy-Batteriefabrik in Schwarze Pumpe ein (Altech halts CERENERGY battery factory, 5 Aug 2026) CleanThinking, 2026