# Capacitors and supercapacitors: What to track

Carbon prices, shallow grid markets and stronger hybrids

Source page: https://www.materialinsights.org/energy/e_supercaps/tracking/

What this tab covers The attributes worth tracking regularly, with the latest value, the direction of travel and why each matters.

Track cost per kW and per cycle, carbon feedstock prices, how fast grid markets pay for sub-second services, and the energy density of hybrids.

| Category | Attribute | Latest | Trend | Why it matters |
|---|---|---|---|---|
| Techno-economic | **LCOS trajectory** | USD 0.443/kWh-cycle baseline (2025 estimate, 45 s, 40 cycles/day)^[3](https://www.energy.gov/sites/default/files/2024-02/10_Technology Strategy Assessment -%2310 Supercapacitors_508_rev.pdf) | ↗ improving | DOE sees 23 to 26% cuts from R&D; value depends on cycles per day. |
| Techno-economic | **Capacity fade and state of health** | 1,000,000 cycles to 80% capacitance or 200% resistance^[1](https://www.skeletontech.com/hubfs/02-DS-2026-04-02-Skeleton-SCF3400%2c%20SCX5000-D60%20supercapacitor-1M.pdf?hsLang=en) | → stable | End-of-life is a clear, measurable test; ask for resistance growth data from field units. |
| Supply chain | **Critical material cost and geopolitical concentration** | Activated carbon about USD 15/kg; production in Japan and South-East Asia^[3](https://www.energy.gov/sites/default/files/2024-02/10_Technology Strategy Assessment -%2310 Supercapacitors_508_rev.pdf) | → stable | Materials are 71% of EDLC manufacturing cost; carbon needs to fall below USD 10/kg (DOE 2023, no newer public figure found). |
| Market | **Ancillary service market saturation** | Ancillary services under 5% of US wholesale market value^[7](https://liftoff.energy.gov/wp-content/uploads/2023/10/LIFTOFF_DOE_VVP_10062023_v4.pdf) | ↘ worsening | Fast-frequency markets are shallow and batteries compete for them; prices fall as capacity is added. |
| Regulatory | **Safety and environmental compliance** | UL 810A certification for Musashi lithium-ion capacitors (company); acetonitrile electrolyte flammable and releases hydrogen cyanide in fire^[4](https://www.bestmag.co.uk/hybrid-supercapacitors-solution-to-the-power-energy-tradeoff/)^[8](https://www.mdpi.com/2313-0105/10/2/54)^[9](https://cameochemicals.noaa.gov/chemical/11) | → stable | Lower runaway risk than lithium-ion may ease siting under codes like NFPA 855, but electrolyte hazards remain; watch shifts to propylene carbonate or ionic liquids. |
| Environmental | **Lifecycle carbon payback period** | No published figure found^[3](https://www.energy.gov/sites/default/files/2024-02/10_Technology Strategy Assessment -%2310 Supercapacitors_508_rev.pdf) | → stable | Ask suppliers for cradle-to-gate carbon per kW. |
| Environmental | **End-of-life route** | No industrial recycling rate published; electrode reuse shown in the laboratory (2024)^[10](https://leibniz-inm.de/publication/life-after-death-re-purposing-end-of-life-supercapacitors-for-electrochemical-water-desalination) | → stable | Without a recycling route, end-of-life costs fall on the owner. |
| Technology | **Hybrid (lithium-ion capacitor) energy density** | 65 Wh/kg, 50,000 cycles (Skeleton SuperBattery, company claim)^[2](https://energy-saxony.net/wp-content/uploads/2024/05/SkeletonTechnologies_CompanyIntro_2026.pdf) | ↗ improving | Higher energy density widens use from seconds to tens of minutes. |
| Market | **Grid-scale hybrid deployments** | 25 MW, 60 s supercapacitor section in the 500 MW / 1,000 MWh Jiayuguan NingSheng project, China, grid-connected 30 December 2025^[5](https://www.pv-magazine.com/2026/01/09/chinas-switches-on-worlds-first-gwh-scale-supercapacitor-energy-storage-project/) | ↗ improving | Shows utilities buying supercapacitors for inertia alongside batteries. |

#### Sources

1. [SCF3400 and SCX5000 D60 supercapacitor cell datasheet](https://www.skeletontech.com/hubfs/02-DS-2026-04-02-Skeleton-SCF3400%2c%20SCX5000-D60%20supercapacitor-1M.pdf?hsLang=en) Skeleton Technologies, 2026
2. [Skeleton Technologies company introduction 2026 (company presentation, hosted by Energy Saxony)](https://energy-saxony.net/wp-content/uploads/2024/05/SkeletonTechnologies_CompanyIntro_2026.pdf) Skeleton Technologies, 2026
3. [Technology Strategy Assessment: Supercapacitors (Energy Storage Grand Challenge, #10)](https://www.energy.gov/sites/default/files/2024-02/10_Technology Strategy Assessment -%2310 Supercapacitors_508_rev.pdf) US Department of Energy, Office of Electricity, 2023
4. [Hybrid supercapacitors: solution to the power-energy trade-off (trade press; manufacturer figures as reported)](https://www.bestmag.co.uk/hybrid-supercapacitors-solution-to-the-power-energy-tradeoff/) Best Magazine, 2026
5. [China switches on world's first GWh-scale supercapacitor-energy storage project (trade press, based on ESS News)](https://www.pv-magazine.com/2026/01/09/chinas-switches-on-worlds-first-gwh-scale-supercapacitor-energy-storage-project/) pv magazine, 2026
6. [Pathways to Commercial Liftoff: Virtual Power Plants](https://liftoff.energy.gov/wp-content/uploads/2023/10/LIFTOFF_DOE_VVP_10062023_v4.pdf) US Department of Energy, 2023
7. [Tuning of ionic liquid-solvent electrolytes for high-voltage electrochemical double layer capacitors: a review (Wang et al.)](https://www.mdpi.com/2313-0105/10/2/54) Batteries (MDPI), vol. 10, art. 54, 2024
8. [CAMEO Chemicals datasheet: Acetonitrile](https://cameochemicals.noaa.gov/chemical/11) US National Oceanic and Atmospheric Administration (NOAA), 2024
9. [Life after death: re-purposing end-of-life supercapacitors for electrochemical water desalination (Ren et al.)](https://leibniz-inm.de/publication/life-after-death-re-purposing-end-of-life-supercapacitors-for-electrochemical-water-desalination) Batteries and Supercaps, vol. 7, e202400506 (Leibniz Institute for New Materials), 2024

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_supercaps/index.md)
- [Overview](https://www.materialinsights.org/energy/e_supercaps/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_supercaps/correlation/index.md)
- [Science and technology](https://www.materialinsights.org/energy/e_supercaps/sg-sci/index.md)
- [Engineering and performance](https://www.materialinsights.org/energy/e_supercaps/sg-eng/index.md)
- [Economics](https://www.materialinsights.org/energy/e_supercaps/sg-econ/index.md)
- [Impact and additionality](https://www.materialinsights.org/energy/e_supercaps/sg-impact/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_supercaps/links/index.md)