# Polysilicon: Emissions

Why coal power makes polysilicon a carbon-heavy material

Source page: https://www.materialinsights.org/chemicals/polysilicon/emissions/

What this tab covers The greenhouse-gas footprint per tonne, split by lifecycle phase (feedstock, production, movement, use, end of life), the global total, other environmental impacts, levers and low-carbon routes, India's position, and where the investment opportunity lies. Emission intensity 35.0 t CO2e per t range about 10 (hydro-powered) to about 45 (coal-powered Siemens) · derived: Siemens about 48 kWh/kg x about 0.6 kg CO2/kWh (about 29 t) plus silicon metal at about 11 t CO2e/t x 1.1 t (about 12 t) and steam; FBR about 20-25 t; weighted 76/24 Global emissions per year 50.0 Mt CO2e per year 2025 · about 35 t x about 1.43 Mt

Per t of solar-grade polysilicon, cradle-to-gate. Intensity: China Polysilicon 2026 report (power use; 0.6 kg CO2 per kWh sensitivity); silicon tile; derived (indicative). Global total: derived (indicative).

#### Share of footprint by lifecycle phase
 Feedstock 34% Production / process 63% Movement 3%

#### Footprint by lifecycle phase

| Phase | Intensity | Share | Main sources of emissions | Notes | Source |
|---|---|---|---|---|---|
| **Feedstock** | about 12 t CO2e per t | 34% | silicon metal from coal-fired arc furnaces (about 11 t CO2e per t Si) | 4-5 t on Norwegian hydro (silicon tile) | silicon tile (derived, indicative) |
| **Production / process** | about 22 t CO2e per t | 63% | electricity for deposition and hydrogenation (48-55 MWh/t Siemens, 11-20 FBR); steam | each 1 kWh/kg saved is about 0.6 kg CO2/kg | China Polysilicon 2026 report |
| **Movement** | about 1 t CO2e per t | 3% | silicon metal and polysilicon transport within China and by sea | Indicative | Indicative |
| **Use** | not applicable | – | solar panels made from it avoid far more emissions over 25-30 years than their manufacture emits | Avoided emissions counted at the power system level | Not applicable |
| **End of life** | not published | – | module recycling recovers glass and aluminium; silicon recovery is small | Indicative | Indicative |

#### Other environmental impacts

Chlorosilane and HCl safety; forced-labour concerns in Xinjiang (Conway 2023; US UFLPA); large water use (about 8 t per t for Siemens).

#### Levers to cut emissions

- Switch Siemens to FBR (11-20 vs 48 kWh/kg)
- Run plants on hydro, solar or wind power
- Low-carbon silicon metal (hydro, charcoal reductants)
- Reactor efficiency: leaders below 40 kWh/kg, ceiling about 35

#### India

India has no polysilicon output; new plants on coal-heavy Indian grid power would emit about 35-45 t CO2e per t unless paired with dedicated renewables (derived, indicative).
 Emission figures are indicative global averages from the life-cycle studies named; actual footprints vary widely by site, energy mix and method.

#### Low-carbon routes

| Route | Intensity | Cost premium | Status | Source |
|---|---|---|---|---|
| **FBR granular on clean power** | about 15-20 t CO2e per t on grid; under 10 t on hydro (derived, indicative) | none; lowest cash cost (GCL RMB 25.31/kg) | GCL 480 kt; Tongwei 10 kt FBR pilot | China Polysilicon 2026 report; PV Tech (Apr 2025) |
| **Hydro-powered Siemens (Wacker, Sichuan and Yunnan plants)** | about 10-15 t CO2e per t (indicative) | higher in Europe; low in Chinese hydro provinces | Wacker Burghausen; Chinese plants in Leshan and Yunnan | Conway (2023); indicative |

 For a climate investor Polysilicon is India's largest missing link in solar manufacturing. The ALMM wafer mandate from June 2028 creates protected demand, and MNRE is preparing a PLI for more than 10 GW of polysilicon, though its size and terms were not public by October 2026. China has over 3.2 Mt of capacity running at about 40% and prices near RMB 32/kg in mid-2026, so an Indian plant only works with low-cost round-the-clock renewable power, FBR or best-in-class Siemens technology, and policy that holds for a decade. Clean power would also cut the footprint from about 35-45 t CO2e per t on the Indian grid to roughly 10-15 t, which may earn a premium in EU and US markets. Watch Adani (2028 target), Reliance (Jamnagar) and the PLI's final terms.

## Other sections

- [Summary](https://www.materialinsights.org/chemicals/polysilicon/index.md)
- [Overview](https://www.materialinsights.org/chemicals/polysilicon/overview/index.md)
- [Correlation](https://www.materialinsights.org/chemicals/polysilicon/correlation/index.md)
- [Production route](https://www.materialinsights.org/chemicals/polysilicon/routes/index.md)
- [Production](https://www.materialinsights.org/chemicals/polysilicon/production/index.md)
- [Feedstocks](https://www.materialinsights.org/chemicals/polysilicon/feedstocks/index.md)
- [Cycles](https://www.materialinsights.org/chemicals/polysilicon/cycles/index.md)
- [Trading](https://www.materialinsights.org/chemicals/polysilicon/trading/index.md)
- [Movement](https://www.materialinsights.org/chemicals/polysilicon/movement/index.md)
- [Regulation](https://www.materialinsights.org/chemicals/polysilicon/regulation/index.md)
- [Characteristics](https://www.materialinsights.org/chemicals/polysilicon/characteristics/index.md)
- [Relationships](https://www.materialinsights.org/chemicals/polysilicon/links/index.md)