Volta Hybrid Furnace Cuts Flat Glass Carbon Emissions

The Volta pilot furnace operates with a 50 per cent share of electricity and the remaining energy supplied through a combination of oxygen and gas. The technology is designed to reduce fossil-fuel use and carbon emissions from flat-glass production, one of the industrial sectors that has traditionally relied heavily on natural gas.

The furnace is located at AGC’s Barevka plant in Dubí, near Teplice, Czech Republic. AGC and Saint-Gobain began the project by rebuilding an existing patterned-glass production line, with the pilot inaugurated in February 2025.

After one year of operation, the companies said the furnace had maintained stable production while meeting design expectations for energy consumption, temperature control and glass quality. Tests covered different recycled-glass, or cullet, ratios and production rates.

The key difference is how the furnace supplies heat. Conventional flat-glass furnaces are predominantly natural-gas fired, while the Volta design combines electric melting with oxy-gas combustion. The project was developed as a proof of concept for technology that could eventually be adapted to larger industrial float-glass furnaces.

The technology has also increased the amount of recycled glass used in the process. Saint-Gobain said standard operation at the Volta furnace uses 88 per cent cullet, compared with 40 per cent previously. Higher cullet use reduces the amount of raw material that needs to be melted and can lower the energy required for production.

According to Saint-Gobain, the combination of hybrid melting, a 50 per cent electricity share and higher cullet use reduced fossil-fuel consumption by 66 per cent compared with the project's reference case. The company also reported a 71 per cent reduction in Scope 1 and Scope 3 carbon dioxide emissions under the Innovation Fund accounting methodology used for the project.

Those figures come with an important qualification. The reported emissions comparison is against a defined reference covering emissions associated with gas and raw materials, rather than a claim that every flat-glass furnace could immediately achieve the same reduction. Large-scale deployment would also require substantial investment, while the companies continue to assess the most cost-effective balance between electricity and gas.

The project matters because flat glass is used across construction, transportation, furniture and technology applications, creating a large industrial demand for high-temperature melting. The European Commission’s Climate, Infrastructure and Environment Executive Agency has described the Volta project as an effort to develop a lower-carbon pathway for an industry that is difficult to decarbonise.

The European Union Innovation Fund supported the research and development project. AGC and Saint-Gobain have positioned the pilot as a technology demonstration rather than an immediate replacement for the industry's existing furnace fleet.

The first year has also provided evidence that hybrid melting can maintain commercial-quality glass production while changing the energy mix. AGC and Saint-Gobain said the results strengthened their confidence in scaling the concept to future industrial applications.

For the glass industry, the next challenge is moving from a successful pilot to economically viable large furnaces. The companies said the coming development phases will focus on industrial-scale deployment and on balancing electricity and gas costs.

The Volta furnace therefore represents a test of whether heavy industry can reduce fossil-fuel dependence without changing the basic quality and reliability requirements of flat-glass manufacturing. Its next stage will determine whether the technology can move beyond demonstration and into wider industrial use.