Glassmaking needs lots of heat. Can electric furnaces provide it?

2025-10-21 09:14:45

Glassmaking has dramatically evolved in the thousands of years since ancient artisans crafted their first decorative beads and perfume bottles. But the underlying recipe remains virtually the same: Combine sand, sodium carbonate, and limestone, then blast the ingredients with scorching heat in a kiln or furnace.

Today, the vast majority of that heat is supplied by burning fossil fuels. Whether manufacturers are turning glass into windows, beverage bottles, smartphone screens, or coatings for solar panels, their methods require lots of energy to reach superhigh temperatures and, as a result, can be very carbon-intensive.

Global glassmakers in recent years have begun working to curb their emissions, spurred by environmental laws and the growing demand for low-carbon products. Companies are testing and deploying new furnace technologies that get their heat from electricity — not fossil gas or heating oil — or from alternative fuels such as hydrogen and biogas.

The latest of these emerging efforts comes from Bavaria, Germany, where multinational company Schott has recently started building a large electric melting pot at its existing factory in Mitrich. This storage tank is the first of its kind to produce glass types and quantities, and it will primarily rely on renewable energy from the power grid to convert materials into molten glass.

In 2022, global manufacturers produced over 150 million metric tons of glass. Although glass is used in many industries, its production scale is smaller than other carbon intensive materials. For example, cement production will exceed 4 billion tons in 2023, while steel production will approach 2 billion tons that year.

Nevertheless, glass manufacturing remains an important source of local air pollutants such as global warming gases and nitrogen oxides. The challenge of reducing these emissions is essentially the same as the challenge that troubles other heavy industries: figuring out how to achieve high enough temperatures to manufacture materials without warming the Earth in the process.

A glass melting furnace requires a temperature of 1200 to 1700 degrees Celsius (2192 to 3092 degrees Fahrenheit) - higher than lava - to liquefy raw materials and mix recycled glass.

It is more difficult to achieve complete electrification of facilities that produce large quantities of products such as container glass and windows. The existing electrical designs have been striving to operate with the same consistency and flexibility as gas stoves, and they cannot add as much recycled material to the glass mixture. Glass industry experts say that electric furnaces can also wear out and require replacement at a speed approximately twice that of gas furnaces.