Glass Melting Technology: A Technical and Economic ... - OSTI

consumption level was 5.5 GJ (6.9–7.7mmBtu/short tons) per ton of molten container
glass in Europe.
Glass furnace energy consumption includes the fuel input of the melting furnace,
electricity for boosting, oxygen for firing the furnace, (primary energy, including electric
energy of one (1) kWh/MJ and oxygen consumption of one (1) m 3 oxygen, is 0.33–0.36
MJ). These figures do not include the energy consumption of downstream devices, i.e.,
distributors, forehearths, etc., and air pollution equipment. Comprehensive statistics for
glass melting energy of glass furnaces in the United States have been difficult to obtain.
(See Figure I.2. for Energy Consumption of 123 Glass Furnaces.)
Figure I.2. Energy consumption of 123 glass furnaces globally, ranked low to high.
Financial models that justify development of technology and capital investment for
energy reduction make assumptions about future cost of energy. However, future cost
and availability of energy is uncertain. The underlying assumption of these financial
models, usually not explicitly stated, is that the energy needed will be available in the
quantity and form the technology requires. Energy has been readily available during the
past 25 years, and the “Annual Energy Outlook” of the Energy Information
Administration in the US Department of Energy forecasts relatively low energy cost
escalation to 2025. (Editor’s Note: Given recent developments (2004), this forecast is
now questionable). Value of the energy saved at the current cost of energy with an
assumed low rate of cost escalation is insufficient to justify many energy-saving
technologies, particularly technologies that require significant capital investment.
Increased volatility in some energy prices, such as natural gas, may cause some glass
manufacturers to consider alternative scenarios for future energy. In consultation with
glass industry experts over the effects of energy costs three to five times greater than the
current energy costs, we conclude that if forecasts of the future were to predict significant
increases in energy costs, the glass industry’s interest in developing energy-saving
technologies, or alternative energy sources, would increase dramatically. Without
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