Industrial Systems

Within world industry, about 49% of onsite energy is lost to waste and inefficiency ¹. Systemic changes in the structure of manufacturing plants can reduce these losses.

Sources: the Building Energy Codes Program ², Elson et al. ³, Global Energy Assessment ¹, Hedmon et al. ⁴, IEA ⁵ and ⁶, the Department of Energy ⁷, UN Environment ⁸, UNIDO ⁹.

Benchmarking

Benchmarking is the practice of measuring the energy performance of plants across an industry and setting the best performing plants as a standard. As of 2010, there is an estimated potential of 23-31 exajoules of energy savings through benchmarking, mostly in low-income countries ⁹. The International Energy Agency estimates that applying benchmarks to the G20 countries can save nearly half the energy in the iron and steel sectors and about 15% of energy in cement manufacture ¹⁰. Lu et al. ¹¹ estimate that Taiwan could save 5.3% of national energy usage by applying benchmarks in the six most energy-intensive industries in the country, while Shabbir, Mirzaeian, and Sher ¹² estimate that Pakistan could save 43% of energy consumption in the pulp and paper industry by applying benchmarks from the UK and Canada.

Benchmarking programs such as the Superior Energy Performance (SEP) can show financial payback times of less than two years ¹³.

Rogers, Cooper, and Norman ¹⁴, focusing on the paper and pulp industries, caution that benchmarking may be of limited use to individual plants because of differences that particular plants might have, in processes, markets, and other factors, from the industry average.

Motor and Steam Systems

Motor systems use 10,700 TWh of electricity each year, of which 5700 TWh are used by industrial motors ⁸. Their efficiency will increase by an estimated 14% by 2040 under business as usual, or by 35% under accelerated efficiency policies ⁵. In 2023, the Energy Efficiency Movement estimated that after seven years, there is a potential for a reduction of 300 million tons of carbon dioxide per year, a bit less than 1% of total world emissions ¹⁵. Some of the larger sources of energy savings in motors are the use of variable speed motors ¹⁶ and load-based voltage control ¹⁷, which adjusts voltage based on load, saving energy particular for motors with low load factors.

There is an estimated savings potential of 8.8 exajoules per year from steam system energy based on 2005 usage ¹. These savings can be realized at a cost of 1.4 to 14.4 ¢/kWh ¹⁸. A 2024 case study ¹⁹ of a Moroccan pulp and paper mills finds that 6% of energy consumed in steam systems could be saved with measures with short payback periods.

Combined Heat and Power

Conventional thermal power systems waste much heat and operate with an efficiency of about 45%, whereas a combined heat and power (CHP) system generates electricity and captures exhaust heat for direct use. The combined system operates with efficiencies of 65-75% ²⁰, up to 89% ²¹. We estimate a technical potential of about 75 GW additional CHP capacity in the United States ⁷, of which about half should be economically viable ⁴.

Conversely, high temperature waste heat from industrial processes can be recovered for electricity production. The United States has a technical potential of 8,840 MW from waste heat to power (WHP) systems, of which 2,904 MW should be accepted by the market ³.

As of 2019, more than 99% of primary energy behind CHP systems were fossil fuels, with more than half of the energy from coal ²². Clean hydrogen ²³ is an alternative factored by the CHP industry.