Current Technology Could Reduce Global Energy Demand by 85%

The world could reduce its energy demand by 85% using current technology, according to a new theoretical study by researchers at the University of Cambridge (Environ. Sci. Technol. DOI: 10.1021/es102641n).

The quest to solve global energy problems often focuses on improving the energy supply, such as by building wind farms or growing crops for biofuels. The new study highlights options for cutting the amount of energy that is needed in the first place, says lead author Jonathan M. Cullen, a research associate in the engineering department at Cambridge.

Cullen's team began the study by examining how much energy could be saved by improving the design of passive systems in buildings, vehicles, and industrial equipment, such as the furnaces used to melt iron ore for steel production. A passive system, such as a building's insulation or a vehicle’s shape, does not require external mechanical power to operate.

Implementing better designs in passive systems can produce significant energy savings, Cullen says. For example, German and Swedish researchers developed an energy-efficient building design standard called Passivhaus. Buildings that meet the standard trap heat from the sun and are so well insulated that they require little energy to heat, even in cold climates. As a result, a Passivhaus design can reduce heating energy costs by as much as 90%, according to the Passive House Institute U.S., a consulting and research organization that certifies the building standard in the U.S.

To study how much similar design changes would affect global energy demand, the Cambridge team used a model that they had developed during earlier research to follow energy flow from raw fuels through their use in transportation and in the production of heat and light. The researchers added data on conservation from design changes and current energy consumption to calculate how much energy the world could save.

They found that implementing the best available design improvements to passive systems in every building, factory, and vehicle would reduce world energy demand by 73%. When they added potential gains from some energy-efficient active systems such as light bulbs, appliances, and engines, they calculated that as much as 85% of energy demand could vanish.

"This is absolutely a best-case scenario," Cullen cautions. "It assumes we could put the best-known technologies in every application globally, and do it right now."

But Kornelis Blok, a professor of sustainable energy at Utrecht University in the Netherlands, says the new study demonstrates the enormous potential for reducing energy demand: "It shows what is ultimately possible."

To encourage the implementation of energy-saving technologies, governments need to enact new regulations and incentives, Blok says.

Even if such carrots and sticks existed, achieving significant demand reductions would take time. Currently, only about a dozen buildings that meet the Passivhaus standard have gone up in the U.S. It would likely take between 50 and 100 years to replace every home worldwide with a building that meets the standard, Blok estimates.

Meanwhile, the U.S. Energy Information Administration projects that world energy consumption will continue to grow by 1.4% annually, reaching 739 quadrillion Btu in 2035.

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