The California and Council of Science and Technology has released the next in its series of studies documenting the technology required to meet radical greenhouse gas (GHG) emission cuts by 2050 (80 percent below 1990 levels).

This report focuses on strategies for reducing energy use and greenhouse gas emissions through energy-efficient technologies and retrofits of the residential and industrial sectors.

"We found that although we couldn't solve the entire GHG problem through efficiency alone, we expected that outcome. On the positive side, we were able to conclude that although it will be very challenging, substantial levels of additional efficiency and electrification in buildings and industry are possible, with large GHG benefits," says lead author Jeffery Greenblatt, a staff scientist in the Environmental Energy Technologies Division (EETD).

Because population and economic growth are projected to roughly double the total demand for energy services by 2050, achieving 80 percent GHG reduction from 1990 levels actually requires a 90 percent reduction from 2050 emissions if nothing is done (the business-as-usual case).

For the residential and commercial buildings sector, the research team examined the savings achievable through four categories of efficiency improvements: reduced capacity (down-sizing, such as smaller refrigerators, or space conditioning one room rather than the whole building), increased efficiency (often through new technology), reduced usage (a combination of technology-facilitated control and behavior change), and system integration (combining elements of several service categories).

They found that although it was possible to reduce energy use technically to meet California's 80% GHG reduction goal in the residential and commercial buildings sector, the potential is limited by economic feasibility and finite rates of implementation.

However, the report's analysis provides guidance to the policy community on which energy efficiency strategies, combined with other greenhouse gas reduction policies in transportation, renewable energy, and electrification might move the state more rapidly towards its goal.

By looking at the rate of new construction, retrofit and demolition, and estimating the energy efficiency improvements that are typical of existing homes, the report concludes that a 40 percent efficiency savings is possible in the 2050 California building stock relative to 2010 for both the residential and commercial sectors.

In the area of industrial energy efficiency, the research team estimated that the potential for a 48% overall reduction in energy use relative to BAU was possible by 2050.

The analysis included a detailed examination of the oil and gas refining (60% of industrial energy use) and the food industry (17% of energy use), for which extensive data are available. They assumed that oil demand decreases substantially by 2050, replaced by large-scale vehicle and building electrification and the increased use of biofuels.

For other industrial sectors, the research team looked at similar processes (e.g., boiler systems, process heating, motor systems) for savings potential based on commercially available technologies, and then estimated the fraction of total industrial activity involving that process by industry sector.

The study does not examine policies that can realize these reductions in emissions-that is the subject of another study now in progress called California's Energy Future Policy.

The report's authors are Jeffery Greenblatt, Max Wei and James McMahon of Lawrence Berkeley National Laboratory (Berkeley Lab).