Don't disturb the neighbors when you retrofit.

Legions of contractors have said that to homeowners when considering a makeover. Industrial manufacturers might start hearing the same message more often.

In an interesting case study, Dubai Aluminum, or Dubal, is retrofitting a series of company-owned gas turbines rather than replacing them with new models. When the project is completed in 2012 or 2013, the 1 gigawatt of capacity Dubal had before the retrofit will, ideally, be expanded to by 100 megawatts, allowing it to increase output. The retrofitted turbines will also reduce NOx fumes buy 15 percent and cut fuel consumption by $4 million annually.

The entire project might end up costing $45 million, but adding 100 megawatts of capacity to the existing plant the more traditional way – when the cost of permitting, construction and other factors are added – might have come to $120 million, according to Anne McEntee, general manager of power services in the energy services division at General Electric, which oversees the project.

"Power is approximately 30 to 40 percent of the cost of manufacturing aluminum," she said. "Some of the rotors are at end-of-life anyway. Some have spun 250,000 hours."

But even a more prominent motive for future industrialists may lay in the uncertainty surrounding land use and emissions regulations. New construction typically has to pass through a gauntlet of administrative and legal hearings before the first shovel of earth can be turned. In a retrofit, the administrative burdens are lower if a company can remain inside of its existing limits for emissions, water consumption and other factors.

"Ten years ago, permitting may have been simpler because everything was about creating jobs," she said. "Now, we're seeing more and more people ask, 'What can I do with my existing footprint?' "

In California, GE is retrofitting an oil production plant and is also in the midst of assignments in Canada, South Africa and Algeria.

Although not as cheap as swapping out incandescent bulbs, industrial modernization will likely occupy a prominent part in the debate on energy efficiency and carbon emissions at Copenhagen and other policy meetings. Energy efficiency improvements at the industrial level could ultimately account for 40 percent of the efficiency gains that could be achieved by 2020, according to a report from McKinsey & Company. In the U.S., industrials consume 19.3 quads of end-user electrical power (power consumed at a plant or inside a building) and 27.2 quads of primary power (power consumed locally, but also power lost during transmission and conversion).

End-user power could drop to 16.9 quads by 2020 and 22.4 quads for primary power with the right measures. Without efficiency measures, the numbers could climb to 20.5 and 28.3 quads respectively. Right now, the U.S. consumes 36.0 quads of end-user power and 64.7 quads of primary power, according to the report. (In all, the U.S. consumes 100 quads of energy from all sources and dissipates 55 to 60 quads unproductively, according to Arun Majumdar, the Lawrence Berkeley scientist who recently took over ARPA-E.)

And this just represents the U.S. where manufacturing is efficient and on the wane.

Retrofits are actually somewhat on the expensive side, according to the McKinsey report. Managing the energy consumption of intensive, better electric motors and waste heat recovery systems would all be cheaper.

Retrofitting gas and steam turbines accounts for around $700 million a year in revenue for GE, but the figure will likely grow, McEntee stated.

Can retrofitting cannibalize sales of new turbines? That's a distinct possibility. The dollars behind retrofit contracts are also generally lower. On the other hand, retrofits invariably prevent competitors from wooing away an existing account.

"It's more of a long-term engagement," she said.