Americans spend most of their lives inside some of the biggest energy hogs on the planet, and it's not their automobiles.

Commercial and residential buildings consume 40 percent of all the nation's energy, and 70 percent of all electricity, according to the U.S. Department of Energy. In 2009, the department estimates that residential buildings will gobble up 22 percent of the country's total energy with commercial buildings using about 18 percent. Additionally, buildings account for about 40 percent of the total U.S. carbon emissions.

To change those energy-wasting habits, UC researchers are "re-educating" buildings to conserve power and reduce pollution. Through synergistic relationships with government agencies, private entrepreneurial companies and end users committed to a greener built environment, UC researchers are rapidly bringing new technologies into the marketplace.

"Most economic and technical analyses suggest that buildings offer one of the best opportunities, if not the best, to economically and rapidly reduce energy demand and limit greenhouse gas emissions," Arun Majumdar, director of Environmental Technologies Division at the Lawrence Berkeley National Laboratory, said during his recent testimony before the U.S. Senate Committee on Energy and Natural Resources.

UC innovations are making the most of those opportunities, saving money, fighting global warming and at the same time transforming the construction and retrofitting of homes and commercial buildings. And UC discoveries are among the most promising for creating the ultimate zero-net energy building, one that produces enough on-site renewable energy and system efficiencies to offset the energy consumed from the power grid.

Next generation lighting

At UC Davis, the California Lighting Technology Center is pioneering a daylight harvesting system that could save millions of dollars for big box retailers and other large commercial building tenants. The center has licensed the technology to two companies, Watt Stopper/Legrand and Axis Technologies. Watt Stopper is currently testing the system at a West Sacramento Wal-Mart.

"Daylight harvesting has been one of the most promising technologies," said Konstantinos Papamichael, associate director of the lighting center.

Systems that adjust a building's interior lighting to take advantage of natural light coming through windows and skylights have been in use but they're expensive, said Papamichael. The current systems need to be recalibrated every time the interior environment changes. That involves a lighting technician coming to the building and methodicially recalibrating the lights to adapt to changing conditions.

"With our system, you just go under the skylight, connect it and the magic happens," he said.

Manual recalibration can be costly for a retailer especially whose interiors frequently change with seasons and sales. At Wal-Mart, for example, Papamichael said, when the test of the UC Davis system began the dark red and green merchandising displays of Christmas filled the space. After the holidays, the white shelves were more visible. A lesser lighting system would have been fooled into thinking there was more daylight available and dim the interior lights. The UC Davis system uses two sensors, rather than the one-sensor system now commercially in use. One sensor points to the interior and the other through the skylight. The system uses information from both sensors to automatically adjust the lighting.

"We've increased energy savings for Wal-Mart, and we've proved that it works," said Papamichael, who expects demand for the system to increase when new California energy efficiency building codes go into effect in August.

The light harvesting system is just one product under development at the lighting center, which was established by the California Energy Commission's Public Interest Energy Research program. The center's main focus is to solve real world problems and bring those solutions to market as quickly as possible working with industry partners who have access to customers.

Transforming the marketplace

When the New York Times went looking for a way to reduce energy costs for its new 51-story Manhattan headquarters building, nothing on the market in 2003 met its requirements or budget. The Times needed something compatible with the design of its sleek, new architectural monument, which features a transparent, glass curtain wall. But it also needed something to control the glare of the light streaming in and the heating and cooling effects of the large walls of glass. The Times turned to the Berkeley Lab's Environmental Energy Technologies Division.

"We had been doing research on these smart lighting controls for a decade," said Eleanor Lee, co-principal investigator on the Times project. "This collaboration led to a significant leap forward in the concept of façade systems. We look at pilot demonstrations that can help to accelerate products to the market. These dynamic façade systems are what we think are going to transform the market."

The Times system includes computer-controlled shades that respond to seasonal and time-of-day daylight changes and dimmable lighting. The lab innovations allowed the Times to overcome the downsides of glare and occupant discomfort but still take advantage of building with glass walls to maximize daylight and save lighting costs. The lab's work also forced the marketplace to adopt a new generation of green technology.

Vendors typically shy away from manufacturing systems they consider so specialized they won't be profitable for mass markets, said Lee. But with the high-profile Times project and the massive scale of its purchasing needs, manufacturers were willing to produce the new systems in hopes that other large projects will adopt them. Other Manhattan developers have expressed interest in the technologies. The Times estimated that it saves $20,000 a year per floor in lighting and air-conditioning costs.

Sometimes the smallest change can deliver a big return in carbon emission reduction and money savings. Using computer simulations, Berkeley Lab researchers demonstrated that replacing conventional roofs with "cool roofs" that use solar-reflective materials or just white paint could reduce air-conditioning energy use by 20 to 30 percent.

Building better bulbs

At the UC Santa Barbara Institute for Energy Efficiency, the lighting group has taken on the challenge of building an LED (light-emitting diode) bulb that outshines an incandescent bulb for energy efficiency and cost. The 60-watt LED light bulb the center is developing would carry a $1 price tag. UC Santa Barbara lighting researchers estimate their bulb when perfected could save $115 billion in the United States alone by 2025 and eliminate the need for 133 new power stations.

Incandescent lighting is only 4 percent efficient in converting electricity to light, compared with LEDs at 50 percent efficiency. The challenge remains to improve the LED bulb's efficiency even more and cut its cost so it can compete with incandescent bulbs.