Walking past rows of greenhouses aglow with overhead lights on a dusky day, Nick Van Eck and Andy Leed turn into a room full of enormous metal boxes. These are growth chambers designed to optimize plant research -- from better strains of native grasses for biofuels to enriched rice to feed a hungry world. Each chamber closely regulates light and temperature to create ideal conditions for a wide range of studies.

Yet as ideal for growth as these chambers are, they're energy hogs, mostly because of their lights. Van Eck and Leed head a Cornell University Agricultural Experiment Station (CUAES) team that, working with engineers from the university's Office of Energy and Sustainability, is retrofitting the most energy-inefficient chambers, replacing old-style fluorescent lights with more efficient longer-lived bulbs. Van Eck points to one of the 22 chambers built in the early 1960s and currently under renovation as part of a $600,000 project to be completed this fall, financed in part by the New York State Research and Development Authority.

"That chamber is using 54 percent less electricity," said Van Eck. "Yet the new tubes put out four times as much light per watt." Not all 130 CUAES growth chambers date to 1964, but none are efficient by today's standards.

Outside each chamber stands a noisy control box the size of a double-wide refrigerator. Leed steps to a neighboring chamber and tugs open a control box door. "In 1964 these were state of the art," he said. The box is full of transformers, vacuum tubes and time clocks. But the new digital control box on the retrofitted chamber is the size of a desktop computer and just as quiet.

This control box also tracks temperature to help cut growth-chamber heating and cooling energy by nearly 75 percent. Each control box will tie to a centralized digital control, a main-brain of sorts that handles not just each complex's growth chambers but its greenhouses as well. "We aim for the highest standards of sustainability in everything we do," said Mike Hoffmann, the experiment station's director.

So far 358 of the inefficient 1,000-watt canopy greenhouse lights have been replaced in the 26 campus-area greenhouses that CUAES manages with long-life, 600-watt bulbs that provide more uniform light while saving energy. The old lights ran constantly, rain or shine. But the digital controls adjust light levels, heating and ventilation to reflect conditions outside.

"Now we won't be heating and cooling the greenhouses at the same time," Leed said.

Another benefit: "With the old controls," Van Eck said, "if an alarm went off and no one was around to hear it, who would know? The new system calls our cell phones."

The growth chambers' return-on-investment alone is three years. Altogether, greenhouse and growth chamber yearly carbon dioxide emissions should drop at least 667 metric tons. Meanwhile, with the new systems, maintenance costs will drop dramatically, saving up to $458,000 a year, Leed said, yet growing conditions will be better than ever.

"We are happy to turn the great ideas of our staff and researchers into very cost-effective conservation projects," says Lanny Joyce, facilities director at Cornell, who orchestrates the retrofits. "But most important is the connection to making our research areas much more sustainable."

Other partners in this work include Contract College Facilities and the Cornell Facilities Air Conditioning and Refrigeration Shop.

Mary Woodsen is a science writer with the Cornell University Agricultural Experiment Station.