Energy Efficiency
Install / Maintain Ballast Or Control Mechanism To Minimize Lighting Use Near Windows

What Is It?

A room or office with sunlight coming through the windows may not need all its lights on at 100 percent power throughout the day. Using ballast or control mechanisms to modulate lighting near windows allows artificial lights and sunlight to be used together in the most efficient way possible. A ballast, or other control mechanism, enables light dimming that responds to actual demand. Light sensors are another effective option: they detect ambient light in the area and dim lights through the ballast as necessary.


Lighting control mechanisms save energy and can lower electric bills. Actual savings can vary depending on the amount of natural sunlight in the region, the type of windows a building has, the building’s typical occupancy schedule, and other factors such as electricity rates and light sensor settings.

Read morePDF about the benefits of installing and maintaining a ballast or control mechanism to minimize lighting use near windows.

Challenge Participants Currently Adopting This Practice

Financing Options, Incentives, And Rebates

Additional Resources

Examples of Boston Area Buildings with ballast or lighting control mechanisms to minimize lighting use near windows:

A Small Sample of Providers and Installers around Boston:


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