LED Art at City Scale

A San Francisco visionary and a world-renowned artist whose medium is light and software have teamed up to produce the world's largest LED light sculpture.

Take four shallow isosceles triangles strung out in a line, but not connected. Make each one 2,100 feet long (that's 640 m) and 240 feet high (73 m) at the peak. That's your canvas. Play video on it. The pixels are separated by 1 foot (0.3 m) vertically and 30 feet (9.1 m) horizontally.

Each pixel is a Philips Color Kinetics eW Flex SLX LED (4200K CCT). Each has its own IP address. There are 25,000 of them. They are fed by 528 Philips PDS-60ca 24V power and data supplies, one per bridge cable. (Note: Philips sponsors this site.)

The Bay Lights went live early last month on the north side of the western span of the Bay Bridge, 1.8 miles (2.9 km) long. The light display runs from dusk till 2:00 a.m. every night, and will for the next two years.

The project, from inception to deinstallation (if indeed that happens) is budgeted at $8 million. It's all being raised from private funds; $6 million is in hand so far. (You can "sponsor" an individual lamp for $50.) The energy budget for all those LEDs is about $11,000 per year: the lights use something north of 150 kWh for seven hours each day, at a cost of around $30 a night. (Bay Lights is donating that amount to a local solar power company as an offset.)

The artist, Leo Villareal, claims that the light patterns will never repeat. His algorithms are based on the idea of emergent behavior. Villareal sets some initial conditions and lets the city-scale visual effects emerge, unpredicted and unpredictable. He says he took his inspiration for the light patterns from watching the bridge from many vantage points, against its backdrop of waves, wind, clouds, and birds.

Ars Technica quotes Ray Cooper, a senior project manager at Transdyn, the company tasked with the communications aspects of the installation, on the network arrangements:

[Villareal] has his light program running on some computers within a network equipment rack. That's connected to an Ethernet switch which is in turn connected to several media converters. We have fiber [running] across the bridge, and we have 24 router cabinets and are all home run back to the cabinet. From each router box we go to the switch cabinets that are tied to the light boxes themselves [that would be the Philips PDS-60ca] that run the LEDs. The network is in place to operate the individual light strings. [Villareal's] computer that's running his program is sending out commands to each of these IP addresses across the network.

Mashable identifies the computers running the light-control program as Mac Minis booted to Windows 7. Villareal controls things from his own laptop, from somewhere near the bridge. The video above shows a few seconds of footage of his control program (starting at about 1:35). It sounds like he ssh'es into one of the Mac Minis to get the process kicked off each evening.

Fifty million people will see this public art in the next two years. San Francisco's mayor estimates that it will bring in $97 million in additional revenue to the city in that time. The Bay Lights project can't help but elevate the profile of LED lighting.

— Keith Dawson , Editor-in-Chief, All LED Lighting