Next Tuesday, we’ll be digging into the design process and vision for the Lowline Lab, an underground pilot park now open to the public every weekend. Star Davis, daylighting and lighting designer at Arup, gave us a look at the solar technologies needed to make the project viable—and to serve as a potential model for transforming other underutilized spaces.
Photo: Liz Ligon
Efficient But Dependent
“The solar collection system we have currently installed in the lab has never been used in the United States, and never for an application of this kind,” says Davis, and distributing the sytem’s concentrated sunlight is one of the greatest challenges the Lowline Team is working though. While each lens, mirror, or surface that interacts with the light is optical quality and specifically selected and engineered for its light reflection or redirection properties, the actual efficiency of the system is dependent on the length that the light must travel and the number of times they need to reflect and spread it. That said, the technology delivers a greater quantity of light that what the Lowline Team thought was possible, and they’re very excited to see the other possibilities that the technology has to offer.
While the system is the most efficient on the market, it relies almost entirely on direct sunlight to work, which means it must be supplemented with electric lighting when weather conditions are not ideal.
Image: Raad Studio, LLC
Sunlight is an incredibly powerful source of radiant energy, and ultraviolet (UV) rays can damage and degrade materials, including our skin, while infrared rays (IR) pack a lot of heat. The Lowline Lab’s technology intensely concentrates the sunlight, which can be quite dangerous, to which anyone who has played with a magnifying glass in the sun can attest. The impact magnifies at larger scales as well, if you recall the car-melting-solar-death-ray building in London that made headlines a few years back.
Recognizing these risks, the lab’s equipment employs a variety of safety measures, the first of which is spectrally selective coatings that reduces the quantity UV and IR light that enters the collection system. This prevents the more harmful rays from reaching the interior environment. The catch, of course, is that UV and IR light is the part of the spectrum that plants require to thrive—the UV stimulates growth while the longer IR wavelength light stimulates flowering (depending on the species). “We were concerned about how the plants would react to our reducing these wavelengths,” says Davis, “but nine months into the experiment, they are still flourishing!”
Serving Community, Transforming Spaces
“The lab has really functioned to bring the community in, creating a place of assembly for activities and socialization, while also allowing for discovery and education,” says Davis. “We have on display the full cycle of plant and food growth, as well as hands-on demonstrations in physics. We’re using the lab to invite feedback and direction from the community on the future Lowline park, and we’re actively exploring what type of space or activities would be most desired and beneficial to our neighbors.”
Beyond growing urban plants and serving the local community, there are existing buildings and infrastructure all over the world where the majority of the space is completely cut off from sunlight. Some of these spaces sit vacant, while others just suffer from poor quality of light and environment. “By pushing the boundaries of advances in technology,” says Davis, “we have an opportunity to transform and repurpose a vast of stockpile of existing infrastructure.”