PV Tensegrity Forest
PV Tensegrity Forest w/ Woojae Sung
1. Why we selected Solar harvesting in Freshkills Park.
-The goal of this project is not only creating energy Generator, but also introducing Land Art into the FreshKills to trigger the functions of park as a public assembly, recreation and wild life friendly space. In terms of energy generation efficiencies, wind turbine can be operated more efficiently when the turbine is large and located high. It means the wind harvesting requires more centralized system with massive scale structure like skyscrapers. However, photovoltaic system has more flexibility in terms of size and height of panels relative to wind turbine system. It is more depending on the facing of photovoltaic surfaces to the Sun, not on the centralized mega structure. For this reason, we believe that energy generator utilizing solar resource in this open, horizontal park space has better possibilities of energy generation while creating various relationships of scales, heights, densities, programs and views with Freshkills landscapes.
2. Basic Concept
-The idea has started from the aesthetic vision which could be achieved in this park setting while producing energy with solar resource. To achieve this, the proposal juxtaposes 3 main components from the ground to the sky: Green (Freshkills), Structural Forest (Tensegrity structure) and Shimmering surface (PV panels) with energy producing technologies embedded. PV panels are always facing the Sun and being located above the ground level, but sometimes it comes down to touch the landscapes and it generates several programs & activities inside the space with various structural beauties. Inside the forest like space, visitors can mainly experience the rhythmic patterns of tensegrity structures and their roughness with various lighting condition penetrating through PV panels and perforated canopies. Simultaneously, visitors can see the movement of glossy subtle curvilinear surfaces below sky, which is harmonized with landscape below.
3. PV Panel Selection Process
– PV panel canopy transforms the park into an energy field where we harvest a significant amount of electricity out of open meadow. In addition and more importantly, it also provides an opportunity for us to interact with the park by having multiple event spaces to attract people to the site. That being said, what we want to achieve was straightforward: cover the park with PV panels as efficiently as possible to get maximized level of electricity output yet to provide enough event spaces utilizing the park’s context as well as PV panel canopy systems. For this, we cover the entire park with PV panels by draping panels onto the topography of the site. Considering climate data of the site, especially sun’s path as well as on site conditions such as road, context and newly inserted programs. At the end of this process we got the most efficiently sun-facing PV canopy that also serves as beautiful spaces for human activities.
4. Project area
– The proposed 10’ X 10’ triangulated PV panel network is overarching from North to East Park. The total boundary area is around 70 acres and the total PV panel surface area is 54 acres. This may produce 117,835 KW/day, which is equivalent to the 2,370 houses’ electricity uses per day.
5. Tensegrity structure (3-prism system)
-As the design brief recommended, one of the main concerns when deploying PV panels on the landscape is how to keep the existing park built-up & caps intact. As a possible solution, Tensegrity structure with tension cable networks & compression rods is introduced to support the PV panels above. By deploying solar panels with tensegrity structure, we can establish more structural flexibility which can make the whole PV fields more easily responding to the settling landfill of the Freshkills. The other advantage of tensegrity is that the system is structurally self-supporting, and able to be installed and moved very easily, because the structure is not physically attached to the ground without any possible penetrations. This flexible structural network can be laterally braced each other to obtain more structural rigidity especially some programic decks or installations hung on the structures.
6. Program insertion
-The Bamboo forest like space under PV canopies can be used as occupiable spaces with various public activities in it. The bottom triangular grid of tensegrity structure generates hexagonal voids between them, and the size & the density of those occupiable spaces can be controlled by the parametrical relationships to the height of canopies as you can see from the enlarged plan. The possible programs will be Viewing Deck, Exhibition/sunbath deck, Promenade, Stage, Mezzanine Deck, Forest and Wild life watching point, etc. Of course, the required electricity can be supplied from the above PV panels to support these public activities below.
7. Energy Production & Use
-As mentioned above, the total surface area of PV panels are around 54 acres (2,356,712sft). This can produce 117,835 kW per day (=0.01kW/sft*hr x 2,356,712 sft x 5hr). This number is based on the assumption that 1sft of PV panel can generate 0.01 kW per hour, and 5 hour is available duration per day for solar harvesting. This amount of electricity can support 2,370 neighboring residences, and also support the public activities and basic required necessity for the Freshkills Park.