Central park Solar Folies
Solar panel optimization for Great Hill Central Park
Bingyu Xia, Gejin Zhu, Risa Mimura, Yining Lai, Zihan Sun| Generative Design| Fall 2021| GSAPP
Introduction
Central Park as one of the largest public spaces in New York city is visited by thousands of visitors everyday. In a city surrounded by skyscrapers, it’s initial intention was to provide New Yorkers a place they can go to experience the countryside and a place to escape from the urban environment. Abundant of green and sunlight, it is the place with the most daylight and green throughout the year within Manhattan.
Design Intention
“Central Park Solar Folies” is a design proposal to suggest a possibility to make better use of the abundant sunlight that shines on Central Park. More specifically, we are introducing a multi-layer system of single column supported solar panels in the meadows located in Central Park. Great Hill, one of the highest points located at the northwest corner of the park, is selected as the site for this study.
The goal for this project is not only to increase the solar energy production and reduce greenhouse gas emission in New York City, but also to raise awareness of the scarcity of sunlight in the city of New York. Renewable energy is becoming a central topic for energy production during the era of climate change. It is crucial for people to understand the production of solar energy in relation to the power usage of the entire city.
Methodology
The objective for our project is to maximize solar energy production through solar panels with a series of solar angles without disrupting the existing space use and circulation. Great Hill is closed during winter season but is a very active area of Central Park during the other seasons, the solar panel installation would not be disturbing the original purposes of the meadow.
Sunlight Analysis
Starting with a site analysis of Great Hill, we identified the potential interference for sunlight angles and circulation routes within the area. In the case of this particular area, since no surrounding building would be casting shadows on the site, plantation within the park is the major criteria of our sunlight analysis. Ladybug Tools was used to acquire the sun path and direct sunlight hour throughout the year for Central Park.
Circulation Routes
Great Hill turns into a popular spot for picnic and leisure activities during warm seasons, therefore circulation is another critical factor that defines our proposal. Since the top of the hill is connected to a total of 8 routes, it provided us some flexibility to recalculate the circulation after placing the solar panels.
Manual Inputs
Site Area- The meadow on Great Hill takes an oval outline, the area size is approximately 200ft by 300ft, surrounded by black locust, American elm and tulip trees( height ranges from 40–100ft). Because it is situated on the top of the hill, the landscape is assumed to be a planar surface.
Surrounding -The location and diameters of trees are determined from aerial photographs of Central Park during the summer, the height of the trees are manually inputted by an average measurement of 65 ft(20m). The shape of the trees are assumed to be a regular ellipsoid.
Solar Panel Size- In order to accommodate the oval outline and irregular shading condition caused by trees, three sizes of circular panels are installed to ensure the solar panels can be evenly placed throughout the areas with the greatest direct sunlight and the longest sunlight hour. The three panel sizes are 33 ft(10m), 23ft(7m) and (13ft)4m in diameter, each of the panel is supported with a steel column of 16 ft (5m)height.
Parameterization of Solar Panel Placement
Once the site model with surroundings is constructed in rhino, Ladybug Tools was used to visualize the sunlight hour and location data on the site in relation to shadows casted by trees. The sunlight amount is divided into three ranges in response to the three sizes of panel. We believe direct sunlight hour can be the primary criteria that determines the sunlight exposure amount each panel get, therefore the three ranges are divided into: 1) 33ft diameter panel will be placed in areas with direct sunlight for over 16 hours , 2) 23ft diameter panel will be placed in areas areas with direct sunlight for 12 to 16 hours, 3) 13ft diameter panel will be placed in areas with direct sunlight for 8 to 12 hours. A python script was written for this process in order to extract each location as output of each range from the total input points. The output points is then transformed into area for panel placement.
This would become the temporary position of each panel for optimization. Once the panels are placed, we run the sunlight analysis again to calculate the total sunlight amount each panel would get on its temporary location. The result would help us to conduct the optimization of the panel placement according to the maximum total sunlight amount all of the panels can achieve.
Optimization
In order to achieve the maximum total sunlight amount for the panels without interrupting the surrounding, we applied several restraints to the process. Although the panels are a multi-layer system, it would be best not to have any potential overlapping between each of the panels to avoid casting shadows while arranging them in a way that would not leave any empty spaces for potential light to be lost. Another constraint that was mentioned earlier was the placement of trees, it would be less efficient to have any panels within the shading area of trees. Combining both restraints, a python script to prevent “collision” but ensure “cluster” was written for Discover to generate designs for the best performance. The angle of each placement is randomized for each design in all generations to assure the area facing the sun would be calculated as well. Lastly, the readjusted circulation line is mapped according to the center point of each panel.
Result
We believe that there is an opportunity for this proposal to be applied not only in Great Hill but other green spaces and lakes in Central Park as well. With the installation of translucent solar panels, there would still be sufficient light passing through the panel for people to enjoy. The panels can also serve as shelter when the weather is not ideal, foldable joints can be attached to allow visitors to be able to manually control the panel as well. The installation could become an interactive project that not only produces energy but also an educational device for renewable energy.
