The Analysis of Solar Potential Index in Philadelphia Hao Wang, GIS Service Group Office of Innovation & Technology
[email protected] Why We Need Solar Energy? • • • •
No green house gases Infinite free energy Going off the grid with solar Saving eco-systems and livelihoods
Resource: https://www.mrsolar.com/images/solar-panel-diagram.gif
Criticisms of Solar Energy • • • • •
Solar doesn’t work at night Solar Inefficiency – 22% (40% for fossil fuels) Storing Solar Solar panels are bulky Large upfront cost
Philadelphia—Solar City Partnership
Resource: http://www.phila.gov/green/solarMap.html
Project Objective • Analyze roof information including available area, pitch angle and solar azimuth to determine the suitability of solar panel usage. • Ultimately, the goal for this analysis is for it to serve as a good reference for the government to establish environmental protection policy and a solar energy program, and to empower the public to determine whether they should use solar energy for their own homes. Location of the dataset
Data Collection • Data includes 3D buildings and roof features of over 7,500 buildings in a 3 sq.mile area: ¾ 9th St to 25th St, East-West; ¾ W Susquehanna Ave to Vine St, North to South
• 3D base map provided by CyberCity 3D. Data is in a multipatch format with attribute: solar azimuth, pitch angle, surface area and collection date, etc.
Methodology In order to qualify for the suitability for solar panel usage, the roof must meet the following requirements (updated by Kristin Sullivan, Office of Sustainability).
Relatively Flat
Enough Space
Good Orientation
• Pitch angle < 45 Degrees • Surface area ≥ 400 Square Feet • 270 Degrees > Solar Azimuth ≥ 90 Degrees
Methodology Each required roof is given a solar potential value of 0 – 4 depending on the solar azimuth. Note: a roof with a pitch of 5 degrees or less is considered to have the same attribute and classification of a flat roof and a solar azimuth of 180 degrees.
0 – No Solar Potential 1 – Low Solar Potential
• -90 (270) Degrees ≤ Solar Azimuth < 90 Degrees • 90 Degrees ≤ Solar Azimuth < 115.7 Degrees • 244.2 Degrees ≤ Solar Azimuth < 270 Degrees
2 – Medium Solar Potential
• 115.7 Degrees ≤ Solar Azimuth < 141.4 Degrees • 218.5 Degrees ≤ Solar Azimuth < 244.2 Degrees
3 – High Solar Potential
• 141.4 Degrees ≤ Solar Azimuth < 167.1 Degrees • 192.8 Degrees ≤ Solar Azimuth < 218.5 Degrees
4 – Highest Solar Potential
• 167.1 Degrees ≤ Solar Azimuth < 192.8 Degrees
Results in Study Area
Distribution of Solar Potential Index Total Number of Roof Features & Percentage
0 – No Solar Potential
0
31616; 69.10%
1 2
1 – Low Solar Potential
4
2 – Medium Solar Potential 3 – High Solar Potential
4 – Highest Solar Potential
3
13431; 29.36%
77; 0.17%
606; 1.32% 23; 0.05%
Total Roof Area (Acre) & Percentage 0
362.09 Acre; 72.62%
118.57 Acre; 24.78%
1 2 3 4
1.66 Acre; 0.33%
15.08 Acre; 1.20 Acre; 3.02% 0.24%
Discussion • Most of the square footage of roofs have an Index 4, meaning highest solar potential. • The reason why we have a large percentage of Index 4 roofs is because Philadelphia has substantial flat roofs, where residents can easily adjust their solar panel to catch maximum solar radiation. • The distribution of roofs with each index value is expected to change when additional areas of the city are digitized and calculated for solar index.
Web Map in ArcGIS Online
Screenshots No SP
Highest SP
Low SP
High SP
Medium SP
Next Steps… • Shadow Analysis Nearby buildings and tree canopy will generate shadow affecting the solar potential of roof features.
• Economic Analysis Eventually, we wish to consider the performance and ROI of roof surfaces to determine and monetary solar potential. An example of shadow analysis
Thank you! Contact: • James Querry, Enterprise GIS Director, GIS Service Group,
[email protected] • Sarah Cordivano, GIS Specialist II, GIS Service Group,
[email protected] • Hao Wang, GIS Intern, GIS Service Group,
[email protected]