Image analysis and estimation of rooftop solar exposure via solar ray mapping
An unmanned aerial vehicle (UAV) solar irradiation assessment system may automate several design parameters of solar panel design, cost and payoff estimations, and installation. The system models a structure and surrounding obstacles in a three-dimensional space. The system maps ray paths between each of a plurality of locations on a roof of a structure and modeled locations of the sun at various time intervals during a selected time period to determine the solar irradiance at various locations. Obstacles modeled in three-dimensional space that block the ray-paths during some or all of the various time intervals result in decreased solar irradiance values for the affected locations on the roof. A visual model of the roof may be shown with a heatmap of irradiance values and/or a graphical placement of solar panels.
1. A system for determining solar exposure on a roof of a structure, comprising:
an unmanned aerial vehicle (UAV) system to navigate a flight pattern relative to a structure;
a camera on the UAV to capture images of the structure and a surrounding obstacle;
a modeling system to spatially model the surface of the roof and the surrounding obstacle; and
an irradiance exposure subsystem to calculate a total solar irradiance on the roof via evaluation of ray paths between each of a plurality of locations on the roof and modeled locations of the sun at various time intervals during a time period.
2. The system of claim 1 , wherein the irradiance exposure subsystem calculates the total solar irradiance on the roof by:
conceptually dividing a modeled surface of a roof into a plurality of polygons;
modeling ray paths between each polygon and modeled locations of the sun relative to the surface of the roof at each of a plurality of different times and days during the time period;
calculating an angle of each modeled ray path relative to the normal of each respective polygon at each of the plurality of different times and days;
calculating a total solar irradiance on each polygon between a first time and a second time based on the calculated angles of the ray paths between the first and second times; and
calculating a total solar irradiance on the surface of the roof between the first and second times based on the summed total solar irradiance on the polygons on the surface.
3. The system of claim 2 , wherein the polygons comprise one or more of triangles, rectangles, rhombi, and hexagons.
4. The system of claim 2 , wherein each polygon has an edge length between 0.1 and 0.5 meters.
5. The system of claim 1 , further comprising a solar panel placement subsystem to calculate and display a solar panel size recommendation based on the calculated total solar irradiance on the surface of the roof.
6. The system of claim 5 , wherein the solar panel placement subsystem is further configured to calculate and display a recommended angle for installation of the solar panels relative to the surface of the roof.
7. The system of claim 1 , wherein the irradiance exposure subsystem calculates the total solar irradiance on the roof during a time period that spans multiple years.
8. The system of claim 1 , wherein the time period comprises one of: a one-month period, a three-month period, a twelve-month period, and a multi-year period.
9. A system for determining solar exposure on a roof of a structure, comprising:
an imaging subsystem to utilize images captured by a camera on an unmanned aerial vehicle (UAV) during a flight pattern executed relative to a structure;
a ray-path modeling subsystem to model ray paths between modeled locations of the sun relative to the structure and each of a plurality of locations on a surface of the structure; and
an irradiance calculation subsystem to calculate a total solar irradiance on the surface of the structure during a time period in which the sun is modeled as moving from a first location relative to the structure to a second location relative to the structure.
10. The system of claim 9 , wherein the irradiance calculation subsystem calculates the total solar irradiance on the surface of the structure by
conceptually dividing a modeled surface of a roof into a plurality of polygons;
modeling ray paths between each polygon and modeled locations of the sun relative to the surface of the roof at each of a plurality of different times and days during the time period;
calculating an angle of each modeled ray path relative to the normal of each respective polygon at each of the plurality of different times and days;
calculating a total solar irradiance on each polygon between a first time and a second time based on the calculated angles of the ray paths between the first and second times; and
calculating a total solar irradiance on the surface of the roof between the first and second times based on the summed total solar irradiance on the polygons on the surface.
11. The system of claim 10 , wherein the polygons comprise one or more of triangles, rectangles, rhombi, and hexagons.
12. The system of claim 11 , wherein each polygon has an edge length between 0.1 and 0.5 meters.
13. A non-transitory computer-readable medium with instructions stored thereon that, when executed by a processor, cause a computing device to implement operations to:
conceptually divide a modeled surface of a roof into a plurality of polygons;
model ray paths between each polygon and modeled locations of the sun relative to the surface of the roof at each of a plurality of different times and days;
calculate an angle of each modeled ray path relative to the normal of each respective polygon at each of the plurality of different times and days;
calculate a total solar irradiance on each polygon between a first time and a second time based on the calculated angles of the ray paths between the first and second times; and
calculate a total solar irradiance on the surface of the roof between the first and second times based on the summed total solar irradiance on the polygons on the surface.
14. The non-transitory computer-readable medium of claim 13 , wherein each of the polygons comprise one of a triangle, a rectangle, a rhombus, and a hexagon.
15. The non-transitory computer-readable medium of claim 13 , wherein each polygon has an edge length between 0.1 and 0.5 meters.
16. The non-transitory computer-readable medium of claim 13 , wherein the operations further comprise displaying, via a graphical user interface, a solar panel size recommendation based on the calculated total solar irradiance on the surface of the roof.
17. The non-transitory computer-readable medium of claim 16 , wherein the operations further comprise calculating and displaying a recommended angle for installation of the solar panels relative to the surface of the roof.
18. The non-transitory computer-readable medium of claim 13 , wherein the difference between the first and second times spans multiple years.
19. The non-transitory computer-readable medium of claim 13 , wherein the difference between the first and second times comprises one of: a one-month period, a three-month period, a twelve-month period, and a multi-year period.