For 48-733: Environmental Performance Simulations​​​​​​​ and 48-722: Building Performance Modelling
There are 2 parts to this project. Part-1: Using ArchSIM for Grasshopper, the total annual electricity (DC -type) generation is calculated for an existing house. Part-2: Using Design Builder, a Solar Photovoltaic System is designed for an existing office building.
Part-1:
STEP-1:
Using Ladybug for Grasshopper, it's built-in function of “Tilt and Orientation Factor (TOF)” is used to find the ‘Optimal Tilt’ and ‘Optimal Azimuth’.

Solar radiation graph as a function of panel tilt/orientation ​​​​​​​

After running the simulation, the Optimal Tilt angle and Optimal Azimuth is discovered to be 36° and 180° respectively. Only if we set our proposed solar panels to these angles, a TOF of 100 can be achieved. Currently, the analyzed model has a TOF of 87.8. TOF is the ratio of the solar radiation gain at the actual tilt and orientation (before optimization) to the solar radiation gain at the optimal tilt and orientation (after optimization). So, the higher the TOF the better the panel position.
STEP-2:
Electrical performance specifications of an actual mono-crystalline(c-Si) solar PV panel (“Sun Module SW 185MONO”) are used to calculate total peak power of the entire PV system.

Solar PV Panel dimensions and its specifications

The total peak power (at STC) of the entire solar PV system is 3.7kWp.  The peak power of 1 solar PV module is 185Wp. Therefore, the total number of solar panels required to meet the requirement is 20(3700/185) .
Using the optimal positioning information, a rooftop solar PV array with 1.2m offset distance was developed parametrically on Grasshopper from the perimeter of the roof surfaces and 1.2m distance between each successive solar PV arrays (on the horizontal planes).

Different layout options for the solar PV array

Layout that does not compromise the TOF of 100 was selected with a tilt of 36°, Azimuth of 180° and 20 panels in total

Isometric view of the final layout chosen

STEP-3:
By using ArchSim to develop a solar PV electric model, total annual electricity (DC -type) generation is calculated. All PV panels from Step-2 are inputted for both ‘panels’ and ‘shading’. The Solar cell Efficiency is set to 16.32% and effective panel area to 86.26%. Once the ‘monthly’ and ‘annual’ electricity generation is calculated, it is converted into kWh by using the conversion factor of ‘3600000’.
​​​​​​​
- Total Floor area of Esherick house = 192.7 m2
- Annual electricity consumption of Esherick house (58.84 kWh/m2-yr) X (192.7 m2) = 11,338.4 kWh (Cooling + Equipment + Lighting)
- Annual Solar energy generated from the solar panels = 4658.5 kWh
- Percentage of solar generated electricity that satisfies the annual electric energy consumption = 41%​​​​​​​
Part-2:
STEP-1:
Two solar PV electrical performance models were built within Design Builder for a unit solar PV module (SunModuleSW185Mono) - one 'simple' performance model and one 'equivalent one-diode' performance model.
STEP-2:
A geometric model of an array of rooftop solar PV panels is made based on the following factors - 1.20m of offset
distance from the perimeter/edge of the roof and between 2 arrays, 28° tilt angle of the panel and total peak power (at STC) of the entire rooftop solar PV system to be 7.4 kWP. A geometric model of array of PV panels as shading device is also made with with a tilt angle of 0°.

View of the final layout on Design Builder

STEP-3:
Equivalent one-diode PV performance model is assigned to the rooftop PV and simple PV performance model is assigned to the shading device. Two different electric load centers are assigned for each PV system with DC-to-AC inverter model with constant (24x7) conversion efficiency of 0.96. Annual simulations are run for Pittsburgh.
- Total PV area = Rooftop PV - 45 sq.m, Shading device PV - 33.75 sq.m
- Total number PV modules = 40 solar PV modules and 30 shading device type PV modules
- Total annual solar energy generation = 15423.965 KWh (Site Energy Basis) | 48847.697 KWh (Source Energy Basis)
- Percentage of electric loads satisfied = 5.00%