Offset = 75% min <> 120% max
Minimum System Size DC = 5.98kW
Maximum System Size DC = 19.32kW
Production Factor Min = .80
Massachusetts Equipment
Panels: Aptos 460w
Optimizers: Tigo TS4-A-O (700W)
Battery: Renon Xcellent Plus 16kWh
Inverters: Solark 12kW or 15kW
Inverter sizing must match battery count and system size:
Sol-Ark 12K-2P-N → 1 battery system between 5.98-12.88kW-DC
Sol-Ark 15K-2P-N → 2 battery systems between 9.66-19.32kW-DC
A critical load panel is required for every system
Settings in Aurora
Prior to design work, please align your simulation settings with the following:
General Settings
Simulation: Auto
Shading Engine: On
Use LiDAR Shading: On
If tree removal is indicated in the project submission, please turn off LiDAR, model in trees according to LiDAR and Google Earth, excluding the trees indicated for removal.
Use Horizon shading: On
Aurora
Irradiance Model: Perez
Inverter Clipping: On
Weather Dataset: PSM3, NREL-PSM, TMY3 or TMY2
System Losses (See Total Percentage by state in System Loss Chart, below is just a suggestion)
Parameter | Value |
Nameplate rating | 1.00% |
Mismatch | 1.50% |
Connections | 0.50% |
Light-Induced Degradation | 1.50% |
Wiring | 2.00% |
Soiling | 2.00% |
Availability | 1.00% |
Shading | Varies by site |
Age | 0.00% |
Snow | 4.00% |
Other | 0.0% |
Daylight's Aurora Design Requirements and Standards
1. Customer Usage & System Sizing
Start every design with customer annual usage (kWh). Input the monthly consumption values from the utility bill into the Energy Details section in Aurora.
Aurora's system will estimate any months that are missing
2. Roof Selection Priority (Panel Placement Order)
Panels should be placed in the following order to maximize production:
South-facing roof or most south-facing plane
South-West and South-East
West and East
North-East and North-West (last resort)
No true North-facing roofs should be used unless absolutely necessary to achieve the minimum system size (5.98kW) or production goals.
Shading from nearby obstructions, such as trees or buildings, should also be considered in panel placement. Favor roofs with higher TSRF when deciding between azimuths.
Prohibited Roof Types: Flat, Rubber, Slate, Terracotta
3. Azimuth, Stringing & MPPT Standards
Avoid mixing azimuths/roof planes within a single string. Assign one MPPT per azimuth whenever possible.
Do not mix North- and South-facing arrays within the same MPPT.
4. MPPT Utilization
Utilize all available MPPTs when array size allows: 2 MPPTs per 12kW Solark, 3 MPPTs per 15kW Solark.
Balance the number of panels per MPPT as evenly as possible.
Do not overload one MPPT while leaving others unused.
5. Minimum String & Array Requirements
Minimum of 5 panels per string per azimuth.
If a roof plane has fewer than 5 panels:
Add panels where feasible, or
Redesign stringing.
6. Production Factor, Solar Access Overall & TSRF
Design and QA/QC threshold:
Production factor must be greater than 0.80.
Solar access indicates the percentage of sunlight hitting the roof, while TSRF factors in shade, tilt, and orientation.
Solar production factors (or capacity factors) are calculated by dividing the actual annual energy production (kWh) divided by system size (kW)*1000