3.10.1.4 Default Parameters for Modeling PRPpre when no On-Site Renewable Systems are Specified in the Proposed Design

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G3.2 New Construction/Major Alterations

This section only applies to projects following Standard 90.1-2022 Section G3.2. This is because alterations are exempt from the on-site renewable energy requirements in Standard 90.1-2022 Section 10.5.1.

The PCIt (performance cost index target) equation in Standard 90.1-2022 Section 4.2.1.1 includes a term to account for proposed building performance excluding any renewable energy systems in the proposed design and including an on-site renewable energy system that meets but does not exceed the requirements of Section 10.5.1.1 modeled following the requirements for a budget building design in Table 12.5.1, row 15 (PBPpre). Recall, for a project following 90.1 2022 Appendix G to be considered minimally compliant with 90.1 2022 the PCI performance cost index (PCI) needs to be less than or equal to the PCIt. The descriptors below are for modeling PBPpre when no on-site generation systems are specified in the proposed design.

Shading Objects
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	A unique identifier that can be used to reference shading objects.
Units	Text, Unique
Input Restrictions	None.Unshaded.
Baseline Building	None (PV not modeled for the baseline building)

Size
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	The size describes the rated capacity of the PV system.
Units	Power, kW or Btuh.
Input Restrictions	Established per Standard 90.1-2022 Section 10.5.1.1 which requires that the building site shall have equipment for on-site renewable energy with a rated capacity of not less than 0.50 W/ft² or 1.7 Btu/ft² multiplied by the sum of the gross conditioned floor area for all floors up to the three largest floors. The following exceptions apply: Any building located where an unshaded flat plate collector oriented toward the equator and tilted at an angle from horizontal equal to the latitude receives an annual daily average incident solar radiation less than 1.1 kBtu/ft2·day. Any building where more than 80% of the roof area is covered by any combination of equipment other than for on-site renewable energy systems, planters, vegetated space, skylights, or occupied roof deck. Any building where more than 50% of roof area is shaded from direct-beam sunlight by natural objects or by structures that are not part of the building for more than 2,500 annual hours between 8:00 a.m. and 4:00 p.m. New construction or additions in which the sum of the gross conditioned floor area of the three largest floors of the new construction or addition is less than 10,000 ft2. Alterations.
Baseline Building	None (PV not modeled for the baseline building)

Module Type and Efficiency
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	The type and efficiency of the PV system.
Units	Text and Ratio.
Input Restrictions	Crystalline silicon panel with a glass cover, 19.1% nominal efficiency; performance shall be based on a reference temperature of 77°F and irradiance of 317 Btu/ft²·h.
Baseline Building	None (PV not modeled for the baseline building)

Module Temperature Coefficient
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	Temperature coefficient measures the percentage of power output that is lost by a specific solar panel as the temperature rises.
Units	%/°F.
Input Restrictions	–0.19%/°F
Baseline Building	None (PV not modeled for the baseline building)

Nominal Operating Cell Temperature (NOCT)
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	The normal operating cell temperature, typically between 45°C and 55°C
Units	Degrees Celsius (°F)
Input Restrictions	103°F
Baseline Building	None (PV not modeled for the baseline building)

Total System Losses
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	System losses are the losses in power output from the conversion from direct current to alternating current.
Units	Ratio, power lost/total power
Input Restrictions	11.3%
Baseline Building	None (PV not modeled for the baseline building)

Tilt
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	The tilt angle is the angle from horizontal of the photovoltaic modules in the array. The tilt angle is the angle from horizontal of the array where 0° = horizontal, and 90° = vertical.
Units	Degrees (°)
Input Restrictions	0-degrees (mounted horizontally)
Baseline Building	None (PV not modeled for the baseline building)

Azimuth
Applicability	PV systems when no on-site renewable systems are specified in the proposed design.
Definition	The azimuth angle is the angle clockwise from true north describing the direction that the array faces. An azimuth angle of 180° is for a south-facing array, and an azimuth angle of 0° is for a north-facing array.
Units	Degrees (°)
Input Restrictions	180-degrees.
Baseline Building	None (PV not modeled for the baseline building)