PV Rated Capacity
Applicability: All buildings that have onsite photovoltaics.
Definition: The rated DC capacity of the system in kilowatts.
Units: kW.
Input Restrictions: Non-negative value.
Standard Design: Requirement in 2022 Title 24 Part 6, Table 140.10(a), where required PV capacity is specified for each space function. The mapping of space function to PV capacity building type is documented in Appendix C.
Standard Design: Existing Buildings: Same as the proposed.
PV MODULE TYPE
Applicability: All buildings that have onsite photovoltaics.
Definition: The type of photovoltaic module that makes up the system.
Standard is a typical poly- or mono-crystalline silicon module, with efficiencies of 14-17 percent.
Premium is appropriate for modeling high efficiency (approximately 18-20 percent) monocrystalline silicon modules that have anti-reflective coatings and lower temperature coefficients.
Units: List Standard or Premium.
Standard Design: Standard module type.
Standard Design: Existing Buildings: Same as the proposed.
Annual Solar Access
Applicability: All buildings that have onsite photovoltaics.
Definition: The annual solar insolation (accounting for shading obstructions) by the total annual solar insolation if the same areas were unshaded by those obstructions.
Units: Percent.
Input Restrictions: 0-100 percent.
Standard Design: 98 percent.
Standard Design: Existing Buildings: Same as the proposed.
MODULE LEVEL POWER ELECTRONICS
Applicability: All buildings that have onsite photovoltaics.
Definition: The type of power electronics present in each photovoltaic module.
Units: List none, Microinverters or DC Power Optimizers.
Standard Design: none.
Standard Design: Existing Buildings: Same as the proposed.
PV TRACKING (ARRAY TYPE)
Applicability: All buildings that have onsite photovoltaics.
Definition: Whether or not PV systems are fixed or use one-axis or two-axis tracking mechanisms to improve electricity generation.
Units: None.
Input Restrictions: List: None, 1-axis, 2-axis.
Standard Design: None.
Standard Design: Existing Buildings: Same as the proposed.
CALIFORNIA FLEXIBLE INSTALLATION (CFI)
Applicability: All buildings that have onsite photovoltaics.
Definition: Whether or not PV system installation adheres to CFI limits, in which case azimuth and tilt specification is not required.
CFI1 allows the PV installation at any orientation with an azimuth from 150 to 270 degrees on a roof with a pitch from 0:12 to 7:12.
CFI2 allows the PV installation at any orientation with an azimuth from 105 to 300 degrees on a roof with a pitch from 0:12 to 7:12.
Units: None.
Input Restrictions: List: n/a, CFI1, CFI2.
Standard Design: CFI1.
Standard Design: Existing Buildings: Same as the proposed.
PV AZIMUTH
Applicability: All buildings that have onsite photovoltaics and no CFI1 or CFI2 selection.
Definition: The azimuth in degrees from true North (180F for South, for instance). Not applicable for building-integrated panels or panels installed with no tilt.
Units: Degrees.
Input Restrictions: 0 to 360 degrees.
Standard Design: 170 degrees (face South).
Standard Design: Existing Buildings: Same as the proposed.
PV TILT
Applicability: All buildings that have onsite photovoltaics and no CFI1 or CFI2 selection.
Definition: The tilt of the PV panels from horizontal, in degrees.
Units: Degrees.
Input Restrictions: 0 to 90 degrees.
Standard Design: 22.61 degrees.
Standard Design: Existing Buildings: Same as the proposed.
PV INVERTER EFFICIENCY
Applicability: All buildings that have onsite photovoltaics and detailed inputs is selected.
Definition: The rated efficiency of the inverter in converting DC to AC power.
Units: Percent.
Input Restrictions: 0-100 percent.
Standard Design: 96 percent.
Standard Design: Existing Buildings: Same as the proposed.
Battery Energy Storage Capacity
Applicability: All buildings that have onsite battery storage.
Definition: The storage capacity of all onsite battery storage, in kWh.
Units: kWh.
Input Restrictions: Positive number.
Standard Design: The battery storage matches requirements in 2022 Title 24, Part 6 Section 140.10(b), where required storage capacity is specified for individual space functions. The mapping of space function to battery storage capacity by building type is documented in Appendix C.
Standard Design: Existing Buildings: Same as the proposed.
Battery Charging/Discharging Rate or Roundtrip Efficiencies
Applicability: All buildings that have onsite battery storage.
Definition: The efficiency of charging and discharging electricity to and from the battery.
Units: Fraction.
Input Restrictions: Positive number.
Standard Design: The design charge and discharge efficiencies are 95%.
Standard Design: Existing Buildings: Same as the proposed.
Battery Charging/Discharging Rates (Power) Capacity
Applicability: All buildings that have onsite battery storage.
Definition: This equals the building load (power) that can be offset when the battery is discharging. Typical batteries have rated power storage for 2 to 4 hours of discharge capacity.
Units: kW.
Input Restrictions: Positive number.
Standard Design: The battery storage charge and discharge rates (power) match requirements in 2022 Title 24, Part 6 Section 140.10(b), where required battery capacity is determined by individual space function.
Standard Design: Existing Buildings: Same as the proposed.
Battery Discharge Control
Applicability: All buildings that have onsite battery storage.
Definition: Batteries for energy storage can be controlled by one or more strategies.
Units: None.
Input Restrictions: List:
Basic (Default Control). A simple control strategy that provides a modest credit. The compliance software assumes that the batteries are charged anytime PV generation (generation) is greater than the building load (load); conversely, the batteries are discharged when load exceeds generation. This control strategy does not allow the batteries to discharge into the grid.
Time of Use. To qualify for the TOU control, the battery storage system shall be installed in the default operation mode to allow charging from an on-site PV system or from the utility grid if a stand-alone battery storage system. The battery storage system shall begin discharging during the highest-priced TOU hours of the day, which varies by time of the year and the local utility. At a minimum, the system shall be capable of programming three seasonal TOU schedules, such as spring, summer, and winter. This option allows discharging directly into the grid.
Advanced Demand Flexibility Control. To qualify for the advanced demand flexibility control, the battery storage system shall be programmed by default as basic control or TOU control, as described above. The battery storage control shall meet the demand-responsive control requirements specified in Section 110.12(a). The battery storage system shall have the capability to change the charging and discharging periods in response to signals from the local utility or a third-party aggregator. Upon receiving a demand response signal from a grid operator, this option allows discharging directly into the grid.
Standard Design: Time of Use (TOU) battery control.
Standard Design: Existing Buildings: Same as the proposed.
TOU Start/End Months
Applicability: All buildings that have onsite battery storage with Time of Use control.
Definition: The start and end months where the Time of Use control scheme is active.
Units: none.
Input Restrictions: Positive number 1-12.
Standard Design: TOU battery control operates all year, months 1-12.
Standard Design: Existing Buildings: Same as the proposed.
Simulate Standalone Battery
Applicability: All buildings that have onsite battery storage with no photovoltaic system or lowrise multifamily buildings served by community solar.
Definition: Standalone batteries are charged from the grid during low system load or TDV hours and discharged to support the building load and/or grid during peak time or high TDV hours.
Units: none.
Standard Design: Standalone batteries are not modeled in the standard design.
Standard Design: Existing Buildings: Same as the proposed.