Continuing its trajectory toward meeting its ambitious AB32 goals, California continues to attack carbon emissions within the built environment through its 2022 Energy Code. In addition to more electric-friendly baselines and implementing a metric for source carbon reduction, the 2022 code will require solar photovoltaics for most buildings. In the 2019 energy code, a solar PV requirement was introduced for most new low-rise multifamily buildings and single-family homes. Now, solar photovoltaics will be required for new nonresidential and multifamily residential buildings four stories and greater permitted on or after January 1, 2023.
1. Most buildings will soon require solar.
The requirements, which appear in a new section of the Building Energy Efficiency Standards, Section 140.10, apply to most nonresidential occupancies. Requirements for multifamily buildings four stories and greater (high-rise residential) appear in the newly created multifamily section of the code. Like low-rise PV requirements, system sizes are prescribed, with prescriptive sizes based on the power (kW) of a system, not the energy (kWh) that a system could be expected to produce. Through efficiencies in the building, it is possible to reduce the number of panels required. However, the converse is not true: building efficiency goals cannot be circumvented by providing more PV. Community solar electric generation is still permitted to meet all or a portion of the PV requirement as per the conditions of Section 10-115. Requirements for solar ready buildings still exist, but text added to the section clarifies that it only applies to buildings “which do not have a photovoltaic system installed.”
2. There are two ways to calculate solar requirements – CFA and SARA.
Low-rise multifamily and single-family requirements are essentially unchanged from the 2019 code. For high-rise multifamily and nonresidential buildings, there are two options to meet the prescriptive system size. Projects are allowed to choose between the smaller of the two resulting system sizes:
- CFA (Conditioned Floor Area) – The first option is based on the conditioned floor area. It is a straight W/ft2 ratio, with coefficients that vary by climate zone and occupancy type. Using the CFA method, high-rise residential in most climate zones will need to install 2.21 W/ft2; retail and grocery will need 2.91 W/ft2.
- SARA (Solar Access Roof Area) – The second method is better suited for taller buildings. Prescriptive PV sizes are based on the Solar Access Roof Area. SARA includes unoccupied roof space capable of structurally supporting a PV system that receives more than 70% annual solar access. The code accounts for obstructions that are both part of and external to the building. The SARA system size, for all occupancies and climate zones, is determined by multiplying the SARA by 14 W/ft2.
3. Battery storage systems will be prescriptively required for many new buildings.
Early analysis for high-rise multifamily shows that most buildings with unconditioned corridors will require slightly less PV per unit than low-rise multifamily. However, these new codes for nonresidential and high-rise multifamily have also introduced battery storage requirements. Like PV system requirements, sizes of battery storage systems are also prescriptive, and sizes are based on the calculated PV sizes (lesser of the CFA and the SARA method). Multipliers will vary by occupancy type but not by climate zone. For high-rise multifamily and retail, that multiplier is 1.03 Watt-hours per Watt of PV.
4. Early energy modeling can help.
It is possible for a project to receive its building permit without a solar and battery system designed or specified in the energy model. California-compliant modeling software will calculate PV and battery requirements if a system is not specified. Systems calculated this way must meet the California Flexible Installation (CFI) criteria which allows for installation between 150 and 270 degrees of North, and pitches between 0:12 and 7:12. This method has its advantages, but it does not allow projects to weigh options. It is anticipated that, through energy modeling, increases in PV will be able to decrease the battery storage and vice-versa.
Early energy modeling can help to weigh efficiency options versus PV requirements as well. Because of this, it will be vital to get your energy consultant involved early in design; VCA Green is just that partner. We have a proven track record of saving clients’ money through careful energy modeling. VCA Green can also help to select the solar design-build that is right for your project. As solar consultants, we solicit and evaluate solar proposals from multiple sources. We translate their proposals into language that is easily understandable so that you can select the right provider with confidence. For energy modeling or solar consulting services in anticipation of the upcoming solar PV requirements, contact Moe Fakih below.
Contributing Writer: Glen Folland, Director of Sustainability
Moe Fakih, Principal