Since 2008, California has seen a substantial, steady increase in photovoltaic (PV) array installations. The trend has been spurred and supported by California’s statewide Zero Net Energy goals, including the California Energy Commission (CEC)’s “Solar Ready” requirement, which was added to Title 24 in 2013.
The 2016 code, which took effect in January of this year, had some minor updates, but the overall intent is the same: design new roofs with conduit pathways and clear, available space for a solar system regardless of whether or not the building owner expects to purchase a system. The requirements apply to both residential and non-residential new construction projects.
The foresight has proven effective, especially as we see the price per installed watt of solar electric generation decrease. The average cost for residential PV in 2010 was $7/watt; five years later in 2015 it had dropped to just under $4/watt. Today you can find companies advertising residential installations for under $3/watt! This means owners of residential and commercial buildings constructed after 2013, who in the recent past might not invest in solar, are now doing so and have roof space available already, thanks to the solar-ready requirement.
Whether your project triggers “Solar Ready” by code or if you are just getting prepared, here’s a summary to give you a head start on what the 2016 Solar Ready requirements look like.
Solar Ready Non-Residential
Applicable to:
· Hotel/Motel less than 10 stories
· High-rise multifamily less than 10 stories
· All other nonresidential buildings three stories or less
The Solar Zone, an unshaded, obstruction-free area can be located on:
· Roof
· Overhang
· Roof of another structure (within 250 feet)
· Overhang of another structure (within 250 feet)
· Covered parking installed within the project
· Trellises, arbors, patio covers, carports, gazebos…
Minimum Solar Zone (SZ) Area
· No less than 15% of total roof area (subtract skylights)
· Can be multiple subareas with no dimension less than 5 feet
· If total area ≤ 10,000 SF each sub-area must be at least 80 SF
· If total area > 10,000 SF each sub-area must be at least 160 SF
Note: If the site has significant shading, exceptions are available.
Orientation
· If the roof pitch is greater than 2:12, then the roof must be oriented south or west (between 110 and 270 degrees of true north)
· If the roof pitch is less than 2:12, orientation requirements do not apply
Shading
· Obstructions (vents, chimneys, roof mounted equipment) must have a horizontal distance (D) of at least two times the height difference (H) between the highest point of the obstruction and nearest point of the solar zone, or D ≥ 2H (see diagram below)
· Obstructions north of the solar zone are not subject to horizontal distance requirements
Interconnection Pathways
Construction Documents must indicate:
· Location for inverter and metering equipment
· Pathway for conduit from Solar Zone to the point of interconnection with the electrical service. No installation requirement, just drawings to show conduit location
Or
· A pathway for routing of plumbing from Solar Zone to Water Heating system, no requirement to installing piping
Fire Code Access Requirements
· PV arrays shall not have either axis dimension exceed 150 feet
· PV arrays shall provide a 6’ wide access perimeter around edges of roof
· Smoke ventilation options must exist between array installations and next to skylights or smoke/heat vents
Solar Ready Residential
Applicable to:
· Single Family Residences located in subdivisions with ten or more single family homes
The Solar Zone, an unshaded, obstruction-free area can be located on:
· Roof
· Overhang
Minimum Solar Zone (SZ) Area
· The SZ’s total area will be no less than 250 SF
· Can be multiple subareas with no dimension less than 5 feet
· If total area ≤ 10,000 SF each sub-area must be at least 80 SF
· If total area > 10,000 SF each sub-area must be at least 160 SF
Orientation, Shading, Interconnection and Fire Code: Similar to non-residential
Implementation
The Solar Ready code provides an important baseline for any business or homeowner to install PVs after a project’s completion, an increasingly likely occurrence given the falling prices of solar panels. For those with bigger renewable energy goals, maximizing roof area while understanding the limitations of orientation, shading and fire access will help avoid frustration at installation time.
If you’d like assistance with solar ready compliance or calculations, let us know!