NEW PROVISIONS FOR ROOFTOP SOLAR PANELS AND NEW STATE REQUIREMENTS

Effective January 1, 2020, the California state mandates the installation of the solar systems on most of the new construction homes up to three-story high. Currently, there are no mandates on commercial developments to install solar panels in the building process. California is considered to be a sunny state for most of the year and therefore it is conducive for such an energy source. There are many benefits that old and new structures can take advantage of solar energy. The greatest benefit is the reduction in money spent on electricity and other electric power expenses by the production of this clean energy. Also, building owners can take advantage of the tax credits offered by the state of California by converting to solar energy. For eligibility, visit the state website and review the current terms and conditions.

Once it is determined that the building owners desire to install a photostatic system on the roof, it is very important to hire electrical and structural engineers to assist with this process. Electrical engineers will be able to determine the energy required to convert the current annual electric usage to solar energy and provide panels accordingly.

The electrical engineer will also have to prepare a Title 24, part 6 which is a new part that comes with this mandate. Once the number of panels is determined and the number of inverters is decided by the electrical engineers, the structural engineers will need to figure out how to install these systems on the existing roof framing system.

In residential structures, these panels are installed right on top of the roofing finish with unistrut framing system and it is anchored to the existing roof rafters and roof framing. In other structures, the structural engineer may require building frame structures to install these panels on. This is very common in parking structures and high parapet structures to avoid the shadow of the parapet and attract more sunlight by being elevated on these frames. Other types of installation can be done on the ground level in open parking lots creating shaded parking for cars, especially during hot summer days.

Current building codes realized the demand for these PV panels and added specific provisions that will guide structural engineers in deriving wind loadings and wind pressures different than other structures and different than previous code editions. This is now available in the latest ASCE 7-16 building code in chapter 29, which provides the exact wind loadings for the described above types of installations. This section of the code details the different types of pressures based on the installation methods. For example, the wind pressure will be higher for panels that are installed near the building edges as suppose to those panels installed at least a distance equal to the height of the structure above ground from the edge of the buildings. Also, wind loadings vary based on whether the panels will be installed directly on the roof framing or installed on a frame structure designed to elevate these panels for more sunlight exposure.

At this point, it is known that any new residential buildings will need to have a 100% clear energy source. It is unknown as to when commercial buildings will be required to have these panels installed for new construction. In any case, it is recommended to consider the installation of these panels moving the demand towards cleaner energy sources.