Retail stores, in standalone and strip mall locations, offer prime real estate for rooftop solar installations. With the right amount of space and correct use of materials, rooftop installations can help reduce operations costs up to 50 percent.
Factors to consider when planning a retail rooftop installation are timing and safety, feasibility, electrical structure and materials. Based on approvals and budget availability, timing to install a retail solar system in the Northeast is usually recommended between July and December. With this schedule, planning is pertinent because of the busy retail holiday season at year-end. Try and plan the time of interconnection, which requires a system shutdown, before the end of October.
Connecting the solar panels to the existing electrical system can be difficult with the operation schedule of a retail establishment. Businesses must have power to remain open, so taking the store completely off-grid is often not a reality. To avoid a complete loss of power, the solar installer must provide a plan to connect the business to generators as an alternate power source. Interconnection must be performed with great precision to avoid serious business or legal consequences.
Many commercial buildings are topped with a large, open-layout roof that has little or no slope, which is one of the factors that make commercial locations perfect for solar installations, but that doesn’t mean there are no roof considerations.
When assessing the roof for an installation, the construction team should work closely with the roof manufacturer to ensure that warranties are not voided. Likewise, the installation and planning teams should review a full explanation of the project and all planning documents with the roof manufacturers. The quality of the roof’s membrane (used to prevent weather damage) must also be considered. If the membrane is lacking in any way, it should be repaired before construction begins.
Between the racking and the panels, a solar installation puts a lot of additional weight on an existing rooftop. Working with inspectors and roof manufacturers ensures there are no safety hazards in regard to weight restrictions.
Next, inspections must take place to assess the wiring and capacity for the building. Considering restrictions first allows for plans to be made for the amount of voltage the current electrical system can handle and how many panels can be safely installed.
After the specifics of the rooftop are known, a formal in-person survey of the roof must be conducted to address possible challenges and obstructions to gain the most accurate and detailed information for planning location and materials. Through this process, obstructions can be marked on detailed maps to ensure there are no additional costs or installation difficulties down the road. The formal survey will address concerns and problem areas such as pipes, ducts, vents and sloping on the rooftop and avoid these when deciding on the placement of the installation.
At this point in planning, surveyors can address the best points of access for the roof. From the top, they can see best places to store materials on site and all possible challenges to getting materials up to the roof. Without these notations, the build-time will be extended and cause excess movement of the materials.
In active stores specifically, safety of the customers and staff are of great importance. To ensure proper protocol is followed, solar builders must work closely with store and building management teams. Regular meetings should be held with the construction leads and managerial staff to address any changes and provide updates on progress. The first meeting should outline any areas the construction crew should avoid, where building materials will be housed and the most appropriate roof access points for lifting materials. The installer can also participate in safety courses provided by the client. This ensures all solar team members will be abiding by all client procedures in addition to the safety training provided through their employer.
At this time, the location of the electrical access points should also be noted for further electrical reviews.
Wiring for Success
At this point, the planning team should be well-versed on the location of the electrical box and main connection points. The site of the box should be cleared of any obstructions and made easily available for connecting the installation. Clearly noting the location will eliminate unnecessary movement of materials throughout the assembly process.
Next, the planning team will meet with an electrical expert to address the amount of power that can be added into the existing electrical infrastructure. Noting the space available for connection also becomes crucial during this review. Not having properly located connection sites would cause delays in interconnection. Any additional materials that will be needed to ultimately connect the solar energy source to existing electrical units should be ordered immediately. In addition to the inspection done by the construction team, certified electrical inspectors must be used through the city where the retail store is located. Inspectors will also require full disclosure and planning documents for the project.
This step requires a strategic plan individually set for the roof conditions and financial needs of the client. Most often, string inverters are used to minimize the number of mounting solutions and reduce cost. Procuring materials that are prefabricated, such as struts and racking systems, will save a lot of time and man hours throughout the project.
With the introduction of PVC-coated materials, such as conduit, weight can be significantly lessened. This comes into consideration not only for weight restrictions, but for the physical placement of materials in the correct location on the roof. Avoiding extraneous heavy lifting for the construction team can speed up production times and ultimately save the client money.
Planning for value is extremely important in the material procurement process. Using the newest, most effective materials is always the goal for installers, but this doesn’t always fit within the budget. Reviewing different manufacturers and brands will often surface pricing alternatives for comparable equipment.
In today’s solar market, there are a number of ways to finance and personalize an installation to best fit any business’s needs. As prices drop throughout the industry, retail solar installations will continue to rise and become top of mind for retail’s finest, looking to take part in this money-saving, green initiative.
Mike Kushner is director of construction for Pro-Tech Energy Solutions.
— Solar Builder magazine