How To Find the Optimal Layout for A Commercial Solar Array: Design Tips

How To Find the Optimal Layout for A Commercial Solar Array

A report by the US EIA found that between November 2020 and November 2021, the electricity prices increased by 6.1% for the residential sector and 7.6% for the commercial sector. The monetary impact of this inflation can be minimized or even completely avoided if homeowners and businesses start generating their own electricity. To make this happen, the best way is with solar panels. 

However due to the limitation of the building roofs, efficient use of the solar panels along with installation plays a key role in minimizing the power bills. This can be achieved with assessment and design by a solar professional. An efficient layout can result in lower installation costs, which in turn will mean shorter payback period and higher ROI for building owners.

Two buildings using the same number of solar panels can achieve different savings if the roof space is used more efficiently. To do this, the following are the main factors to consider when designing a commercial solar array layout.

Avoid Shadows: The #1 Priority

We all know that the electricity output of solar panels depends on how much sunlight is reaching the panel surface. While this may seem simple and obvious, that’s not all there is to it. The sun’s position keep changing, which can be due to the current hour but also because of the season. Due to this, the same part of roof can be very sunny or completely shaded, depending on when you look. 

This is where solar engineers play an important role. They use design software that simulates sunlight and shading throughout the year. This allows them to identify the best possible areas for installing solar panels. 

Flat Commercial Roofs Allows Simpler Solar Installation

The type of racking system required for installing the solar panels depends on the roof material and slope. For commercial buildings with flat roofs, a ballasted racking system is used which uses heavy bases to hold the solar panels in place. On the other hand, for sloped roofs, holes need to be drilled to attach the panels onto the mechanical supports. 

For commercial buildings with both flat and sloped roofs, flat areas can be prioritized to make the array layout and installation simpler. Simpler maintenance is another benefit of flat roofs as they can be inspected without having to walk on steep or sloped surfaces. 

Leave Enough Space for Other Mechanical Equipment

Generally, roofs contain mechanical equipment like cooling towers and roof vents, which need regular maintenance. Keeping in mind that the inspection professional needs to carry tools for the maintenance, solar panels should not get in their way to avoid any damage. 

Speaking of maintenance, solar panels too need maintenance. An efficient solar array layout allows enough space for maintenance to be carried out. Fortunately, solar panels are less demanding that other electricity generation systems. 

Large Solar Panels Save on Racking and Labor

Solar panels come in multiple sizes, but the most common ones are the 60 cell and 72 cell modules. The specifications and dimensions may vary depending on the manufacturer, but both the module, 60 cell and 72 cell, have the same width. The 72 cell solar panels are about 20% taller.

Many solar brands have started using half cells with a much more efficient design. Instead of the normal 60 cells or 72 cells, they have 120 half cells or 144 half cells. 

Generally, the 72 cells or 144 half cells solar panels save on installation costs for the following 2 main reasons:

  • Since they have the same width as the 60 cell solar panel, the amount of racking required per panel remains the same. 
  • Also, the total number of cells is higher which optimizes the racking and labor costs.

Plans for Expansions and Renovations Must Be Considered

The high quality solar panels have a service life of 25 years or more. However, there might be instances where the roof needs to be modified. In such cases you will be forced to relocate the solar panels. This brings in additional costs. To avoid such expenses, picking a roof space that will not be renovated or modified is the best option. 

Michael Tobias

Michael Tobias

Founder & Principal at NY Engineers
He is the principal and founder of NY Engineers. He leads a team of over 50 MEP/FP engineers. Although New York Engineers main headquarters are in NYC and Chicago the business has led over 1,000 engineering projects in New York, New Jersey, Connecticut, Pennsylvania, Florida, Maryland, and California, as well as Malaysia and Singapore. Michael is an advocate for green technology and energy efficiency, and approaches engineering as a vehicle to raise the quality of life.

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