Sizing of a Solar System the Right Way

Determining Size of System

When Sun City Solar designs a solar array for a home or business, there is no one-size-fits-all approach to the sizing of a solar system. Every home and business has unique needs, budget, and available space for solar. Our Solar Advisors will discuss your needs, goals, and budget for solar and perform a site survey to determine the best location for a solar array.

Most solar owners want to offset as much of their electric bill as possible. To determine the sizing of a solar system that eliminates your electric bill starts with examining historical electrical usage. For the proper sizing of a solar system, your Sun City Solar Advisor will need a minimum of 12-24 months of historical electric usage. This information can be obtained from a past electric bill showing a historical usage chart, the utilities online service portal, or directly contacting the utility customer service department.

If you have a utility bill on hand or know your average monthly electric costs, contact us, and we can help you determine what size system you will need.

Net Metering

Net Metering transfers excess power generated from your solar array to the public utilities power grid. In states that have approved Net Metering, the customer is normally given credit for the extra power sent onto the grid. At the end of the month, the utility will “net” both the usage consumed from the grid along with the excess power sent back to the grid. This allows a home or business that produces excess solar during the day to receive a credit that can then be used at night when solar is not producing.

In states with approved Net Metering, like Arkansas, Sun City Solar can size a solar system that will eliminate 100% of your annual electric usage. A system is designed to overproduce during the day allowing credits to be used at night or on cloudy days, therefore zeroing out the annual usage needs.

In states that do not have approved Net Metering or do not credit for excess production, like Oklahoma, Sun City Solar can design a system that will cover a portion of the home’s usage but will not be so large that it overproduces. In these states, batteries are a great option to store any excess production. In addition, add-on battery storage can be used for emergency backup power when the grid loses power or offset some of the usages of the home during non-production times for solar.

Meter Aggregation

Utilities and states that allow net metering, will also allow meter aggregation. Meter aggregation is the ability to cover the usage on multiple utility meters with one solar array. If you have multiple homes, business locations or buildings on separate meters, Sun City Solar can design a system to be installed on the best location for solar production and push any excess credits produced to other meters on property you own.

Not all locations are great for solar production due to potential shade issues or lack of available roof/ground space. By selecting the best location for solar production and aggregating multiple meters allows Sun City Solar to design a system that can maximize energy production while eliminating the cost of installing an individual system on every property.


Sun City Solar can design a system to fit any budget. Many homeowners start with installing a small system with plans to add additional solar in future years. Sun City Solar can size a solar system on the front end that can handle future expansion easily and affordably.

Factors that could affect system size

Finding the right location to install your solar array is vital to getting the maximum energy production out of your investment. By avoiding areas that may produce shade on the array during the day, will ensure your panels are exposed to full sunlight during the crucial peak hours of the day.

Shade from nearby trees, buildings or even your home’s chimney can have a major impact on the energy produced from the array. Sun City Solar can perform a site survey to determine the best location to avoid exposure to shade.

Other factors that could limit the size of the solar array on your roof is the shape of your roof and the amount of roof penetrations or obstructions. Roofs come in all shapes and sizes and most have several pipes, vents, skylights and chimneys that have to be avoided. In addition, a roof needs to be positioned in a general southern direction to maximize daily production.

If a site visit by a Sun City Solar Advisor determines your roof has too much shade or is not suitable for a solar array, your Advisor can discuss other options such as installing a ground mount.

See also the article on “Battery Bank Sizing Considerations”.

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