Archive: Aug 2021

Solar Inverters: String Inverter vs. Microinverter vs. Power Optimizer

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When choosing from different solar panel options, the type of inverter you select is crucial to overall performance. Solar inverters convert the direct current (DC) energy that solar panels generate into more compatible alternating current (AC) energy that powers the building. Depending on your specific needs, you can choose from three main types of inverters, including string inverters, microinverters, and power optimizers. Each inverter’s importance may vary for different types of photovoltaics (PV) installations. 

Here we’ll review the advantages and disadvantages of these three types of inverters to help you determine which is right for your installation.

String Inverters

String inverters are the most cost-effective inverter option. Solar installers typically recommend using these if a roof has limited shading over the course of the day and doesn’t face multiple directions. However, today’s innovations make these inverters more suitable for a larger number of applications.

With this type of inverter, solar panels are arranged into groups connected by strings, and users can connect several strings of solar panels into one centralized inverter that converts DC energy to AC energy. While string inverters offer plenty of reliability as a decades-old technology, it’s not appropriate for every installation.


The combined low cost and ease of installation make string inverters a popular option for many. These inverters can be paired with power optimizers and are suitable for both residential and commercial applications if no shading problems are present. 


Despite the appealing advantages of string inverters, there are a couple of potential disadvantages to consider. First, if one panel experiences decreased output, this causes output to drop for every panel in the string. Generally, string inverters are only ideal when panels see full sunlight throughout the year.


Another popular option is a microinverter, which a growing number of installations use today. Normally, systems using microinverters install them on the back of the solar panel, where they convert DC energy into AC energy without any need for a separate string inverter. Installers often mount microinverters onto the backs of solar panel backs, but it’s also possible to place them beside the panel on a solar racking system.


One advantage of microinverters is that poor-performing panels won’t compromise the entire PV system’s production capabilities. It’s also easy to determine when an individual panel needs maintenance or a complete replacement.


Microinverters come with a couple of disadvantages that make them unsuitable for certain installations. Microinverters are more expensive than string inverters. In addition, individuals need to access the roof to maintain or replace these inverters due to their placement on the panels.

Power Optimizers

Power optimizers offer similar benefits to microinverters, and they often serve as a sufficient compromise between string inverters and microinverters. Much like microinverters, power optimizers are installed on each panel. What makes them different is the way they convert DC electricity to AC electricity. Rather than converting energy directly at the panel site, power optimizers send the DC energy to a string inverter for conversion.


Power optimizers and microinverters share similar benefits. Both of these inverters normally have a 20 to 25-year warranty. They also come with the added benefit of lower costs compared to microinverters.


Power optimizers are also similar to microinverters in their disadvantages. Maintenance and replacement costs will be higher because of power optimizers’ location on rooftops. Additionally, they endure regular exposure to the elements, which can lead to eventual wear and tear.

Make the Right Choice of Inverter with Nine Fasteners, Inc.

Based on your installation’s individual requirements, you’ll need the right inverter. At Nine Fasteners, Inc., we can help you determine which inverter type is best for your PV installation. If you would like to find out more about our capabilities and how we can help you, contact us or request a quote today. 

How to Design a Solar PV System

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Compared to many traditional power generation solutions (e.g., combustion systems), solar photovoltaic (PV) systems are more eco-friendly. However, they must be designed and constructed properly to produce enough electricity for the intended application. Otherwise, they may not work effectively and/or efficiently. 

Given the numerous factors that must be considered when designing and constructing a solar PV system, some industry professionals may find starting a solar PV system project to be daunting. That’s why the solar panel experts at Nine Fasteners have put together the following guide. It provides an overview of how to design a solar PV system to help readers navigate the design process successfully. 

What Are Solar PV Systems?

Solar PV systems—sometimes called solar panel systems—utilize specialized panels made with photovoltaic cells to collect sunlight and convert it into direct current (DC) electricity. The electricity they generate can be stored for future use, used directly, fed back into the grid, or combined with energy from other power sources, as needed. These systems are employed in a wide range of applications across the industrial, commercial, and residential sectors, from crop growing and livestock care to powering homes and businesses.  

Key Components of Solar Panel Systems

As suggested by the name, a key component of solar panel systems is the solar panels, which contain the photovoltaic cells that generate electricity from sunlight. While they are the most visible part of the system, there are many other components that are equally critical to the system’s functionality, efficiency, and safety. For example: 

  • Solar array mounting racks. These components ensure panels have a sturdy connection that keeps them in the proper position for the greatest sun exposure. 
  • Array DC disconnects. These components allow service technicians to manually stop electricity from reaching the inverter to charge down the system for maintenance. 
  • Power meter, utility meter, and kilowatt meter. These components measure the amount of power generated by the system and the amount of power it uses from the utility grid. 
  • Backup generator. This component serves as a secondary power supply when the solar panels cannot generate enough electricity to meet demand. 
  • Breaker panel, AC panel, and circuit breaker panel. These components serve as fail-safes that protect a building’s circuit from potential electrical damage. 
  • Charge controller. This component protects electrical systems from variable electricity influxes.
  • Wire management clips. These components help keep wires organized so they can be easily traced and identified when needed.
  • Solar hardware. These components (e.g., inverters) make solar PV systems easier to manage. 
  • Electromechanical components. These components vary depending on the solar PV system design. They can include motorized devices and motor-driven battery systems or computerized systems and control devices. 

Basics of Designing a Solar PV System

When designing a solar PV system, some of the basic principles to follow include:

  • Choose a system that meets the power needs. Criteria may include better energy efficiency, smaller environmental impact, or lower investment costs. The PV array should be sized and oriented to suit the expected energy demand. 
  • Check the installation site. The installation site should be large enough to handle the system chosen. Additionally, the PV array should be located in an area within the installation site that is not shaded by natural or manmade structures.
  • Consider relevant industrial/application requirements and restrictions. The system should be designed with regard to all applicable building and electrical codes and local utility interconnection requirements. Additionally, the design should minimize electrical losses due to wiring, fuses, switches, and inverters and feature a properly housed and managed battery system. Any outdoor equipment should be made from sunlight and weather resistant materials to ensure durability and longevity.

Important Design Considerations for Solar PV Systems

Some of the factors that should be considered when designing a solar PV system include: 

PV Electrical System Type

There are two main types of PV power systems for residential use: grid-interactive systems with no battery backup capabilities and grid-interactive systems with battery backup capabilities. The type of system chosen should suit the power needs of the intended application. 

Mounting Option

The two most commonly utilized mounting solutions are roof mounts and ground mounts. Each offers unique advantages and disadvantages that make them suitable for different applications. For example, roof mounts allow solar panel arrays to be mounted onto existing space, while ground mounts enable systems to be mounted anywhere on the property. 

System Output 

The system output is largely dependent on the intensity of sunlight that hits the solar panel surface. It can differ from day to day as well as throughout a single day. Other factors influencing system output include temperature, dirt/dust accumulation, mismatch/wiring losses, and DC to AC conversion losses.

Installation Labor Effort 

The amount of effort it takes to install a PV system depends on the system and installation site. For example, non-battery systems are easier to install than battery systems since they do not require as much wiring for the critical load subpanel. The latter can require between 50–100% more installation time.

Cost Reduction Incentives 

Some local, state, and federal organizations offer financial incentives that reduce the cost of solar PV systems. They can decrease the total cost of a system by 30–50% or more, depending on location. 

Estimated Electrical Energy Savings 

A key benefit of solar panel systems is reduced electric utility bills. This savings can be calculated by multiplying the amount of energy in kWh a PV system may produce annually by the current utility electric energy rate.


Numerous factors influence the size of the solar PV system needed. The first step in sizing the system is determining the power consumption demands, which necessitates calculating the total amount of watt-hours per day for each device used and the total amount of watt-hours per day needed from the photovoltaic modules. The results of these calculations affect the sizes of the PV modules, inverter, battery, and solar charge controller needed for the system.


It is essential to maintain complete documentation for the system. The documents should include an owner’s manual and copies of relevant drawings, all of which can help in future system maintenance operations. 

Learn More About Solar PV Systems From the Experts at Nine Fasteners

Want additional information on how to design a solar photovoltaic system? Ask the experts at Nine Fasteners! As an experienced solar panel hardware manufacturer, we can help you understand how different components can influence the performance of your system. Additionally, if you need wire management clips, solar hardware, fasteners, or electromechanical/computer components for your system, we’ve got you covered. Request a quote for product or pricing details.