Step 3: Equipment Involved

The essential elements of a residential solar system.

Solar panels

While sunny states like California lead the U.S. in solar installations, Connecticut homeowners still have much to gain from going solar.

Solar panels collect and convert the sun’s energy into electricity. They are a key component of a solar panel system. Most commonly available panels today are either:

  • Poly-crystalline solar panels, or
  • Mono-crystalline solar panels

The key difference between poly and mono crystalline panels are their efficiency — i.e., how much electricity they produce — and their cost. The more efficient panels tend to cost more. Typically, mono-crystalline panels are more efficient and thus more expensive than poly-crystalline panels.

Inverters

The cells in your solar panels collect the sun’s energy and convert it into direct current (DC) electricity. Most homes and businesses, however, use alternating current (AC). To change the DC current from your panels into usable AC current, it is passed through a device called an Inverter. The resulting electricity can be used by you or fed back into the power grid

There are three basic types of solar inverters:

String or Centralized inverter: If your system uses a string inverter, a single inverter is used to connect your entire array (or set) of solar panels to your electrical panel. String inverters tend to be cheaper than microinverters. One drawback of string inverters is that if one of the panels stops producing electricity—even if it’s because of shading of panels, it can bring down the performance of the whole system.

Microinverters: With microinverters, there’s one installed at each solar panel. This allows each panel to maximize production. Because of this, microinverters are preferable in situations where one or more of your panels may be shaded at different times of day or if some panels are installed facing different directions or pitch angles. The cost of microinverters tends to be higher than string inverters.

Power optimizers: Systems that use power optimizers are a hybrid of microinverter and string inverter systems. Like microinverters, power optimizers are installed at each panel. However, instead of converting the DC electricity from the solar panels into AC electricity, the optimizers 'condition' the DC electricity before sending it to a central inverter. Like microinverters, they perform well when one or more panels may be shaded or if panels are installed facing different directions. Power optimizer systems tend to cost more than string inverter systems, but less than microinverter systems.

Mounting systems

Mounting systems are used to attach your solar panels to your roof or on the ground. They also allow you to position your panels at an angle that is best for capturing the sun’s rays.

To perform at their best, solar panels should face south and be installed at an angle between 30 and 45 degrees — the higher angle is more suitable in northern regions of the United States.

Although these are the optimal conditions, panels facing east or west and at a pitch angle of 5 degrees or more will still work well, but will produce 10-20% less electricity than those installed under perfect conditions. Solar panels installed in less than optimal conditions can still make great financial sense.

Panels can be mounted in two ways:

  • Fixed mount: Where the panels remain stationary.
  • Track mount: Where the panels are installed on a track that allows them to “follow” the sun’s position as it changes during any given day (single-axis track mounts) and also follow the sun during the changing seasons (dual-axis track mounts).

Performance monitoring systems

A monitoring system provides you with detailed information about the performance of your solar panel system. It allows you to:

  • Measure and track the amount of electricity your system produces on an hourly basis.
  • Identify any performance issues and quickly fix any problems and ensure that you maximize the electricity production of your solar panel system. Since a large part of the financial benefit of your solar panel system is tied to its production, a monitoring system also ensures that you maximize your investment returns.
  • Maximize the value you will receive for your solar panel system when you sell your home or commercial building powered by solar panels.
    Some solar contractors may charge extra for installing a monitoring system, but over the life of the system, it can provide a lot of value.

There are two types of monitoring systems:

  • On-site monitoring: The monitoring device is physically located on your property and records the amount of electricity produced.
  • Remote monitoring: Your solar PV system transmits its performance data to a monitoring service that you can access online or via mobile devices.

The difference between fixed vs. track mount systems

Fixed mounts are the least expensive and the only option if you are installing your panels on your roof.

Track mounts are expensive, but they allow you to increase your panels’ electricity production by 30% or more. Track mounts are only suitable for panels installed on the ground. Because they have moving parts, track mounts generally require more maintenance. This, as well as the additional cost of the track mount may not justify the gains you will achieve in electricity production, so you’ll need to run the numbers before deciding to use track mounts.

Track mounts are generally suitable for situations where you have limited space to install solar panels and you would like to maximize the electricity production from a limited number of solar panels.

Content credit: What is a Solar Panel System? originally appeared on EnergySage, the online solar marketplace.

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