SOLAR INVERTER

What is a Solar Inverter?

Solar panels produce direct current (DC) electricity. Inverters change this DC power into alternating current (AC) power, which is the type used to run your appliances and lights.

Microinverters and power optimizers are smaller and more expensive than string inverters, but they allow for panel-level maximum power point tracking and enable easier troubleshooting.

Solar Panels

The large black solar panels that you see on roofs and at homes and businesses are a collection of solar cells (also called photovoltaic cells) made of silicon semiconductors that absorb sunlight and convert it to electricity. Each cell has positive and negative terminals, which are connected together in a wired system known as series wiring.

Solar panels produce direct current (DC) electricity but most household appliances use alternating current (AC). The inverter installed with your solar power system transforms the DC into AC to run your home’s electric appliances and to feed any excess energy back to the grid.

Inverters are often selected to have a maximum power output lower than the maximum power produced by your solar panel array, which is fine because your solar panels rarely reach their peak production capacity on most days anyway. This limits the “clipping” of power production that would otherwise overtax your inverter and reduces your system’s productivity.

You can also install micro-inverters on each of your solar panels to bypass the need for a central inverter. These inverters convert the DC electricity from your solar SOLAR INVERTER panel into AC, allowing you to monitor the performance of each one individually. They can even connect to the Internet via Wi-Fi or hardware Ethernet connections, letting you view your energy usage and production on your smartphone app or computer desktop.

Batteries

The battery stores the power your solar panels produce, keeping it ready to recharge in the event of a grid outage. Depending on the type of battery, it can last up to 10-15 years. It is important to monitor the health of your batteries. The lifespan of the battery depends on a number of factors including usage patterns, environmental conditions, maintenance, load, capacity and its Depth of Discharge (DoD). Keeping your battery at an optimal level will maximize your backup time and increase its longevity.

The most common battery on the market is lithium, which is well-understood and safe. Lithium batteries work by moving lithium ions through the electrolyte, which creates free electrons. These free electrons are used to charge and discharge the battery, which can be repeated hundreds of times. There are also multiple other deep cycle battery chemistries that can be used for solar energy storage, such as nickel-manganese-cobalt, lead acid and lithium iron phosphate.

Batteries are sensitive to temperature and must be stored in a temperature-controlled space to ensure their lifespan. During extreme heat, chemical reactions within the battery accelerate, shortening its lifespan and reducing performance and efficiency. Similarly, cold weather slows the chemical reactions and can impact the lifespan of your battery. The more a battery is charged and discharged, the shorter its lifespan will be.

Inverter

The inverter is the heart of your solar system. It changes DC power into alternating current (AC) and sends it into your fuse box solar inverter off grid or distribution board. It might also feed excess electricity back into the grid, or to a battery storage system, depending on your solar system configuration and design.

The sun’s energy runs around and bumps electrons between layers inside your panels. This creates electric current, usually in the direct current (DC) format. Your home needs alternate current, which your inverter converts by rapidly shifting the direction of the DC input power.

Your inverter should have a high efficiency rating and a pure sine wave output to minimize harmonic distortion, which can affect the performance of sensitive electronics. Look for an inverter with a total harmonic distortion (THD) of 6 percent or less.

Some inverters are designed to work with three-phase power, which is common for large commercial or industrial systems. A three-phase inverter can reduce the need for energy storage by transferring the panel output to different wires during zero-crossing periods, which occurs twice per cycle at 50 or 60 Hz.

Some inverters come as all-in-one units that combine a photovoltaic array, batteries and utility grid connection. This configuration is often referred to as a grid-tie or on-grid system. Customers with this type of solar system can build credit to offset their utility bills, or, depending on where they live, get paid a feed-in tariff for the surplus electricity they export to the grid.

Monitoring

A good solar monitoring system will allow you to check on the status of your system from anywhere with internet access. It will give you the peace of mind that your solar installation is doing what it’s supposed to do. It can also help you avoid problems, such as an unexpectedly high electricity bill from increased power consumption during the first few weeks of your solar transition.

Modern smart inverters have built-in energy monitoring capabilities that collect and transmit data on parameters like power production to a web portal or mobile app. They also enable a variety of grid-supporting functions, such as communication and frequency control.

The most popular monitoring solutions are software-based and connect to your inverters via a virtual private network (VPN) or a cellular modem. Generally, the latter method requires you to purchase a cellular data plan that’s separate from your phone or tablet’s data plan.

The best option for most homeowners is a standalone solar monitoring system with an intuitive interface that works on most smart devices. This allows you to check on your solar system in real time, monitor energy consumption, track your environmental benefits & history of power output and more. The most popular system is Enphase’s system monitor, which seamlessly integrates with the IQ microinverter systems and provides module-level assessments in 15-minute intervals. It’s a great way to quickly identify any modules that may not be producing as expected, which could lead to costly repairs or lost energy.