Solar Panel Inverters

A solar panel inverter is a device that converts the direct current (DC) output of a solar panel into alternating current (AC). Inverters play a crucial role in any solar energy system and are often considered to be the brain of the project. After the panels themselves, inverters are the most important equipment in your solar power system. So, how do these devices actually fit in a residential solar system? 

Power conversion

As the name suggests, an inverter converts direct current to alternating current, which is the standard used by all electrical appliances. Basically it acts as a gateway between direct current and alternating current.

Power optimization

It maximizes the energy harvest from the solar panels. It does this by isolating individual panels in order to increase energy output, hence improving the overall system performance.

Monitoring and protection

An inverter keeps track of the energy yields of the solar system and its electrical activity and signals when there is a problem. This information can be viewed on the device itself or from another location if suitable communication technology and online services are put in place.

Reliable operation

A solar system is meant to provide power under the open sky and in all weather conditions. A solar panel inverter offers a reliable operation by dissipating heat in a consistent manner.

There are two types of inverters used for solar power installation today; string inverters and microinverters. Note that both inverters will convert direct current to alternating current but they are different in their own way. First things first, what is the real difference between string inverters and microinverters, and what advantages and disadvantages do they have over each other?

String Inverters

Also known as standard or central inverters, string inverters are by far the most commonly deployed option globally and comprise the vast majority of the world’s inverter market. A string inverter converts electricity from multiple solar panels or a string of panels.

Advantages

  • They have low power consumption, low impact of failure and convenient replacement and maintenance.
  • It is a trusted technology because it has been around for decades, and therefore it has become more reliable since it is well understood by electricians.
  • They are currently cheaper than micro inverters. You only need one string inverter per installation, while for microinverters you would require one inverter per panel.
  • Due to their small volume and lightweight, they are easy to handle and install. They do not need specialized tools and equipment or a special distribution room.

Disadvantages

  • If the inverter breaks down, the whole solar system will not operate. This could be a significant loss of electricity production.
  • In case you want to expand in future, you would need to buy an additional inverter as once installed for a certain rating, the rating of the inverter cannot be altered.

Micro inverters

They perform the same basic function as string inverters but are installed underneath each panel on your roof. They convert electricity from each individual panel to the distribution grid.

Advantages

  • This technology allows for individual panel monitoring and they are easier to fix.
  • Allow for full modularity and future expandability without having to buy a new inverter.
  • They enable Maximum Power Point Tracking of each solar panel, making them more reliable than string inverters.

Disadvantages

  • They are more expensive than string inverters.
  • You will end up having as many inverters on your roof as you have solar panels.