String vs Micro Inverters – What is the Difference?
AC and DC Electricity
Before we get into the difference between String and Micro-Inverters, let us go into why you need an inverter in the first place.
There are two types of electricity AC (Alternating Current) and DC (Direct Current). AC allows electricity to travel extended distances and thus is best for long run transmission of electricity. This is the reason why our homes and businesses run off of AC electricity. On the other side of the scale cars/vehicles run on DC electricity. DC does well for short distances and
Solar electrical systems produce DC electricity. To use this electricity in our homes and businesses it must be converted to AC. An inverter takes DC electricity and converts it to AC. The converted electricity is then used in the home/business.
Solar has traditionally utilized string inverters to convert the DC electricity from solar panels. String inverters, sometimes called a central inverter, are usually placed near the home/business-main electrical panel (fuse box) or electrical meter. Depending on the size of the solar install there will be one to three string inverters. Modern String Inverters are the size of a larger electrical box.
DC electrical wires, called strings, are run from each solar panel on the roof to the string inverter. The String Inverter then converts the DC electricity into AC, and it is feed into the main electrical panel or electrical meter. String Inverters are
Micro Inverters fit underneath the solar panels themselves and convert the DC panel electricity to AC on the roof. The AC lines are then fed down to the main electrical panel or electrical meter. Micro Inverters are about the size of the WIFI router. Depending on the design, one micro inverter can handle one to four solar panels.
Replacing an Inverter
As with any electrical part, inverters will eventually need to be replaced. Replacing a string inverter is fairly easy, as it is accessible. Replacing micro inverters requires getting on the roof and removing each solar panel to access and replace the microinverter. Then the solar panels must be remounted on the roof.
Which is Better?
As long as a quality brand with a good warranty is purchased, both types of inverters are great options for solar. The best one will likely depend on the best price at the time you purchase solar.
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