Inverters do the important task of converting your solar power into usable alternating current. Here’s how to choose the right one for your home.
A solar inverter is a component that uses the direct current from your panels to convert the alternating current that is used to power your home.
Although the inverter is typically not as visible as solar panels, it’s still important. There are various considerations to take into account when choosing one.
What does a solar inverter do, exactly?
Direct current is the type of electricity that flows in a straight line instead of a winding one. It’s what your solar panels produce and can’t use directly.
It’s the job of a solar inverter to convert the DC power from solar panels into AC power that a home can use.
Types of solar inverters
Aside from converting DC-to-AC, implementing a grid-tie inverter is also an important component of any solar system. This type of inverter controls the flow of electricity from the grid to and from the system.
Your solar panels may be producing more power than your house uses, which means you have to send that electricity into the grid. Or, it could be that your house is partly or entirely powered by solar.
Off-grid inverters are also used for systems that are not connected to the grid.
There are a few types of grid-tie inverters that are available.
String inverters
You can also have solar panels on your roof wired together using strings that are connected to an inverter. This type of system is the least expensive option.
Lower cost does come with some drawbacks, however.
A power drop in one panel can cause a string inverter to malfunction. It could be caused by shadows from a nearby building or a tree.
When used with string inverters, solar arrays tend to experience reduced power collection due to their varying shading characteristics.
Shadows aren’t the only problem. A faulty panel can cause a power drop that has a similar effect.
Some string inverters have a feature called a maximum power point tracker, which can increase the output of a string of panels. This feature helps maximize the electricity that’s available from the panels.
Some inverters have more than one MPPT, each of which can optimize the power output of one string.
If your home solar array has multiple MPPT units, your inverter can handle each one individually. Two or more units will allow you to wire multiple strings together.
One other issue with string inverters is that they can’t tell you which panels are responsible for the system’s overall performance. This means that even if you lose power, it won’t tell you if it was a single issue or a series of issues.
String inverters typically have a shorter lifespan than more advanced ones. In most cases, solar panels can last for around 25 years.
String inverters have a limit on the number of panels they can charge. For instance, if you decide to buy a new electric car, they will only allow you to charge it with a limited amount of panels.
One of the main reasons why people choose string inverters is due to the cost. Although it’s possible to get a better system with fewer panels, it’s also more expensive than a microinverter.
It’s also cheaper to service a string inverter than a microinverter. Having someone climb on the roof to install one is also less expensive.
If your roof has no shade, a string inverter can provide up to as much electricity as a more advanced system. However, if you have a little shading, the added electricity may not be worth the higher price.
Finally, some string inverters can do nifty things such as supply emergency power in a blackout, even without a battery.