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An inverter is not only a good addition to your home but an essential one. To put it simply, you cannot run most appliances on solar power without an inverter.
Solar inverters make it possible to power your home with solar panels. An inverter converts solar energy into alternating current (AC) so appliances can use it.
What is a Solar Inverter?
An inverter is a device that transforms direct current (DC) into alternating current (AC). A solar inverter like the MXMoonfree 5000W is a type of inverter optimized for solar panels.
Inverters also synchronize solar panels to the grid. It also functions as the bridge between your home’s electric distribution system and the solar panels.
Modern solar inverters can also connect and disconnect your solar power system from the grid. This is a useful feature if you have solar batteries like the LiTime 200ah battery installed.
Grid tied solar panels automatically turn off during a power outage. This is necessary to protect those who will fix the power lines.
With a solar inverter, you can disconnect your solar panels from the grid and run it with solar batteries. Solar inverters also provide information about your solar panels’ performance.
Why Your Home Needs Solar Inverters
Solar panels are a great choice if you want to reduce your monthly power bill. Installation costs continue to drop and the panels are becoming more efficient too.
When sunlight hits the cells on a solar panel, it is converted into electricity. But it cannot be used by most appliances and electronics because it is direct current (DC).
Though some electronics run on DC, households depend on alternating current (AC). This is where an inverter becomes necessary as it converts DC into AC.
How Solar Inverters Convert DC to AC
The following is a simplified explanation of how inverters turn DC into AC. I am using solar panels as an example but the conversion process is similar regardless where the current comes from.
Direct current (DC) flows one way. Alternating current (AC) moves back and forth.
Solar inverters use what is called an H-Bridge to change the one-way flow of DC into the back and forth of an AC.
Another way to put it is that inverters quickly turn DC input on and off. This generates alternating pulses which are refined by inductors, which turn into AC.
After the conversion, the inverter transmits the current into the connected appliances and electronic devices. All of this happens rapidly and automatically.
To summarize the key points:
- Sunlight hits the solar panels.
- Solar panels produce direct current (DC).
- DC goes into the inverter which converts it to AC.
- AC is passed onto household appliances plugged into the inverter.
Note that if you have a Tesla solar roof you will need specialized inverters to work with it.
Which is Better, a Solar Inverter or Regular Inverter?
Solar inverters are optimized for use with solar panels. Regular inverters are designed to convert DC to AC from various sources including solar panels, UPS and batteries.
Both inverter types convert DC to AC, but a solar inverter is more efficient. Compared to a regular inverter, solar inverters can do a better job of transforming DC into AC.
If you plan to install solar panels at home, a solar inverter is a must. Without it you won’t be able to get the most out of your solar panels. A lot of home solar panel kits include an inverter to simplify the installation.
What Size Solar Inverter Do I Need?
Your solar inverter has to be the same size as your solar panel system. If you install a 5kw solar panel system, the inverter has to be at least 5 kw too.
I say “at least” because inverters do not have a 100% efficiency rating. You should have some reserve capacity available in case you need more power. If you don’t max out the 5kw monthly, a 5000W inverter is fine.
Calculating inverter size for battery. To find out how many batteries you need for your inverter, use this formula:
Desired inverter runtime x inverter wattage = watt capacity / inverter voltage = needed battery size (in amps)
You have a 5000W inverter and want to run it for 3 hours.
5000W x 3 = 15000W
Now we divide this by the voltage, 12V in this example:
15000W / 12V = 1250 amps
You need a battery bank with a 1250 amp capacity.
Keep in mind that it isn’t a good idea to completely drain solar batteries. Lead acid batteries for instance, have a 50% depth of discharge so you should only use 50% of its capacity.
AGM batteries have a 70-80% capacity and lithium up to 90-95% So while our example shows you need a 1250 amp battery bank, in reality you’ll need more.
What Solar Inverter is Best for Home?
Aside from the capacity, there are many other factors that will determine which solar inverter is best for your home.
Choose the Right Solar Installer
Installing solar panels and inverters in your home is a large undertaking, so you want to make sure you have the best installer for the job.
- Look for installers with a solid track record and work for reputable companies.
- Check how many solar panels the installer has installed on roofs like yours.
- Always go for installers with experience.
A reputable installer will check your roof before any installation. They will tell you what solar panels and inverters are best for your home.
A good installer should be able to answer all your questions. Here are some of the things you should ask:
- Does the installer provide an output guarantee? For how long?
- How long is the warranty?
- Ask how you can evaluate the performance of the solar panels and inverters. In case output drops, you will know what to look for.
Types of Solar Inverters
The solar installer will tell you what solar inverter is compatible with your setup. But it is a good idea to know what options are available.
In this setup, a string of solar panels are connected to one inverter. The inverter transforms direct current into alternating current for each solar panel.
String inverters are the most widely used with solar panels. They are affordable, easy to setup and maintain.
But if one of the solar panels is obstructed or not working properly, the rest of the system is affected. This is because all the solar panels are linked to one inverter.
You can get around this by installing DC power optimizers, so if the production of one solar panel goes down, the rest are not affected. In fact many solar inverters for home are bundled with power optimizers.
With a string inverter, all the solar panels are connected to one device. With microinverters, an inverter is installed on every solar panel.
Because each solar panel has an inverter, the array won’t be affected if one panel has a low output. Microinverters are ideal if your roof cannot provide the best angle for solar panels.
Microinverters make it easy to upgrade and expand. If you want to add more solar panels, it’s a simple process. With a string inverter it is more difficult since the inverter specs are optimized for the current array.
Grid Tied Inverter
A grid tied inverter is connected to a power grid, which allows you to use either solar power or regular electricity. This is the most common configuration used in homes today.
A grid tied inverter gives you the best of both worlds. You can use solar power and if output is low, switch to the grid.
The disadvantage is that grid tied solar panels do not work if the grid shuts down. If you want to use your solar panels during an outage, you have to install a battery bank and a charge controller.
Off Grid Inverter
If you want to completely disconnect from the power grid, use an off grid inverter. Solar batteries are required so you can keep the power on 24/7.
Off grid inverters do not work with utility grids. Installation is more expensive than grid tied inverters as you’ll need several batteries to supply power.
A hybrid inverter combines a battery and solar inverter into one. You can install this device in off grid and grid tied systems.
If you want to use grid tied solar panels during a power outage, install a hybrid inverter. If the grid shuts down, the hybrid inverter will disconnect your solar panels from the grid. You can then use the battery inverter and batteries to power your home.
If you are off the grid, an off grid or hybrid inverter is required. Otherwise you won’t be able to supply your home with power at night. Hybrid inverters are often more expensive than regular solar inverters.
I am an advocate of solar power. Through portablesolarexpert.com I want to share with all of you what I have learned and cotinue to learn about renewable energy.