What is a Solar Panel Inverter?
A solar panel inverter is a device that converts the Direct Current (DC) generated by solar panels to Alternating Current (AC), which is the type of electricity used by household appliances and electronic devices. The inverter also converts the voltage generated by the solar panel from 12 volts DC, to 110 or 220 volts AC, in U.S. applications.
Types of Solar Inverters
- Off Grid Inverter
This type of inverter is used with an off-grid solar power system. Also called a stand alone system, the off-grid system is not connected to the electrical power grid. Off-grid systems connect the solar panels to a bank of DC storage batteries, with the inverter placed in-line between the batteries and the breaker box that distributes power to your home. The inverter draws DC current from the batteries as needed, converting it to usable AC current.
- Grid Tie Inverter
A grid tie inverter connects directly to the solar panels, converting the DC electricity to AC, then sending it directly to the breaker box for household consumption. Grid tie inverters work in tandem with the electric grid so can be configured for net-metering, allowing excess electricity to be sold to the utility company.
- On/Off Grid Inverter
Used in grid-tied applications, but offer the benefit of electricity storage in a battery bank. Use of an on/off grid inverter will provide power during a utility grid blackout.
- Mini Inverter
Mini, or micro inverters are small inverters that are fitted to each individual solar panel in the system. This allows each panel to operate at its peak, regardless of the performance of other panels in the system, also allowing for multiple types of solar panels within the system.
How Long Do Solar Photovoltaic (PV) Inverters Last?
The average lifespan for a PV inverter is between 15 and 20 years. Most manufacturers offer a 10 to 15 year warranty.
How Much Does A Solar Panel Inverter Cost?
The cost of the inverter depends on the type selected, what type of solar panels you select, and the amount of wattage and voltage needed for your system. Using both grid tie and off grid inverters with a 120 volt AC/4000 watt load as an example, prices typically range between $1,600 and $2,800. Mini inverters that have an average rating of between 190 and 220 watts typically cost between $165 and $200 each. Keep in mind that prices can vary widely, depending on where you buy them and the brand selected for the system.
How The Solar Inverter Is Connected to the Grid
The PV system is connected to the electrical grid through a bi-directional interface connected through the breaker box. The inverter converts the DC power to AC power of compatible quality to the utility grid, feeding unused electricity into the grid.
How To Choose A Solar Inverter
Choosing the right solar inverter is determined by what its intended use is. The main things to consider include: whether the system will be on grid or off grid, what type of solar panels will be used, and the total amount of wattage needed.
How To Size Solar Inverters
To determine the size inverter needed, add up the amount of watts used by each appliance in the house by how many hours per day it is used, add them together and this will give the approximate wattage needed.
How To Wire Solar Panels To The Inverter
Start by connecting the input terminals to the charge controller. The next step is to connect the charge controller to the inverter. Make sure to use the correct size wire to ensure optimum performance of the system.
What Are The Best Inverters For Solar Panels
Xantrex offers mobile power inverters that come in a variety of sizes and power ranges, providing power when and where you need it. Their ProSine, ProWatt, Pro and XPower series inverters can handle nearly all mobile power needs.
Sunny Boy – SMA America is an industry leader in small and mid-range systems. Innovative technology in both transformer and transformerless type inverters provide high efficiency performance in all TL-US models. Wattage ratings range from 3,000 to 10,000.
Fronius USA offers two lines of grid-connected inverters. The IG line is designed for smaller systems, up to 2,500 watts, and offers compatibility with all traditional PV panels. The CL product line is designed for larger systems, up to 60 kW, and features a modular system design.
Enphase offers an innovative line of microinverters ranging from 190 to 215 watt ratings. The M190, M210 and M215 inverters all come with built-in connector cables for easy installation and offer up to 95.5% efficiency.
Aurora offers several types of inverters to meet a variety of needs. The Aurora product line includes the Micro 300 watt mini inverter, the Optimizer DC-to-DC technology line, the Uno single-phase inverter for residential and small commercial applications, and the Trio three-phase commercial inverter.
Advanced Energy (AE) provides both transformer-based and transformerless string inverters for both commercial and residential applications rated for loads ranging from 2 to 7 kW. AE’s PVP line of inverters are designed for easy installation and outstanding reliability.
GE offers their new Brilliance line of commercial inverters in models ranging from 700kW to 1 MW to meet the most demanding commercial applications.
BP Solar Grid Connect inverters are user friendly and reliable. The GC product line is offered in both residential and commercial models.
Sharp offers an innovative approach with the Sharp JH-3500U inverter. This 3.5 kW inverter will accept three input strings, allowing a variety of PV module configurations.
Apollo Solar features high efficiency off grid solutions with their TrueSineWave Inverter line in 3200 and 4000 watt models designed for residential use.