What an Inverter Does for Solar
Last Updated: March 2, 2021
While solar panels get a lot of attention, other elements go into a solar array. An inverter is one of these components. A solar inverter switches the solar power generated by the solar panels to a usable current so you can power your home.
What is a Solar Inverter?
A solar inverter is a piece of equipment that changes direct current (DC) to an alternating current (AC). Changing this current is necessary because solar panels produce DC, and homes use AC.
Although DC is often needed to run appliances, AC runs through the power outlets. Charging cords have rectifiers in them that change AC to DC.
The current in our power outlets uses AC because it’s easier to manipulate. It can be amplified or reduced by a transformer, making utility-scale power easy to transport. Because of the current type that homes and charging cords use, solar-produced electricity can’t power homes without an inverter.
Deep Dive Into Solar Inverters: What Converts DC to AC
DC produces a straight line of current while AC creates a wave. Hence, the names, direct and alternating. To go from DC to AC, the current switches between two contact points at high speed.
The switching current creates a choppy wave known as a Square wave. A transformer then amplifies or reduces this current as needed.
Inductors resist change in the current flow, and capacitors store electrical energy, making the wave’s transition smooth. This process transforms the square wave sent to the home into a sine wave: the same wave of AC the grid generates.
Wiring Inverters: Parallel vs. Series
Inverters change the current type and maximize the power output of the solar array. This value manipulation is possible by adjusting the amperage and voltage of the system. Multiplying these two values together equals the wattage the solar array will produce.
Installers often either wire solar panels in parallel strings or a continuous series. The wiring method used does different things for the system.
Each solar panel in a series adds to the voltage of the system but not the amperage. If one solar panel in a series becomes shaded, it will negatively impact the entire system’s current generation.
Each solar panel on parallel strings increases the amperage but not the voltage, decreasing the impact shaded solar panels have on the rest of the system. The best stringing method depends on the max wattage each configuration can achieve.
What Size Inverter do I Need for Solar?
Not all inverters are the same. Each has a different wattage rating.
Determining the wattage needed for an inverter depends on a couple of factors. These include the size of the solar array, the amount of sun the area gets and the multifaceted factors that determine the array’s efficiency.
These elements determine the end wattage of a solar array. The wattage of the solar array and the inverter then get matched.
Over and undersized inverters will not convert all of the available electricity. It is best if the inverter has as close to a one-to-one ratio to the solar array as possible. You can find this ratio in the inverter’s maximum power point range.
Types of Solar Inverters
The type of solar inverter used can have a drastic impact on the efficiency of the entire system. Although many inverter brands exist, they all fit into two groups. These groups include string inverters and micro-inverters.
Everyone has different priorities when they purchase solar. These priorities play well into the differences between these inverter types.
String Inverter vs Central Inverter
Installers often install string inverters near the meter or inside the home. These systems require large amounts of unshaded space to work at full capacity.
While central inverters, like the Hi-Q inverter, sound complex and different, they’re a large string inverter. Utility and commercial projects often use this inverter type.
Microinverters have scaled-down components to meet the needs of one solar panel. One microinverter goes on the back of each solar panel in an array. These inverters increase the performance of a partially shaded system and the flexibility of the system’s design.
Power Optimizers and Sting Inverters
DC power optimizers are a string inverter enhancer. Like the micro inverter, this device solves string inverter shading problems.
Power optimizers increase the DC of the solar panel before converting it into AC at the inverter. It monitors each solar panel and maximizes production.
Go Solar Group currently uses the SolarEdge optimized string inverter. To learn more about what a solar system with this inverter can save you, request a solar quote for your home.