he solar market is on the increase. In the past, PV panels weren't efficient enough to make a difference for residential users, but things have changed now. As technologies develop, households continue discovering new options to achieve their goals of saving money and reducing environmental impact.
The cost of a home solar installation has halved in a decade, which speeded up the adoption of solar power. The energy generated by solar panels can be used for a variety of domestic purposes like generating electricity, heating, lighting, etc.
However, in order to benefit from going solar, a homeowner must choose a solar power system as carefully as possible. The first thing that comes to mind is finding the most suitable panels, but other components must be chosen with no less thoroughness. A solar energy inverter is one of them. In fact, the inverter is sometimes referred to as the brain behind a solar power system.
In this article, we will discover what a solar energy inverter actually is and how it works. We’ll also go through the different types of solar inverters available on the market.
What are solar inverters & how do they work in a solar system?
When a solar cell absorbs sunlight, its electrons start moving, creating a flow called electric current. This current is then captured by wires and transmitter further.
At this stage, solar electricity still cannot power your home. The thing is, solar panels produce direct current (DC), which means the electrons only flow in one direction. But most household appliances need an alternating current (AC), meaning electrons periodically change their magnitude and direction.
What an inverter does is convert DC voltage to AC, enabling a solar installation to power your house. The DC current produced by solar panels looks not like a wave, but rather like a straight line. The inverter grabs DC power and runs it through a sort of transformer to create a sine wave (AC voltage.)
Solar inverter types for your PV system: how do they differ?
String solar inverters
The most common solution for small-scale residential solar systems is a string inverter. In a system with this type of inverter, PV panels are arranged into groups and linked together with a string. Several strings are connected to the inverter, which receives electricity flowing from solar panels and converts DC into AC so that it can power your home.
String inverters are usually the easiest to maintain, as they are normally located in the basement or garage and easy to access. They are the most affordable of all since you only need a single inverter to convert all the power your solar panels produce into appliance-friendly electricity. Besides, string inverters are usually less prone to breakage due to their simpler structure.
But on the flip side, a dip in performance of one panel decreases the efficiency of all other panels in a string. That is why string inverters aren’t the best choice for the areas with regular shading. On top of that, they might not work with more nuanced systems where solar panels can’t be arranged into strings.
Another option is microinverters, where each solar panel has its individual inverter installed next to it. Unlike central string inverters, which collect electricity from panels via strings, microinverters convert DC to AC straight away on the rooftop.
These inverters are perfect for more complex solar system designs and more shaded locations. They smooth out the effect of shading, allow you to track how each panel performs, and make sure each of them is running properly. One more advantage - it is much easier to add solar panels to an existing installation. All you have to do is purchase an extra microinverter for each new panel added.
However, this inverter type has its drawbacks as well, and high cost is a primary one. Besides, microinverters are more difficult to maintain since they are installed on the roof and hence less accessible.
Solar power optimizers
This solution is a middle ground between string inverters and microinverters. Power optimizers are attached to each panel in an array just like microinverters, but the electric current is sent down to one main inverter like in string inverters. Power optimizers do not convert DC to AC like other inverter types, but condition the DC voltage to increase conversion rate.
Power optimizer systems can be a great solution if you have a complicated roof or regular shading, helping to improve the performance of your solar panel. If you can’t afford microinverters but still would like to maximize the output, this might be the way to go.
Hybrid solar inverters
A hybrid inverter has features of both solar and battery inverters. It can convert DC to AC electricity for your home use as well as collect AC from the grid and convert it to DC power, which can be used for charging solar batteries. If paired with batteries, hybrid inverters enable you to keep your lights on with backup power in times of grid failure.
Is a solar inverter expensive?
The cost is largely dependent on the inverter type and capacity. On average, inverters account for about 6% of overall installation costs.
String inverters for a mid-sized solar system can be purchased for $1000-$1500. The price of microinverters averages at $150-$215 per inverter. It is typically $1,000 or more above the cost of a string inverter needed for a system of the same size.
Power optimizer for one panel ranges in cost from $200 to $800, but remember you’ll need to buy a central inverter as well.
Does it last long?
String inverters last an average of 10-15 years. However, if an inverter is well-maintained and placed in a shady and properly ventilated spot, its lifespan can be as much as 20 years.
Both microinverters and power optimizers usually offer a 25-year warranty.
Wrap-up: solar inverter is crucial for your solar PV system
As you can see, the efficiency of solar power generation is not about panels only. It is a complex system, where each component has to perform at its best to deliver the highest output possible.
Whether it’s a large solar PV plant or a tiny solar powered house, the inverter plays a crucial role in power generation. It converts direct current into alternating current making the power produced by panels suitable for home use. Solar energy inverter can also optimize your PV system output, help monitor how much electricity you consume, and ensure backup power supply.
They all differ in size, functionality, and price. There are over 60 inverter manufacturers in the US, and you should carefully consider the options available in the market to find the one that suits your purposes and budget.