How To Size A Solar Inverter

A solar inverter is a kind of inverter that is generated by electricity that transfers the exact electricity output of the solar panel to alternative electricity that could be used as a grid or off-grid electrical medium.

It sounds very complex but is rather very useful. This article is going feature on how you can size a solar inverter.

Sizing the solar inverter is actually a very crucial part of a solar set up no matter how big or small it is in size. Since it is the initial part the further performance will be depending on this.

The solar inverter should be at least of size, that would be able to handle the strain of generating and delivering the DC current to the inverter and convert it into AC power.

Solar Inverter

Understanding the DC to AC Ratio:

The DC to AC ratio is the ratio between the AC power of the inverters and the DC output power of the Solar panel.

The purpose of this DC to AC ratio is to find the optimal balance between the cost and the performance of your solar system.

Most of the solar power systems are designed with a higher DC to AC ratio because of the declining prices of the solar panels. It is recommended to have the DC to AC ratio as high as 1.5 for higher than that.

Calculating the DC to AC Ratio:

If your solar array is having an STC wattage of 350W, and the number of modules in the array are 15.

Then the DC power of your solar array will be calculated by 15*350W which is equal to 5 250 W.

And if you are using an inverter having an AC power of 4200 watts. Then the DC to AC ratio of your solar system will be calculated as:

5250/4200= 1.25W

Pros and Cons of large DC to AC Ratio:

There are many economic benefits of the large digital AC ratio. it is because the production of the Solar array is below the rating of the inverter.

Keeping in mind the Solar market trend of the reduced cost of solar panels, if you design a system with a high DC to AC ratio then you will generate bottom-line solar energy for a lower cost.

However, there is a limit to this DC to AC ratio. If your DC to AC ratio is high then it will cause inverter clipping.

Inverter Clipping:

We very better know that the solar panels are used to produce the DC electric energy which is then converted to AC electric energy through a solar inverter.

This electricity is then directly used to power domestic loads or commercial buildings or any other applications. Or it can also be injected into the power grid.

What we are searching for here is the DC to AC ratio which results in the inverter clipping.

The meaning of inverter clipping is to limit the amount of electricity that goes into your household for use from the Solar energy System.

Now let’s get into the details of this thing. Whenever we oversize the solar panels Power capacity or during the peak production hours such as the noontime when the Solar irradiance is above the standard test condition value, it is common that the DC power that is generated from the Solar panel becomes larger than the inverter power rating.

In this situation, the extra DC power that is generated is clipped by the inverter to ensure the working at the rated value. This ultimately results in the loss of energy production.

In simple words, oversizing the power capacity of your solar panel results in the increased production of energy and most of the day times when the sunlight is at its peak.

So whenever you are going to size your solar inverter then you must keep in mind the loss of energy production due to solar inverter clipping and the increase of energy production because of oversizing the Solar array.

You must add another solar inverter to avoid the solar inverter clipping keeping in mind the price and installation cost.

And that is when the sizing of your inverter part comes in.

The first step of knowing how to size an inverter is to know how you would rate it. The first inverters are rated in continuous watts. And then there are surge watts.

A continuous watt is the subtotal watts the inverter can co-operate with. Meaning, whether it would be able to handle the watts or not.

A continuous watt basically helps you find the right side of the inverter. An inverted should be equal to the solar panel or the solar system’s watts rating.

Not too much or less, because if it is not accurate, the efficiency is not going to be satisfactory and the performance will drop.

On the other hand, a surge watt is the total range of power the inverter may be able to tackle for a shorter period of time.

If you want your inverter to be perfect for your entire system, the surge watts rating has to be equal or even so greater than the surge watts capability itself with each application.

Now, let’s go into further details on how you can size your solar inverter.

Size of the Wire and Inverter Presentation:

The total space between the main panel and the battery is a very important factor to look upon because that distance will intrigue the performance of your inverter.

The bigger sized wire will keep on lowering the voltage leading to a dissatisfactory performance. Because longer sized wire make the voltage of the inverter down as the electricity increases simultaneously.

As for the shorter sized wires, lessens the amount of electricity produced and increases the voltage resulting in higher productivity.

Using More Than One Inverters:

It is sometimes used to generate more power. The idea is to get many small-sized inverters and connect them all together so that they function as one whole inverter.

If you do not want to buy a bigger sized inverter this policy may come in handy. Connecting two similar inverters in a parallel manner will also give you the same results.

How Do Inverters Work In Low Sunlight?

If you can accurately align the solar panel with the batteries and the capacity range of the inverter, the grid connection of the solar system will drastically improve.

During the winter, or maybe a cloudy day when the sun is hardly seen and due to that reason the production gets decreased, this policy will come in handy and will end up giving you a satisfactory result.

Another important thing is needed to keep into account that an extra small-sized inverter will be troublesome as well. Because it will not be able to handle the load and will result in overload causing to lose a lot of energy.

These were the basic things that are needed to be considered in order to size your solar inverter or to find the right solar inverter.

All of these facts are important and it is advised that you look into these matters with an expert if you are not that pro of a person when it comes to technical terms.

Because most of its sizing, accuracy and productivity will depend on these terms, so you must choose them wisely.

Robert