Short on Time? Here’s The Article Summary

The article provides a simple solar DC-to-AC conversion calculator and aims to simplify solar power for beginners. It explains the difference between DC and AC power, highlighting the need for conversion in solar power systems. The article introduces two types of solar charge controllers, PWM and MPPT, and discusses their functions. It also provides a formula for converting DC to AC power, considering the efficiency rate of the inverter.

An example calculation is provided for better understanding. The article explains power loss factors in a solar system, such as conversion loss and internal temperature effects on the inverter. It concludes by emphasizing the importance of understanding these calculations to ensure the solar system operates optimally.

Introduction

You’ve come to the right place if you’re looking for a simple solar DC-to-AC conversion calculator. 

We love that so many people and businesses are looking to take advantage of all the natural, sustainable energy we have available to us. 

However, we understand that it can be a little daunting to begin with. Online information can seem a little all over the place, and we’re here to help. Our mission is to make solar simple and accessible. 

On that note, let’s dive straight in.

DC vs AC: What’s The Difference?

If you’re a beginner, you might wonder why you need to know this information in the first place. Simply put, solar panels produce a type of power called DC, or direct current. This is what’s stored in their batteries.

The type of power used by our appliances, however, is AC, or alternating current. You need to do some conversion maths to know how much power you have available in your solar power system that you can actually use.

The tool that does the conversion for us is the inverter.  

Ultimately, you can’t see the voltage available in your DC battery and assume that’s the amount of AC volts you’ll have available to power your home or business. You also need to factor in other things, such as resistance. 

This could cause you to lose some power in the process of inverting, which is when DC power is converted to AC power by your inverter. You could also lose some power due to resistance in your home wiring. 

Conversion Formula: DC to AC

The important question: so how do we do this? It’s pretty simple. There are a few steps, but they’re not difficult to understand.

First, you need to know that most inverters run at about 90% efficiency. This means there’s 10% resistance. To double-check the values of your system, you can check the efficiency rate listed under the specs of the particular inverter you have. This is usually somewhere on the bottom of the unit.

You need to take this resistance into account when doing the DC to AC conversion. 

Note that when we do this calculation, we’re making the assumption that there’s no resistance in your appliance wiring. There normally is, but it tends to be minimal enough to not affect the equation. 

If, however, you’re still worried about it, check out our voltage drop calculator so you can figure out how much it’s affecting your system.

The formulas you’ll use are the following:

AC Watts = (DC Watts * inverter efficiency rate) / 100

AC Amps = (DC Amps * inverter efficiency rate) / 100

You can choose which formula you want to use. It all depends on whether you want to know the Wattage or the Voltage provided by your solar power system.

How Does the Calculation Work?

As we said, it’s pretty simple. You just plug in the values you have, and you have your answer. 

Useful Example

We’ll take you through an example to illustrate how to use the above formulas, based on these portable solar panels for RVs.

Say, for example, you have 200 W portable solar panels. You might have more powerful ones if they’re installed on your roof, but we’ll use 200 W for this example. 

To work out the AC Wattage, you multiply 200 by 90% (the inverter efficiency rate). If your inverter has a different efficiency, you’d replace 90% with the actual efficiency rate of your inverter.

Your equation would look like this:

AC Watts = (200 * 90) / 100

The answer would be 180 AC Watts. This is how much usable electricity you have to use for appliances.

These numbers can be useful when you’re trying to figure out if it’s worth it to make the move to solar, or supplement your current usage with solar power. Use our solar payback calculator to work out how long it’ll take for your solar system to pay for itself, so you can start saving on your energy bill.

To make the most of your solar panels, you want to angle them correctly. As part of our mission to make solar simple, we've also created a solar panel angle calculator that you can use. 

If you’re using a portable solar panel, you’ll also want to know which time of day is best to put it in the sunlight. We put together some great information on the sun’s peak hours for you.

Power Loss Explained

There are a few factors that can lead to power loss. These can be frustrating, especially when your solar system is your primary source of power.

When your power is converted from DC to AC current, you lose roughly 5–15% of the power your panels made. That makes this conversion the first reason you’ll experience power loss.

You could also lose power because of internal temperature. 

For an inverter to work optimally, you need to avoid a process called derating. When you use the inverter at its maximum capacity for an extended period, it deteriorates. This means it stores less and less power the more you use it.

This is because the higher the temperature of the wires in the circuit, the higher the resistance is. This decreases the current your system is capable of.

Derating happens because the inverter has to work harder to cool itself down, using more power than necessary. It’s best to store your inverter in a shady or cool area so that it never rises too far above room temperature. Try to keep your inverter cooler than 120 degrees.

You’ll experience power loss when you use the incorrect wire as well. The higher the voltage of the system, the bigger the wire you’ll need. 

Now you know everything you need to know to do the calculation, and what other factors you might need to take into account if there is any variation in your solar power system. 

Conclusion

We totally understand why these kinds of conversions look scary at first glance. There’s often a lot of confusing terminology bandied about that can make it impenetrable for people who aren’t already experts.

By taking the time to slowly walk you through the process, we’re confident that you can now do all the calculations you need to rest easy that your system is working at its optimum level.

If there are more topics that you’re still unsure about, check out our blog post. We’ve got plenty of other resources to help you out. Whether you’re looking for a solar calculator for your RV or you want to calculate how much solar you need, we’ve got you covered.

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