Solar Panel Amps Calculator: What’s a Panels Current? -
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Solar Panel Amps Calculator

Short on Time? Here’s The Article Summary

The article discusses understanding solar panel current and calculating solar panel amps, essential for assessing a solar setup's performance. It explains that a solar panel's electricity generation depends on its size, sunlight intensity, and the circuit it's connected to, with larger panels not always producing higher current.

To calculate amps, a digital multimeter is used to measure the current produced by the panel, providing safety checks. Alternatively, manual calculations involve dividing the panel's power rating by its maximum power voltage, following Ohm's Law. The article also explains how current flow works in solar panels, converting sunlight into electricity. Reading solar panel specifications, typically tested under Standard Test Conditions, is essential. It's noted that while specs indicate optimal performance, real-world conditions may vary. The article concludes with information on portable solar panels and their advantages for travel and nomadic lifestyles.


To familiarise yourself with the ability of your solar setup, have a look at our solar panel amps calculator. Knowing this makes it easy to do further calculations or simply to understand the power supplied by your solar setup to your home.

A solar panel generates electricity when placed in the sun. The amount of electricity the panel produces depends on the size of the panel, the intensity of the sunlight, and the circuit it’s connected to. 

Generally speaking, a larger panel generates more electricity than a smaller one, but this doesn’t necessarily mean it generates a higher current. To explain this properly, we’ve looked into the relationship between watts and amps and how the quality of your solar panel affects both.

Let’s learn more about electrical equations, solar panels, and how to measure the amps of your solar panel.

Understanding Solar Panel Current

The best way to calculate the amps produced by a solar panel is by using a digital multimeter.

 solar panel amp calculator

Begin by connecting the positive and negative probes of the multimeter to the positive and negative terminals of the solar panel. 

Make sure that the multimeter is set to measure DC current in amperes (A). You need to do this since the panels produce direct current (DC) which is then sent to an inverter where it’s converted for AC that’s used in our homes. 

Provided everything is wired properly, the multimeter should then display the amps produced by the panel. This is also a good way to check that everything is safe and correct. If you don’t get a reading, or get a reading that’s far too high, you know that something’s wrong.

If the panel is connected to a circuit, the current is affected by the power rating of the solar panel, the amount of sunlight that is falling on the panel, and the characteristics of the circuit. 

This means there’s a difference in the current produced by your panel based on factors like resistance within the circuit. 

What happens if you don’t own or have access to a digital multimeter? This is where manual math comes in. It sounds daunting, but we’ve broken the steps down for you below. It’s easy to follow.

Because amps, volts, and watts are inextricably linked, simply knowing one variable is generally enough to work out the other. If you need to calculate the kWh produced by your solar panels, figuring out the amps is a good place to start.

Calculating Solar Panel Amps

To calculate the current when your solar panel is generating its maximum power, you need to divide the maximum rated power of the panel in watts by the maximum power voltage (Vmp) which is also in volts. 

solar panel watts to amps calculator

You can find the wattage of your panel on the back of it, or in the installation manual.

In short, the current produced by a solar panel can be calculated by dividing the power rating (in watts) by the maximum power voltage (Vmp). 

As an example, if the solar panel is rated at 300 watts and the Vmp is given as 12 Volts, the calculation will look like this:

I = P / V 

Read the above as current equals power divided by voltage. Current is represented by an I according to Ohm’s Law, and power refers to the wattage of the system. We’ll explain this in more detail below. 

Back to the equation. 

I = 300 / 12

  = 25 A

It’s as simple as that, so don’t stress if you don’t have a multimeter.

Ohm’s Law

Now that you’ve seen the equation, let’s learn a bit about why it’s done that way. The equation is set according to Ohm’s Law, which governs many electrical sums. 

Georg Simon Ohm proposed Ohm's law in 1827 and experimentally verified it the same year. The law states that the current passing through a conductor is directly proportional to the voltage applied across it. 

solar amp calculator

This means that if the voltage is doubled, the current passing through the conductor also doubles. This law is fundamental to the study of electricity and electronics and is used in the design of circuits.

The Calculation

The mathematical relationship between current and voltage is represented as V = IR.

Read in English: voltage is equal to current multiplied by resistance. We can rearrange this formula to solve for a host of variables in terms of electricity, and that’s why Ohm’s Law helps us solve for current.

How Do I Read the Specs of My Solar Panels?

Reading the specs of your solar panels can get a little confusing. They’re always available either on a sticker on the back of the panel or in the manual. 

However, there are so many specs listed that as a newbie, you might not even know what you’re reading. That’s okay, we’re here to help. It’s important to be able to read the specs of your panel correctly before you do any calculations.

It’s also important to understand that the values given on your solar panel have been tested under Standard Test Conditions. We’ve explained this below.

Standard Test Conditions include a cell temperature of 77 °F and a light intensity of 1,000 watts per square meter. This is equivalent to the light intensity of the sun at noon.

It also includes an atmospheric density of 1.5. This is what your panel experiences when the sun's angle is directly above the panel. It's important to note that voltage and current change depending on various factors, such as temperature and light intensity.

solar panel current calculator

Don’t worry about gaining a deep understanding of the Standard Test Conditions. All you need to understand is what they mean in your context. Basically, the values represented on the back of your solar panel refer to how the panel performs in optimum settings, or when the sun is at its highest and brightest.

This means your panel might not always perform as well. They are, however, a good indication of the performance of your panel. So use these values to do your electrical equations, and just keep in mind that it’s possible for your answers to be slightly over or under.

How Does Current Flow in a Solar Panel?

We’ve got some good news if you’re interested in learning how a solar panel turns solar power into electricity. Below, we’ve explained the basic steps for you. 

When sunlight hits the solar panels, it creates an electric field. This electric field flows through a conductive wire and is then sent to an inverter. 

Have a look at our solar panel inverter size calculator for more help in that department.

This inverter changes the electric field from DC (direct current) to AC (alternating current) electricity, which is the type of electricity used to power homes and buildings. 

From here, the AC electricity is sent to a breaker box, which distributes the electricity throughout your home, or to the appliances plugged into your inverter if you have a smaller setup. 

solar panel output calculator

Any electricity not needed is then sent to the utility meter, and then to the utility electrical grid. This flow of electricity causes the meter to run backward and credits your property for the excess electricity generated. This might differ by state.

What’s Current for?

Current describes how quickly electricity flows through the circuit, not necessarily how much electricity is flowing. So, if an oven uses 900 watts, it doesn’t matter how much current your solar panels produce, right?

Yes and no. The answer is a little more complex.

In order to get enough power at once, appliances have a minimum current requirement. What the value is varies depending on how power-intensive the appliance is. Thankfully, your home fusebox has transformers that modulate the current flowing through your home, making sure that there isn’t too much or too little current at once.

Current that’s too low means appliances simply won’t work. Too high and they could burn out, leading to damage or worse, an electrical fire.

Your solar panels will go through a similar inverter before you can connect them to any appliances, so the amps they produce don’t matter as much for that.

However, one place where the amps of your solar panels do have an effect is figuring out the charge time for your solar panels

To make up for the fact that solar panels don’t produce electricity at night, you need to connect batteries to your system to provide you with power throughout the day. The higher the current of your panels, the faster these batteries charge.

I’m Looking for Solar Panels

We have a range of 200 W portable solar panels and products for you to have a look at. These are best for use in an RV or an a camping trip. If you’re in the market for something larger, like something that can keep the appliances in your home running, we’ve got you covered there too.

solar panel electricity calculator

Shop Solar Kits has one of the largest selections of high-quality solar products available. All our goods are quality-assured and come from reliable suppliers that are setting trends and breaking records in the world of sustainable energy.

Portable Solar Panels

Just because you’ve invested in solar panels doesn’t mean you have to stay put. Our portable solar panels are an excellent choice for the digital nomads and vanlifers among you.

The difference between these panels and regular ones is that they can fold, so they’re easy to transport from place to place. They harness the same amount of sun and are just as powerful as regular panels.

They typically cost a bit more than regular panels, but as we said, they come with the added advantage of being portable. Because they have the same power as a regular panel, you can use them to power all the appliances you need on your road trip or camping trip.

They provide convenience, ease of transport, and the ability to take them from place to place. 

However, they don’t have the same longevity as rigid solar panels. To get the most out of your folding solar panel, you should take care to store it in a cool, dry area and use it sparingly. 

solar panel sizing calculator

Additionally, if you are using it to power electronics, be sure to use the correct voltage and amperage to avoid damage to the panel. With proper care and maintenance, your folding solar panel can help power your life for years to come.


Once you know the current that’s being produced by your solar panels, you can go on to work out a great many important things about your system. Current (amps) is a fundamental variable of any electrical circuit.

Have a look at our solar panel cost calculator to learn more about how your panel can pay itself off in no time, and eventually generate free electricity for you and your family. 

If you’re set on having permanent solar panels installed on your home’s roof, have a look at our solar panel roof load calculator. This will give you an idea of how many panels you can install on your roof.

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Article by

Cody Oehm

Cody is the Head of Marketing at Shop Solar, and joined the company in spring of 2022. 

He has an entrepreneurial background and has been in the ecommerce industry since 2015. With 4 businesses under his belt and a drive to make a bigger impact, he decided to team up with Shop Solar on their mission to make solar simple and affordable. You can browse best seller's here.

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