DC to AC Voltage Conversion: What to Know

Renewable energy systems produce direct current (DC) power, but alternating current (AC) is the standard for electricity in homes and businesses and the appliances, devices, and systems they rely on. Because of this disconnect, converting DC into AC has proved critical as more individuals, households, industries, and regions work toward a more sustainable energy future.

Below, learn about the conversion process from DC to AC voltage and how inverters can simplify it.

What Is DC Power?

DC power refers to direct current electricity flowing consistently in only one direction, with electrons moving from the negative pole to the positive pole. If you looked at this waveform on a graph, you’d see a straight line. 

DC provides a steady flow of electricity, which is excellent for sensitive electronics and batteries. Solar panels also produce DC electricity and then send it to a battery for storage, where it may need to be converted into AC power to be used.

What Is AC Power?

AC power is an alternating current, which changes its directional flow periodically at a frequency of 60Hz. This means the current changes its direction from forward to back 60 times per second. On a graph, AC power would be represented by a sine wave.

AC power can be transported over long distances with minimal power loss. It’s produced by coal, gas, hydroelectric, and nuclear power plants. AC is an international standard for all homes, businesses, and electric machines.

What are the Differences Between DC and AC Power?

AC and DC currents provide electricity but vary in their energy flow, storage, distance capabilities, safety, and use cases.

Energy Flow: The most significant difference is right in their names. Direct current energy flows directly forward while alternating current energy alternates its flow in both directions. 

Storage: DC electricity is much easier to store than AC power, and backup batteries typically store DC power. It may need to be converted into alternating current before it can be used.

Distance: AC power can travel long distances safely, while DC is best used when transferred short distances. Alternating current experiences minimal energy loss over these distances, which avoids overheating the wire and reduces the cost of energy transmission.

Safety: Both electric currents can be dangerous. However, AC is riskier and is more likely to cause heart fibrillation or even death.

Uses: AC electricity is used for power distribution, home and office, industrial applications, and various transportation systems. DC electricity is used for electric transportation (such as EVs), telecommunications systems, renewable energy systems, and modern electronics.

How Is DC Converted to AC?

An inverter, including those found in inverter generators, can easily convert DC to AC power, which is the electric current for all appliances. To change a current that only flows in one direction to a current that flows bi-directionally, a component called an H-Bridge within the inverter changes the polarity. Powered by transistors, the H-bridge constantly alters the current’s flow several times a second to achieve the desired alternating current output.

You can experience this happening in real-time anytime you use EcoFlow Portable Power Stations. For example, your EcoFlow DELTA Series Portable Power Stations can store direct current energy in their robust battery storage. Then, once you’re ready to use the power, you can plug it into one of the device’s AC outlets, and it will convert the DC into usable AC energy.

Connect your PPS to solar panels to create EcoFlow Solar Generators, which also convert DC to AC. Whether using the EcoFlow DELTA Pro Ultra, EcoFlow DELTA Pro 3, or another model paired with its appropriate panels, the panels will generate direct current electricity and send it to the battery component for storage. Before using your stored renewable energy, the internal inverter will change it into AC power.

Why Is DC to AC Conversion Necessary? 

Conversion (different from inversion) is important because we exist in a world where both alternating current and direct current electricity are vital. Most renewable energy systems, including solar, also generate DC power, so we must convert it into AC to use this clean, eco-friendly energy. DC to AC conversion is also necessary for batteries like electric cars, so we can’t escape it. 

DC to AC Power Conversion Formula

The formula for converting direct current to alternating current requires the number of DC watts and the inverter’s efficiency rate. Using these two figures, we can then plug them into this calculation:

(DC watts x inverter efficiency rate) / 100 = AC Watts

If the inverter’s efficiency is 90% and the watts are 330, we’d have this formula:

(330 x 90) / 100 = 297 AC watts

There’s another formula you can use to convert DC to AC amps.

For 12V DC systems, you’ll need about 10 amps of DC input per 100W output to run an AC load. If you need to run a 1500-watt electric heater, for example, you’d use this formula:

(1500 x 10 = 15,000) / 100 = 150 amps

For 24V systems, you’ll need about five amps of DC input per 100W power output to run an AC load. If you need to run the same heater, this would be your formula:

(1500 x 5 = 7500) / 100 = 75 amps

As you can see, voltage matters because you’d need half the amps for a 24 V inverter and half the amps to run the same load as a 12 V inverter.

How to Convert DC to AC at Home?

Converting DC to AC power at home requires an inverter, which you may have built into your inverter generator or need to provide one. There are two key steps to the conversion process:

1. Convert DC to AC

The inverter’s challenge is to change a straight signal into an alternating waveform while minimizing power loss. Usually, this can be triggered with a simple switch that turns the direct current power on and off to create an alternating signal. However, at this point, the current is still only flowing in one direction, and we’re not yet getting an alternating current signal.

Next, the inverter uses its transistors (usually a 4-way switching bridge) to reroute the current and cause it to alternate at a set frequency. Now, we finally have an alternating current. 

To transform it into a wave, the inverter uses electronic components and diodes to smooth the signal until it becomes that sine wave we’re after. Pure sine inverters can do this, while modified sine inverters can only approximate the sine wave.

2. Step-Up the Voltage

The energy has now successfully been converted into AC, but it won’t be usable until it’s at the correct voltage that our appliances require. For that, the built-in transformer can increase the voltage using electromagnetic induction. The transformers have an iron core with two copper wire coils. 

They pass the current from one coil to the other, and the density of the wiring determines the output voltage. When the secondary coil is wired more densely than the primary one, the result is an increased voltage.

Now you’re ready to use your AC power. While this might sound complicated, the process is often simplified with built-in inverters within your solar generator.

When Do You Need a DC to AC Inverter?

These inverters are used constantly. You use a micro-inverter anytime you charge a phone or laptop using a wall plug. You can also use a solar inverter if you have a solar power system at home that you use to run appliances. 

What Appliances Can You Run with DC Power?

DC appliances can help you save money and provide better efficiency. Some appliances that require direct current power include:

• Refrigerators
• Freezers
• LED TVs
• Electric fans
• Electric pumps
• Crock-Pot Cookers

Frequently Asked Questions

Final Thoughts

While it might seem simpler if all appliances, devices, and systems used either DC or AC power, the reality is that we need both. Certain systems, like solar energy systems, are designed to create DC power, so we must have conversion capabilities to ensure we can use this clean energy. 

Luckily, inverters and inverter generators like EcoFlow’s Solar Generators make it easy to turn direct current into alternating current for your home.