AC vs. DC: Alternating & Direct Current Differences & Examples⚡

WHAT IS AC AND DC CURRENT? DIFFERENCES EXPLAINED

Electricity powers almost everything we do, including the device you're reading this article on. Being a large part of our lives, electricity is an important aspect, but did you know not all electricity is the same?

Electricity can come in 2 forms, Direct Current (DC) and Alternating Current (AC), which determines the flow direction of the current. But what's the difference?

What is Alternating Current (AC)? AC refers to the dynamic direction where both positive and negatives are switched at intervals where electrons keep switching directions that change the flow of the electrical current - usually seen in home appliances.

What is Direct Current (DC)? DC is when the current is consistently flowing in the one direction, which is the form of power that is mainly seen in battery storage, solar energy, and devices like phones and laptops.

An electrical current is the flow of electric charge, commonly transferred by electrons passing through a conductor like a wire. This is measured in amperes (A) or 'amps'.

WHAT ARE EXAMPLES OF ALTERNATING VS DIRECT CURRENT IN AUSTRALIA?

To better understand what AC and DC is, let's use some real-life examples on what both AC and DC are used for and their differences.

In Australia, AC current (AC) is the standard for home appliances and grid electricity distribution, and is what the NEM's infrastructure is built on. The power distributed from the grid is AC, which the voltage can be stepped up or down using transformers.

Things like the grid, home appliances, outlets, industrial, equipment, and long-distance energy transmission all run on AC power.

DC current (DC) is what powers our batteries and electronic circuits, and is what powers solar energy and electrical transportation like electric vehicles (more on this later). Elements like phones, laptops, solar & battery systems, AA batteries, and EVs run on DC power.

A real-life example on AC vs. DC, could be the way we charge our phones. Back in the day, we used to get a charging brick included in the box which when plugged in, would invert the outlet's AC power to the phone's DC power. The heat occurs due to the efficiency losses that heat over longer charging periods.

WHAT IS THE DIFFERENCE BETWEEN AC & DC USING DIAGRAMS AND EXAMPLES?

The main difference between Alternating current and Direct current is how the electrical current flows. AC is constantly switching from positive to negative, whilst DC remains steady in one direction. Below are some example diagrams on how direct and alternating current works.

HOW DOES AC AND DC WORK IN SOLAR SYSTEMS?

Using solar and battery systems as an example for AC and DC, the sun shines and generates DC power which is sent to the inverter to be converted to AC for general household usage and grid export.

Depending on if a battery is AC or DC-coupled, the battery may be responsible for its own power conversion or may rely on the hybrid inverter to convert the stored power.

AC and DC is an important part of solar and battery systems as each component generates and runs on different systems which requires inversion.

WHAT ARE THE DIFFERENCES BETWEEN AC AND DC EV CHARGING?

Let's use electric vehicle charging as an example as NSW's EV boom continues. The difference between AC vs. DC electric vehicle charging comes down to how the power is delivered to the EV.

Because the EV battery runs on DC, the energy that is being delivered will need to be or converted to DC power. When DC chargers are used, it alleviates the need to invert the energy before it enters the battery, enabling higher charging rates.

For AC chargers like the popular Tesla Wall Connector Gen 3, it can only deliver a certain amount of power as the charger delivers AC power to the EV which needs to be converted to the EVs required DC power using an onboard inverter.

Onboard EV inverters vary in speeds like how the Tesla Model 3 has an 11kW onboard inverter for AC charging. DC charging doesn't need conversion and can be charged as much faster rates like superchargers that can deliver up to 420kW of power.