Why is AC better for long distance power transmission than DC?

Transmission due to the ease of voltage transformation using transformers, which allows for efficient reduction of current and minimizes power losses. While DC power transmission has its advantages, particularly for very long distances and subsea cables, AC's compatibility with existing infrastructure and widespread use makes it the standard for most power grids. 

Here's a more detailed explanation: 

Advantages of AC for Long-Distance Transmission: 

Efficient Voltage Transformation:

AC voltage can be easily stepped up or down using transformers. This is crucial for long-distance transmission because high voltage reduces current, which in turn minimizes power losses due to resistance in the transmission lines.

Reduced Power Loss:

By using high voltage AC, the current is reduced, leading to lower I²R losses (heat losses) in the transmission lines. This makes AC more efficient for delivering power over long distances.

Established Infrastructure:

AC power grids are widely established and have been deployed for decades. This means the infrastructure (transformers, transmission lines, etc.) is readily available and relatively cost-effective to maintain compared to building new DC infrastructure.

Compatibility with End-Use Devices:

Most electrical devices and appliances are designed to operate with AC power, making it a convenient choice for power distribution. 

Why not DC for Long Distance?

While DC has its advantages in certain situations (like HVDC for very long distances and subsea cables), it faces challenges:

Voltage Transformation Complexity:

Converting DC voltage is more complex and expensive than AC voltage conversion. While solid-state converters are now available, they add to the cost and complexity of DC transmission. 

Higher Initial Investment:

Building and maintaining DC transmission lines can be more expensive than AC lines, especially when considering the cost of conversion equipment at both ends. 

Limited Infrastructure:

DC infrastructure is not as widely established as AC, which can make it less practical for general power distribution. 

In summary: AC is the preferred choice for long-distance transmission due to its ease of voltage transformation, reduced power loss at high voltages, and the availability of existing infrastructure. While DC is used in specific applications, particularly for very long distances, AC remains the dominant standard for most power grids.