In this article, Hoa Binh Electrical Construction Consulting Co.,Ltd provides you some information on advantages and disadvantages of AC and DC cables and which one specializes for solar power system.

1. AC transmission lines

What is AC (Alternative current)?

AC (Alternative current) is the standard one used for long distance power transmission because it is easily converted into different voltages by transformers. It is emitted from an electrical outlet with a cyclic direction.

AC Alternating Current
AC Alternating Current

Some advantages:

  • Cheaper circuit breakers
  • Easy repairment and maintenance and cost-saving
  • Voltage levels change when using transformers.


  • Conductor size: Large
  • High costs of transmission lines
  • Large depreciation with high frequency of use
  • Regular powercut when having no load on the power line or the line is open due to capacitance
  • Inductance problems affecting additional current
  • Additional insulation required
  • AC transmission lines hinder other telecommunication ones
  • Experience problems of stability and synchronization
  • Low efficiency
  • Difficult to control reactive power

2. DC transmission lines

What is DC (Direct current)?

DC is a linear current moving in a straight line. It is used to transmit electricity over short distances because of its low depreciation in the short time. Most electronic devices and household appliances use DC such as lights, refrigerators, washing machines, etc. or solar panels, fuel cells and some generators using DC. It can be generated from AC when using a converter rectifier.

Direct Current DC
Direct Current DC

Some advantages:

  • Only 2 conductors
  • No inductance and surge leading low voltage drop
  • Less insulation thereby less potential stress than AC.
  • Smooth transmission lines with other telecommunications
  • Very low Corona loss
  • No dielectric loss in high voltage
  • Better efficiency due to low prices and insulation
  • Low insulation (70%)
  • Low cable price
  • Low sheath loss in underground cable in DC supply system
  • Suitable for high capacity transmission based on high current transmission
  • Low charging current value


  • Power generated in low voltage due to circuit switch.
  • Unable to upgrade DC due to no activity of transformer on it
  • Less using DC switches and circuit breakers because of cost-consuming
  • Generator used to reduce voltage level with low efficiency than transformer
  • More complicated and cost-consuming transmission system than that of AC
  • Unchanged voltage level leading to inconvenient switch capacity for household appliances (5V, 9V, 20V, etc.) from distributor and transmission lines

3. Difference between AC and DC

AC and DC are quite similar in structure, but they have differences in application and efficiency.

Flexibility: DC is more flexible than AC because light weight and smaill size. Therefore, DC cables are easy to install and use in small spaces. On the other hand, AC cables are more difficult to install and use due to less flexibility.

Safety: DC is safer than AC since DC is difficult to generate induced and leakage currents. Furthermore, DC do not cause electric field interference to other cables in the same manner.

Transmission system: DC is used in direct current transmission and distribution systems such as solar panels or storage batteries. Meanwwhile, AC is used for alternative power supply systems, especially the national grid.

Resistance to voltage drop: Voltage drop means power is not generated when it transmits through a conductor. The voltage drop resistance of DC is better than AC because power transmitted through DC conductors is more effective than through AC.

Application: DC cables are widely-used in solar, wind power systems, electric vehicles, small electronic equipment and some other applications using DC. Besides, it is used in power grids, civil and industrial electrical systems or in other applications using AC.

DC and AC are designed to serve power transmission despite their differences in terms of flexibility, power transmission and resistance to voltage drop.

4. AC and DC, which one specializes for solar power system?

DC cables are commonly used for solar power connecting solar panels and other electrical components of the photovoltaic system. These solar cables are designed to be UV & Ozone resistant, chemical and mineral oil resistant, with excellent Fire-Resistant properties with very little smoke when burned with a heat (fire) outside.

Dedicated DC cable for solar power system
Dedicated DC cable for solar power system

Besides, DC cables are durable in harsh weather conditions, high temperature and outdoors. DC is applied for solar power systems installed indoors in hazardous areas, such as high risk of explosion, in industry and agriculture.

Dedicated DC cable for solar power system
Dedicated DC cable for solar power system


Hoa Binh Electrical Construction Consulting Co.,Ltd (PEC) specializes in providing solar power products and services such as consultancy, design, construction, installation, operation and maintenance of the entire solar power system. They are essential and important for the environment, society and your business.

Hoa Binh Electrical Construction Consulting Co.,Ltd (PEC)

Providing devices and solar power services with our commitment of prestige and high-quality products

Contact information:

Hoa Binh Electrical Construction Consulting Co.,Ltd (PEC)

Address: 91-93 Nguyen Van Yen, Tan Thoi Hoa, Tan Phu, HCM City.


Hotline: 1900 98 98 91

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