A grid-tied electrical system, also called tied to grid or grid tie system, is a semi-autonomous electrical generation or grid energy storage

Grid energy storage

Grid energy storage refers to the methods used to store electricity on a large scale within an electrical power grid. Electrical energy is stored during times when production exceeds consumption and the stores are used at times when consumption exceeds production...

 system which links to the mains to feed excess capacity back to the local mains

Mains

Mains may refer to:* Mains electricity * Mains power around the world* Electricity transmission* Public utility, "mains services", including electricity, natural gas, water, and sewage disposal...

 electrical grid

Grid (electricity)

An electrical grid is a vast, interconnected network for delivering electricity from suppliers to consumers. It consists of three main components: 1) generating plants that produce electricity from combustible fuels or non-combustible fuels ; 2) transmission lines that carry electricity from power...

. When insufficient electricity is generated, or the batteries are not fully charged, electricity drawn from the mains grid can make up the shortfall.

When batteries are used to store, the system is called battery-to-grid (B2G), which includes vehicle-to-grid

Vehicle-to-grid

Vehicle-to-grid describes a system in which plug-in electric vehicles, such as electric cars and plug-in hybrids , communicate with the power grid to sell demand response services by either delivering electricity into the grid or by throttling their charging rate.Vehicle-to-grid can be used with...

 (V2G).

How it works

Direct Current electricity is passed to an inverter

Inverter (electrical)

An inverter is an electrical device that converts direct current to alternating current ; the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits....

 which is grid tied

Grid tie inverter

A grid-tie inverter is a special type of inverter that converts direct current electricity into alternating current electricity and feeds it into an existing electrical grid...

. The inverter monitors the alternating current mains supply waveforms and generates electricity that is phase matched. The DC electrical system is attached to the mains via this mechanism.

Because the local system is phase matched, electricity can be drawn from the mains in the situation of a generating shortfall or discharge in batteries.

Quality of service

A key concept of this system is the possibility of creating an electrical micro-system that is not dependent on the grid-tie to provide the high level of service quality which is often delivered by a traditional mains supply.

Conversely if the mains supply of the region is unreliable, the local generation system can be used to power important equipment.

Environmentally friendly

Local generation can be from an environmentally friendly

Environmentally friendly

Environmentally friendly are terms used to refer to goods and services, laws, guidelines and policies claimed to inflict minimal or no harm on the environment....

 source such as photovoltaic. Individuals can choose to install their own system if an environmentally friendly mains provider is not available in their location.

B2G also spare the use of fossil fuel power plant

Fossil fuel power plant

A fossil-fuel power station is a power station that burns fossil fuels such as coal, natural gas or petroleum to produce electricity. Central station fossil-fuel power plants are designed on a large scale for continuous operation...

s and electrical substation

Electrical substation

A substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions...

s to supply energy in peak loads of the public electric grid.

Small scale start

A micro generation facility can be started with a very small system such as a home wind power generation or photovoltaic (solar cells) generation system.

Sell to and buy from mains

• Excess electricity can be sold to mains.
• Electrical shortfall can be bought from mains.

List of countries or regions that legally allow grid-tied electrical systems

• India
• Australia
• Belgium
• Bosnia and Herzegovina
• Canada
• Greece
• Hungary
• Israel
• Japan
• Mexico
• The Netherlands
• New Zealand
• Portugal
• Sri Lanka
• Singapore
• Spain
• USA
• Dominican Republic

See also

• Cost of electricity by source
  Cost of electricity by source
  The cost of electricity generated by different sources measures the cost of generating electricity including initial capital, return on investment, as well as the costs of continuous operation, fuel, and maintenance...
  
  
• Distributed network
• Electric power transmission
  Electric power transmission
  Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
  
  
• Grid energy storage
  Grid energy storage
  Grid energy storage refers to the methods used to store electricity on a large scale within an electrical power grid. Electrical energy is stored during times when production exceeds consumption and the stores are used at times when consumption exceeds production...
  
  
• Grid tie inverter
  Grid tie inverter
  A grid-tie inverter is a special type of inverter that converts direct current electricity into alternating current electricity and feeds it into an existing electrical grid...
  
  
• Inverter
  Inverter (electrical)
  An inverter is an electrical device that converts direct current to alternating current ; the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits....
  
  
• Power outage
  Power outage
  A power outage is a short- or long-term loss of the electric power to an area.There are many causes of power failures in an electricity network...
  
  
• V2G
• Electranet
  Electranet
  Electranet is a proposed smart electric grid which would allow people to sell electricity into the grid without any artificial caps. It was proposed in an op-ed article Al Gore wrote in a "My Turn" column for Newsweek in 2006....