With the increase in renewable energy sources the grid is becoming more complex and needs more careful control to be efficient.

A grid is the set of wires between suppliers and customers. The historical model is one of generators sending power one way to the customers. However with power coming from customers and other variable sources such as wind, solar PV, tides, etc, the picture becomes more complex.

A smart grid is made possible because data can be sent along the power lines.This allows computers to better control the allocation of electricity. Customers with a smart meter can and send and receive data. So if the price of electricity suddenly increases because the wind and sun has dropped, then the customer's smart meter may turn off non essential item such as pool pump, outside lighting, air conditioning, etc. If the wind is strong, and the sun it blazing, then the price will fall and the information goes out to all customers. The smart grid may detect the electric vehicle is plugged in and will charge it. If the price rises again, it may sell power from the car's battery.

A smart grid can respond to sudden problems such as power lines down and a generator off line by re routing the power lines and starting up a new power source. It should be able to self heal. It should be able to set prices and manage loads efficiently. It should be able to work out when to store and retrieve electricity.

Standard grid - power one way to customers

How is the data sent?

The data is sent in bursts during the small period of time when the alternating current changes from one direction to the other.

It can also be sent by wireless.

Installing smart meters in Victoria Australia

The Victorian Government is rolling out smart meters to all households and small businesses. More than two million homes and 300,000 businesses will have their older type electricity meter replaced with a smart meter.

Smart meters can:
• Record electricity consumption in thirty minute intervals.
• Be remotely read, so a meter reader does not have to visit your home or business.
• Enable the remote connection of your electricity when you move to a new address.
• Help distributors to detect and locate power outages and restore supply more quickly.

 At the 2011 Smart Grid World Forum in Beijing late last month, China’s State Grid Corporation announced plans to invest $250 billion in electric power infrastructure upgrades over the next five years, of which $45 billion is earmarked for smart grid technologies. According to its three-stage plan, China will invest another $240 billion between 2016 and 2020 (including another $45 billion toward smart grid technologies) to complete the build-out of a “stronger, smarter” Chinese power grid.

Climate Spectator - Read more..

"The main difference between a smart grid and a conventional grid is that smart grid components (similar to smartphones) are upgraded to include sensors, computers, and a wireless interface. That means the bits and pieces of the electric grid – the transmission wires, transformers, distribution wires, and usage meters – transmit and distribute electricity more efficiently and reliably to end users, and they can also report back on how that process is going and adjust operations along the line to fit changing conditions.

This smart functionality is critical for integrating key elements of a clean energy future, such as renewable power generation and electric vehicles. Unlike traditional coal-fired power, renewable power can be decentralized (multiple wind farms instead of one massive coal-fired power plant) and is often weather dependent. Conventional grid systems are designed to transfer a steady and predictable flow of power from point A to point B. When a thunderstorm reduces solar panel output or increases wind turbine output, those power fluctuations can trigger blackouts and burnouts in a conventional grid system. But a smarter grid can adjust, either by storing excess energy in batteries until it is needed or by moving power more efficiently across longer distances.

Smarter grids are also better at handling higher and more variable demand loads, and that will be critical when more electric vehicles are added to the system. Current consumer demand is very predictable, so utility companies know exactly what times of the day to purchase and distribute extra power to counteract daily peaks. Electric vehicles likely will not follow traditional consumption patterns – meaning demand peaks will be harder to anticipate – and that will create new operational challenges that will be hard to address without a more automated system."  Climate spectator

The AEMC reports that national networks now include $11 billion worth of assets that are used for only 100 hours a year.

National Energy Market - NEM

The NEM contols the pricing and despatch of electricity to the national grid.

The National Electricity Rules allows for three types of bids, each of which are subject to a floor price of -$1,000 and a ceiling price of $10,000 per megawatt hour.

Daily bids are submitted on the day before supply is required and are incorporated into the forecasts that are prepared prior to dispatch;

Re-bids can be submitted up to five minutes before dispatch and allow the generator to alter the quantity of electricity it will supply, however generators are not permitted to change the price of the bid;

Default bids are those that stand when no daily bid has been made, they generally are ‘commercial-in-confidence’ and reflect the base operating level of a given generator.

Dispatch process and the spot price

In the dispatch process, once the bid stack has been formed, NEMMCO uses this information to dispatch generators into production every five minutes. The price at which the generators

are dispatched (otherwise known as the dispatch price) is calculated by reference to the bid submitted by the most expensive generator that is required to be dispatched into production.

 The spot price is calculated every half hour by averaging the six dispatch

Source the Wholesale Electriciy Market

If I ran an electricity network

Energy Spectator