When it becomes fully implemented, the smart grid will resemble an energy Internet, perhaps eventually worldwide.

Its defining and somewhat surprising characteristic is that it is a two-way affair, which is to say that it is interactive.

Traditionally, power grids have been seen as ways to organize power generation and distribution systems. Outstanding among these systems are the North American Grid, comprising the United States, Canada, and parts of Mexico, UK’s National Grid, and Grid Australia.

The theory, which has been largely successful, has been to interconnect power providers, despite the fact that they are under different ownerships, so that generating plants and the customers can be patched and matched in a flexible manner as needed to maintain continuity of service for everyone despite local outages and temporary shutdowns for maintenance.

With the introduction of the smart grid, the focus shifts in part to the customer. The theory is that two-way communication between the utility and the customer will permit both of them to make and implement decisions concerning generation and usage of electricity so that peak demand is reduced and better use of existing generating resources will result in lower cost (or at least minimize rising costs) to the end user.

What makes this possible, at least for a start, is the smart meter, a unique and fundamental part of the smart grid. Smart meters, besides reading electrical usage, are able to read premises sensors, report power outages, detect power quality problems, and even function as an arc-fault detector for the entire building.

There are several smart meter manufacturers, who market them worldwide. For about $200 each, the utility can purchase smart meters and in a change-over program, install them at customers’ premises. The old conventional meter is removed from the meter socket and the smart meter inserted, with no other changes in the building wiring.

A typical smart meter has large copper conductors rated at 200 amps. They are connected to the input and output lugs of a conventional meter socket. In place of a motorized gear train, the conductors are inductively coupled to current transformer windings. A small current is sampled periodically and the information is transmitted to the utility. The traditional human meter reader is no longer in the picture. The smart meter has a local area network (LAN) ID number so that it can communicate by means of Internet Protocol.

A user interface in the form of a control panel in the home or business, or alternatively, a website that can be accessed by means of a user name and password provides usage information in real time so that the customer can adjust premises loads in order to take advantage of lower off-peak rates. The capability yields a number of benefits:

The customer will see a lower monthly bill.

The utility will see a more level demand. Since peak demand determines to a large extent the operating cost, this is good news for the power provider.

The nation and indeed the entire world will see cleaner air, reduced carbon consumption, less global warming.

Economic development can accelerate in positive directions as inefficient energy use declines.

When we consider the smart grid, the smart meter is not the whole story. It relates to the interaction between utility and customer, but there is also communication and active control that takes place within the utility (between the central monitoring location and the individual substations) and among the utilities.

Just as the smart meter enables customer and utility to communicate, Supervisory Control And Data Acquisition (SCADA) allows many unmanned electrical substations to interact in a two-way fashion with a single central monitoring facility. This high-tech electronic protocol is used for many industrial processes such as airports, wind farms, gas and oil pipelines and refineries, and water treatment plants. SCADA was a forerunner to the smart grid and where it is already in place, it will dovetail efficiently with the smart grid. The defining component is an advanced human-machine interface (HMI). Programmable Logic Controllers (PLCs) and Remote Terminal Units (RTUs) work together to monitor and control the substation. The link between substation and monitoring facility may be radio, telephone, optical fiber, internet, hardwire or other medium.

Proprietary SCADA-based software programs on CDs are installed into one or more computers at the monitoring site. A graphic display allows the human at the monitoring site to exercise control options for routine maintenance or in the event of malfunction. Where possible, an appropriate response is made via the SCADA link. If necessary, a repair crew with necessary tools and materials is dispatched to make repairs. SCADA is far more economical that having full-time workers at each substation. SCADA enables remote workers to poll each substation at preset intervals, or where necessary the unmanned substation can initiate an unsolicited communication.   

Worldwide, the principle power providers have taken preliminary steps to implement smart grids. Some utilities that are part of the North American Grid have pulled old-world mechanical meters, replacing them with smart meters. Other utilities, in some localities the larger ones, have been in no hurry to get started due to the large capital investment required. Where the smart meters are in place, for the most part they are being used solely to report electrical usage for billing purposes. The vast potential functionality for more efficient energy us is not yet a reality. SCADA is accepted technology but inter-utility optimization remains a patchwork affair, essentially unchanged since the 1970’s when it was upgraded in response to the massive East Coast blackout.

In the UK, the Department of Energy and Climate Change is the key player in the move toward a smart grid. The agency is committed to reducing greenhouse gas emissions in the UK by at least 80 percent by 2050. The agency believes electrical generation can be decarbonized and supply and demand can be matched in real time. To this end, DECC is rolling out smart electric meters to all UK homes by 2020. Meanwhile, massive funding has been committed to support grid trials.

Australia, through the Smart Grid Smart City program, is actively testing a range of smart grid technologies, including smart sensors, new back-end IT systems, smart meters and a communications network. The Australian government’s Department of Resources, Energy and Tourism is currently saying that Smart Grid Smart City will deliver Australia’s first commercial-scale smart grid. Ausgrid is working with IBM Australia, GE Energy Australia, Sydney Water, Hunter Water and Newcastle City Council to deliver the project.

The project’s main focus is Newcastle, New South Wales, but it will conduct experimental installations in Sydney, CBC, Newington, Ku-Ring-Gai and the rural township of Scone. So it seems that of the major grids in the world, Australia may be the first to have a fully realized working smart grid. With vast amounts of capital entering the country from the sale of raw materials to China, the opportunity exists for this sort of infrastructure investment.

In many parts of the world, rapid developments in solar photoelectric technology are adding a whole new dimension to an incipient smart grid environment. The simplistic view is that stand-alone systems would replace extensive grid development, but in actuality, the synchronous inverter-based system is far more economical than the battery backup concept, so it seems like these technologies will come together to benefit all of us.