Those who analyze smart grid developments usually talk about whether issues and developments are “up or downstream.” This is generally in reference to whether a particular development falls on the:
- Utility side of the smart meter- dealing mostly with managing the traditional Transmission and Distribution (T&D) system
- Home side of the smart meter- dealing with a range of issues that may affect the individual homeowner.
The issues involved are broadly similar as they all involve data collection on grid status and electricity usage, collating that data and then using it to make key operational decisions about the management of the domain on a second by second basis.
What changes, according to domain, is who is “in charge” of the data, of the software, of the overall system and the precise technical architecture best suited to the domain itself. Therefore, the communications infrastructure needed to take several thousand synchrophasor readings per second from the main grid (and the data analytic algorithms needed to support that process) are wholly different from the communications and analytical requirements for collating data on level of energy use by resident, and modeling customer types on the back of that data.
The T&D objective
The primary focus, for the introduction of smart technologies at the Transmission and Distribution level, is on enhanced fault-detection and self-healing of the network, without the intervention of technical support. To a degree, this occurs already as the basic hierarchic model, used to illustrate the traditional electricity grid, has recently been superseded by radial networks and networks where some degree of re-routing is possible.
In a conventional network, where the flow of current across the grid as a whole or part of it, reached critical levels, it was possible to re-route flows through less-stressed parts of the grid.
The problem with re-routing, however, is that it merely shifts the problem to another part of the network, thereby stressing that element. A domino effect may follow, causing unplanned power outages and thereby inconveniencing network customers.
Alternative techniques for dealing with such situations include a controlled “rolling blackout.” This is where specific regions, covered by a network, are subject to power cuts for a predetermined period of time, or voltage reduction across the entire network.
Although smart technology does not change the essential nature of the problem, it does make information on the current state of the network significantly more available to maintenance personnel. More frequent and up-to-date readouts on the state of critical network components are transmitted. Real-time, rather than historic data is provided.
In addition, smart technology will assist in managing a bi-directional energy grid. Historically, grids were designed with energy flowing out from the centre to point of use. However, local generation raises the prospect of a sub-network which generates more power than it uses. This is both destabilizing and dangerous in a conventional network. This will now change as the smart grid is essentially a “distributed network” with energy flows both out from and in to the centre or, increasingly, from one part of the periphery to another without ever touching the central generating facility.
Smart grid technology will change the way in which the conventional grid operates. Although the smart grid cannot completely eliminate technical faults, it can provide the system with data which will help detect the fault’s location or self-heal without the assistance of physical technical support.