How smart is it to deploy smart meters on the smart grid?
Conventional power grids worldwide are beginning to strain against rising energy needs. Blackouts are increasing in number of occurrences. How can we improve these systems in a sustainable way?
One possible solution, of which we have all heard, is the integration of information technology to the electric grid. By integrating modern technology, architectures and tools to the electric grids already employed and in service, as well as integrating these methods into newly planned electric grids, would be a very good start.
Most conventional electric grids are composed of many electromechanical systems and in these existing grids, communication only goes in one direction, to the customer, for the most part. We must have a two-way means of communication to share and use information to improve the service and efficiency of power distribution.
Conventional grid structure has the power generation centralized for the most part. The main power generating center does send the main power to distribution centers for localized distribution to customers.
The smart grid
What is needed is a wider number of distribution sources deployed throughout a region for a true distributed energy architecture, such as the deployment of renewable energy sources—that’s a big part of what we call the smart grid.
In the smart grid case, now even consumers can produce energy as well as distribute excess energy via various means such as solar and wind (even though the power utilities see that as their competition and there is push back here). The smart grid is a properly networked system which has two-way communication capabilities.
Conventional grids are ‘dumb’ and ‘blind’ since they do not monitor themselves using various modern sensor technology like those deployed in a typical smart grid architecture. Sometimes power generating plants do not even know that a blackout or brownout has occurred in a region until they get a phone call from a consumer (the phone systems have battery backup). In a smart grid architecture, numerous sensors are deployed throughout the grid infrastructure that can monitor, test, and communicate. This may even lead to self-repair and healing/removing and re-directing power around faults automatically.
With a communications-enabled utility power meter finding its way into many homes going forward, utility companies and energy regulators seek to take advantage of the technology to improve energy conservation and awareness. Using this concept, sometimes called the smart grid, the utility company seeks to use networks that enter their customers’ homes so they can actively manage the transmission load.
Here in Arizona, as well as in many other portions of the country/world, utilities can now provide real-time price information, thus allowing the customer to adjust their energy usage. For example, during a peak load condition, such as a heat wave (typical in Arizona), the utility company could send a message to the customer, notifying them that prices would be going up for the next hour and encouraging them to switch off appliances. Some sort of in-home display would show this message. Even better, the utility company could communicate to the devices in the home via the smart meter, and turn up the thermostat or turn off a pool pump to help prevent a brownout or even a blackout. This system would need a solid communication protocol between the meter and the home appliances and is sometimes termed the home area network (HAN). 900-MHz radios using the ZigBee protocol are a good possible choice here. See Figure 1 for an example of the HAN.
Figure 1 A home area network example (Image courtesy of Reference 1)
Automatic meter reading (AMR)
With the solid-state electronic power utility energy meter, we could now add a communications link so that if that link was made wireless, a utility van would only need to drive by and collect that data.
Advanced metering infrastructure (AMI)
In this next step of meter evolution, the AMI could be networked with a series of other AMI meters and may employ satellite or low-cost radio links, depending upon the location. The two main RF communication protocols used nowadays are the power line carrier (PLC) and the unlicensed industrial, scientific, and medical (ISM) band. You can fully expect the possibility of 5G to ‘rear its beautiful head’ in a few years.