The key players in the global power industry are planning for investment in the Smart Grid to capitalise on the new opportunities in energy markets.
Given the population growth and exponential increase in electrical power consumption in this increasingly digital world, coupled with the need for electrifying our transportation system (ex: Plug-In Hybrid Electric Vehicles) to lower the dependence on foreign oil, additional infrastructure (power generation, distribution and transmission systems) must be built.
It is estimated that $1.5 trillion will be spent on this infrastructure by 2030. This infrastructure will require a secure, reliable and efficient distribution system to minimise economic losses. It must also be flexible enough to integrate the new alternative energy sources such as wind, solar and other distributed generation sources.
What is the “Smart Grid”?
The electric power industry describes it as “electricity with a brain”, or as a “self-healing” grid. Some utilities are promoting the Smart Grid as the application of Advanced Metering Infrastructure (AMI) to the existing grid, which simply means more intelligent meters and control devices that are consumer interactive. The idea is that smarter customer control devices will receive signals from the grid and process this information based on the customer’s real demand, then make decisions that will save energy by switching some of the consumer loads off during peak demand hours. Such advanced meters and control technology will also help utilities plan better and minimise the use of the traditional and more expensive peak shaving “peaker” power plants.
However, Advanced Metering Infrastructure (AMI) is just one component of the government’s concept of the “Smart Grid”. In addition to advanced metering, key players in the power market realise that there is a need for real-time load monitoring that will integrate information from a variety of sources. It will then use that data to make decisions and utilise controls to rapidly respond to any event with the appropriate solution.
According to the DOE, the new grid infrastructure must be centralised, yet able to operate in isolated sections. This means providing power to a smaller area disconnected from the primary grid, during a failure event. This microgrid structure will require that the grid be able to integrate distributed generation sources that are not usually on the grid during normal conditions. If implemented, the Smart Grid will grow the distributed generation business where small generators and renewable energy sources located close to the load will be the prime source of power during interruption of traditional utility power. These distributed sources can include CHP (Combined Heat and Power) plants and peak shaving generators located in industrial facilities as well as local peaking plants.
Even if they don’t cover all of the consumers’ power requirements while in island mode, distributed generation systems can at least provide power to the most important facilities on the microgrid until conventional utility power returns. Distributed generation can also play a major role on the grid during normal conditions, where their location next to the load can help lower cost, improve reliability, reduce emissions, and expand energy options to the consumer.
While the advancements in telecommunication technologies revolutionised the world in the last few decades, the existing electric power grid still uses similar technologies to that of the original grid designed in the late 1800s and early 1900s. This will change with the new Smart Grid architecture, where digital devices and satellite communication networks will allow a two-way flow of information between utilities and customers. Such a communication network will help ease the congestion of power during peak demand hours utilising remote monitoring capabilities and providing dynamic real-time pricing to customers. That information will allow users to respond to the advanced pricing information, shifting their usage to lower cost “off peak” periods thus helping them better manage their energy costs. This is a far better alternative to the current process of getting their monthly bill and trying to react after the fact. Such communication systems should also be able to track and store data for better planning by utilities and consumers.
Advanced network sensing and modeling devices, combined with digital controls will transform the human grid operator’s role into more of an observer of the system. Since human error is the most common form of failure in complex networks, using microprocessor controls will make the grid more reliable and faster when it comes to preventing blackouts.
Some of the emerging technologies that are expected to be utilised in the Smart Grid are:
Phasor Measurement Unit (PMU)
A system which uses sensors that sample voltage and current at a given location up to 30 times per second. PMU is much faster than the existing Supervisory Control and Data Acquisition (SCADA) sampling system that samples 2 to 4 times per second. Such enhanced sampling allows better diagnostic capabilities, making the grid more intelligent when it comes to predicting surges and outages.
Distribution Management System (DMS)
Power flow monitoring software that (in study-mode) can be used to run different grid operation scenarios pulling data from a centralised database that is always updated and synchronised with the network. This database has all the information needed to simulate situations such as three-phase unbalanced power flow, or perform contingency and short circuit analysis.
Visualising Energy Resources Dynamically on Earth (VERDE)
Similar to Google Earth, VERDE simulation allows grid modeling with geographical information using real-time sensor data and weather information. This will enable the operator to visualise the condition of the grid at different levels, switching the view of the grid display from national to regional or even street level, all within a few seconds.
The new grid structure will also require advanced components in the following areas:
Technologies such as Hybrid Air Conditioning systems can convert electrical energy to thermal energy and store it. This is more economical than storing electricity in batteries.Such storage capabilities will be needed to grow the alternative energy sources, where unstable power flow from renewable energy plants such as wind and solar farms can be stored and better controlled. It can also supply power to the grid when it goes into island mode as explained above, or even reduce congestion of power on the grid during peak demand.
Superconductive power cables
Research in superconductivity could result in the wide use of superconductive power cables. Such cables will reduce line losses in the distribution system while carrying 3-5 times more power than the traditional copper-based cable, making it a more efficient system.
There are many theories about what the future Smart Grid should utilise, what it is and what it isn’t, but the intent of this paper to give a simple description of the Smart Grid and its objectives, which can be shown in the FIGURE 3 from a white paper by D. Sc. Massoud Amin, a professor of Electrical and Computer Engineering at the University of Minnesota, and a well known scholar in the Power and Energy Industry.