Understanding the Electric Grid, the Backbone of the Modern World
Electricity is such a vital part of our daily lives; that we often don’t think about how it is generated or how it reaches us. When we flip a switch or plug in an appliance, we expect the lights to come on and the devices to work. But behind the scenes, there’s a huge system that makes all this possible—the electrical grid.
The electrical grid is a network that delivers electricity from power plants to homes, businesses, and other facilities. It’s essentially a series of power stations, transformers, transmission lines, and distribution networks that work together to move electricity from where it’s generated to where it’s used.
Thomas Edison is often credited with creating the first real electrical grid in 1882. In the early 1900s, as the need for power grew, grids expanded from small urban areas to larger cities, and then to rural areas. One of the key milestones was the development of alternating current (AC) systems, largely credited to Nikola Tesla and George Westinghouse. The introduction of AC allowed electricity to be transmitted over much longer distances.
How does it work?
The electrical grid has three main stages of operation: generation, transmission, and distribution.
Generation: Electricity is produced at power plants. These plants can generate electricity from various sources: fossil fuels (coal, natural gas), nuclear energy, or renewables (wind, solar).
Transmission: Power plants are not essentially located close to us, so once the electricity is generated, it needs to travel long distances to reach homes and businesses. Transmission lines help to mitigate this issue, electricity usually loses energy as it travels long distances, so it is sent through transmission lines at high voltage. This high-voltage electricity travels through large power lines stretching across cities, states, and even countries. The higher the voltage, the less energy is lost during transmission.
Distribution: This high-voltage electricity then reaches a local substation, where the electricity is stepped down to a lower voltage that is safe for use in homes and businesses. More substations and smaller transformers help to further lower the voltages, and divide the electricity among subdivisions.
Source: EIA
A key component of the electrical grid is the electric utility. An electric utility is a company or organization responsible for generating, transmitting, and distributing electricity to homes, businesses, and industries. These utilities typically operate power plants, substations, and the transmission and distribution networks that deliver electricity.
Let’s take a quick look at the basic parts of an electrical grid:
Power Plants: These are where electricity is generated. They can be coal, gas, nuclear, or renewable power plants.
Transformers: These devices are used to change the voltage of electricity, either stepping it up (for transmission) or stepping it down (for distribution). These are located at many places in the power grid, at substations, and at generating sites, that is wherever there is a need to change voltage, it is the go-to.
Transmission Lines: These are the High-voltage lines that carry electricity over long distances. They’re typically seen on large metal towers or poles and are crucial for getting power from power plants to local substations. Transmission lines are either overhead power lines or underground power cables.
Substations: Substations are where the high-voltage electricity is converted to lower voltage for distribution. This is also where the grid can be divided into different regions to direct power to specific areas.
Distribution Lines: These are the smaller power lines you see running through neighbourhoods. They carry lower-voltage electricity from substations to homes and businesses.
Meters: Electric meters are installed at homes and businesses to measure how much electricity is being used. This data is used to calculate billing.
The Balancing Act
For the grid to work, it needs to be stable. In other words, the electricity supply must match the electricity demand at all times.
That’s the responsibility of balancing authorities, usually local or regional electric utilities. These authorities are making sure that enough supply is available to cover that demand, and managing the transfer of power with their counterparts in other sections of the grid.
Now, since power generation comes from various sources, all of which have their pros and cons - Nuclear and coal-powered power plants generally provide a stable consistent source of power. But most of these plants are aging, hence difficult to provide flexible power generation.
Renewables, on the other hand, are intermittent in nature, that is solar energy is not available at night, and wind energy can only be produced when the wind blows, hence affecting grid stability. If supply and balance fall out of balance, localized or widespread blackouts can occur.
So, there is always a constant balancing act taking place to ensure stable power. Utilities forecast electricity usage and adjust power generation to ensure they meet the demand in real time. On days when demand spikes (e.g., during heat waves when air conditioners are running), utilities must have backup power sources. This could be from peaking plants or battery energy storage.
The Modern Shift
The grid is often criticized for its outdated infrastructure, but the reality is that overhauling such a vast, interconnected system is a complex challenge. However, the modern world is coming up with innovative solutions to address these issues. To enhance reliability and reduce costs, utilities are implementing smart grids, advanced metering infrastructure, distribution automation, and optimizing distributed energy resources (DERs).
Smart Grid: A smart grid is an advanced electrical grid that uses digital technology to monitor and manage the flow of electricity more efficiently, reliably, and sustainably. Unlike the traditional grid, which is largely mechanical and one-way (from power plants to homes), a smart grid is dynamic and interactive, using real-time data to optimize electricity distribution and consumption.
Advanced Meter Infrastructure: Advanced metering infrastructure (AMI) is an integrated system of smart meters, communications networks, and data management systems that enables two-way communication between utilities and customers. AMI also enables utilities to offer new time-based rate programs and incentives that encourage customers to reduce peak demand and manage energy consumption and costs.
Distributed Energy Resource: Distributed energy resources are small, modular, energy generation and storage technologies that provide electric capacity or energy where you need it. DER systems may be either connected to the local electric power grid or isolated from the grid in stand-alone applications, eg: rooftop solar, energy storage, and wind turbines.
Integrated Resource Plan: An Integrated Resource Plan (IRP) is comprised of an assessment of the future electric needs and a plan to meet those future needs. It is integrated in that it looks at both demand side (conservation, energy efficiency, etc.) resources as well as the more traditional supply side (generation/power plants, transmission lines, etc.) resources in making its recommendations on how best to meet future electric energy needs in the state.