If you have not already read Electricity 101, this article explains what electricity is and Electrical Grid 101 explains how electricity moves from generating stations to customers. Integration 101 explains how electrical utilities are incorporating more renewable generation while keeping the grid reliable for customers.

It is also important to understand how and why electrical grids are ‘balanced’. This article explores what balancing is, why it is important, and how electrical utilities will balance the grid in Atlantic Canada’s net zero future.

Who is balancing the grid?

Before understanding balancing, it is important to recognize how interconnected electrical grids are across Canada and the United States. In a way, this connectivity helps provide backup for the grids. For Atlantic Canada, grids in the Maritime provinces are managed through the Eastern Interconnection (Newfoundland and Labrador is managed through the Quebec Interconnection). These Interconnections also include the Northeastern United States. In a sense, we are all trying to help stabilize each others’ generation highs and lows.

Within each Interconnection are balancing authorities. The New Brunswick System Operator is a division within NB Power which oversees grid reliability in New Brunswick, Nova Scotia, Prince Edward Island and Northern Maine. Its responsibilities include balancing the ongoing changes in demand using the supply available to the grid on a minute-by-minute basis. Each provincial utility has a control centre, and control rooms are in place within most generation facilities to closely monitor and respond to changes in customer demand, frequency, grid supply, and outages, among other responsibilities. These control rooms are always in constant contact.

What is electrical grid balancing?

Grid balancing, also known as frequency regulation, means utilities must constantly match the supply of electricity with the customer demand for it.

The grid frequency of the Eastern Interconnection operates at 60 Hz. This frequency is (usually) determined by the rotating speed of generators. When the grid’s energy generators rotate synchronously, the grid is balanced. If the total electricity supplied on the grid equals the demand from customers, the frequency will remain at 60 Hz. However, if the electricity supplied is greater, the frequency will increase and vice versa.

What happens if an electrical grid isn’t balanced?

Read more

What tools are used to balance the grid?

There are several levels of tools that balancing authorities and utilities can use to ensure the grid remains balanced.

Primary controls: automatic processes that begin within the first few seconds following a frequency change (like cruise control on a car).

Secondary controls: include responses often deployed in “minutes” or less such as opening or closing a hydroelectric dam (like the accelerator or break on a car).

Tertiary controls:  include actions that take place within “hours” such as turning on a natural gas generator to prepare for a colder morning (like an automatic car starter used to warm up your car on a cold winter morning).

Source: NERC, Balancing and Frequency Control Reference Document

What role will electrical grid balancing play in Atlantic Canada’s net-zero future?

As more and more Atlantic Canadians and businesses use electricity for heat,  transportation, and industrial processes, balancing the grid becomes increasingly important. Balancing will also become more complicated, yet crucial as more variable electricity resources (like wind and solar generation) are added to reduce emissions and meet growing electricity demand.

New processes and tools, such as smart grids, battery energy storage systems, and modern dual-fuel combustion turbines can come online and retreat quickly, which will help utilities and balancing authorities meeting these growing challenges. Daily demand-side management and system peak shaving will also be effective tools available to system operators to manage and balance loads.

With balancing and grid stability in mind, utilities also weigh the best options from price, environmental impact, and availability standpoints to ensure the electricity grid remains reliable. The ultimate goal for utilities is to ensure our homes and businesses have the power they need when they need it. As utilities and provinces strive to meet climate goals, modern balanced grids will have a large part to play in achieving these targets.

Resources: