Electricity is supplied to homes and businesses in the United States in the form of alternating current, and frequency is the rate at which an alternating current changes direction, as measured in hertz (Hz). Across the power grid there is a consistent frequency which in the United States is 60 Hz. 

The ability of the grid to react to a change in

the frequency to bring it back to the normal operating frequency, which is 60 Hz in the United States

• Inertial response refers to the injection of stored energy, such as battery energy, into the electricity grid to slow down a decline in frequency. 
• Primary frequency response – The first line of defense against frequency fluctuations that could destabilize the grid. It takes the form of immediate, automatic adjustments in power output by generators and loads in response to frequency deviations in the electric grid.
• Fast frequency response consists of the combined inertial response and primary frequency response. It injects energy in the seconds immediately following a disturbance to slow frequency decline and establishes the minimum frequency (called the nadir).
• Secondary frequency response works on a slightly longer time frame than primary frequency response, on the order of 5-15 minutes. It maintains grid frequency and allows for scheduled energy transfers between balancing authorities, which include utilities, regional transmission operators, and other grid management entities.

Measure of the rate of energy transfer over a unit of time, with one watt equal to one joule (J) per second.

A form of renewable energy that uses the kinetic energy of wind to generate electricity. It involves capturing the wind’s energy through turbines, which then convert this mechanical energy into electricity. Modern wind power generation primarily relies on wind turbines, often grouped into wind farms, connected to the electrical grid.

The increase in energy demand during the winter months, usually due to heating needs. This can lead to higher energy prices and bills for a number of reasons, including: 

• Strained energy grid: The high demand can strain the energy grid, which can cause utilities to work harder to meet the need.
• Seasonal rate adjustments: Many energy providers adjust rates based on seasonal demand.
• Increased use of lighting: Shorter and darker winter days can lead to greater use of in-home lighting.