John’s Corner :: Where does my electricity come from?

In the last post, I explained that the largest part of your electric bill – up to 75% – pays for the generating plants and the fuel used to produce electricity and that the most common fuels used were coal, natural gas and uranium.

Most electricity is produced by converting coal, natural gas or uranium to heat water to steam, which is then used to power equipment called a “turbine-generator.”  These turbine-generators produce electricity.

Electric generating stations are designed and operated to meet differing needs.  Some plants are designed to operate around the clock to meet the 24 hour-per-day demand for electricity. These baseload plants are usually fueled by coal or uranium. 

Other plants are designed to operate mainly during the daytime hours when the use of electricity increases as people wake up and go to work or school.  These plants often use coal or natural gas. A third type of plant is designed to operate during the “peak” demand periods – usually hot summer days when the demand for electricity soars to meet home and office air conditioning needs.  These “peaking” plants often burn natural gas, but some use fuel oil.

The electricity generated is delivered to customers through a network of wires.  This network has two components.  The first is the high voltage transmission system, large wires on tall towers, which carry large volumes of electricity long distances to the distribution system, the second component of the delivery network.  The distribution system delivers electricity to individual homes and businesses.

(The distinction between transmission and distribution will become important once the discussion turns to current issues.)

More recently environmental and customer concerns have led to the enactment of State laws requiring that an increasing amount of our energy come from “renewable” resources such as wind and sunlight. Wind and solar resources have a number of advantages; however, they only run when the wind is blowing or the sun is shining. There are many consequences of adding large amounts of renewable energy sources to the traditional mix of fuels. We will explore this exciting topic in future posts.

In the next post I will explain some of the physical “laws” governing the transmission and distribution of electricity.

-John