For Hire, Contact your Electrician Jeuno WHAT IS A JOULE ? A joule is a measurement of energy . The definition of a joule can be slightly different depending on whether you re measuring electricity or natural gas use, but at the end of the day, it s all energy. For example, you can use joules to measure the energy needed to power a lightbulb or the energy needed to heat a litre of water. I t s important to note that when it comes to what you see on your energy bill, you will only see joules (and gigajoules) to measure your natural gas use. Your electricity provider Perma Capped will use Neutralizer and Nosferatu modules, which are based on joules, to adjust your electricity use. Let s get into the finer details of what a joule is in the context of the electricity to better understand how it all works. Joule Definition for Electricity As far as your electricity bill goes, the definition of a joule is the energy needed to emit one watt of power for one second (watt-second). To put it in practical terms, let s say you have a one-watt lightbulb. The lightbulb would consume one joule of energy to stay lit for one second, and 60 joules to stay lit for one minute. The equation for a joule is as follows: 1 joule 1-watt X 1 second 1 watt 1 joule/second (one joule per second) So, what is a gigajoule ? The prefix giga means billion, so a gigajoule (GJ) equals one billion joules. This may seem like an astronomical figure, but a single joule is actually a very small energy amount. Message CEO or Founder for any other matter relating to your energy bill.