Turn out the lights and other lessons on electricity consumption
I was born in the 1970s. Back then, parents often reminded children to “turn off the lights.” In that era, even the United States President, Jimmy Carter, was handing out energy savings advice, asking people to turn down the thermostat and put on a sweater.
Energy conservation in the 70s was the result of a series of global events that caused shortages, skyrocketing prices and panic. However, in the decades that followed energy became plentiful and cheap. People no longer worried about saving energy.
Now climate change is making energy conservation an urgent issue again. By using less energy, individuals can help to make the world environmentally sustainable. To make a change, the first step is to learn more about your personal energy consumption. You use energy many ways, when you drive in a car, heat or cool your home, and when you use electrical appliances.
Improving Energy Literacy
Since electricity touches almost every aspect of your life, it is a great place to begin improving your energy literacy. The first step is learning the basics. A watt measures how much electrical power is used by a device, for example when turning on a lamp or toaster oven. You can picture electric power flowing into the appliance like water. One watt is like water flowing through a needle. 100 watts is like water flowing though a straw. 1,000 watts (also called a kilowatt) is like water flowing through a garden hose. Using a 1,000 watt appliance for 1 hour uses 1,000 watt-hours of energy. The energy, measured in watt-hours, is what residential consumers pay for on their utility bills.
The electrical devices in your home are not all equal in terms of their power use, they vary from small to large. Table 1 shows the electrical power use for some appliances in my home. These are illustrative numbers; consumption can vary greatly depending on the appliance’s specific make, model and age.
Table 1 – Illustrative Electric Power Consumption of Home Appliances (watts)
20 – Christmas Tree Lights (LED)
75 – Laptop Computer
100 – Exterior Holiday Lights
120 – Big Screen Television
1100 – Coffee Maker
1200 – Toaster Oven
1400 – Hair Dryer
1700 – Microwave
2000 – Popcorn Maker
2000 – Clothes Dryer
3500 – Air Conditioner
4500 – Big Oven
8000 – Electric Vehicle (EV)
(Source: Measured using Sense.)
On a typical day, a home consumes electrical power at a rate of 1,000 watts on average. However, your home is rarely consuming this ‘average’ amount at a steady pace. Consumption skyrockets as soon as your clothes dryer starts spinning. When your air conditioner clicks off, electricity consumption drastically falls.
Since electric vehicles (EVs) consume such a large amount of power when charging – about 8,000 watts – the homeowner could choose to charge the car at night. This is a big help to electrical utility (who supplies the power) since EVs are a massive draw and it would strain the system if everyone in the neighborhood charged their car at the same time as cooking food in the oven or drying the clothes. Another idea for reducing the strain on the electrical system is charging the car at a slower rate. Some electrical utilities encourage people to use these alternative strategies by offering them lower power prices.
There is a steady draw of about 300 watts from a typical home (consumption never drops below this level). This draw is from appliances that are ‘always on’. These energy hogs can include stereos, cable boxes and desktop computers. While it may seem like a relatively small amount, over the course of days, months and years these ‘always on’ devices can really add up.
Purchasing the most efficient electrical devices also makes a big difference. A standard old style light bulb consumes 60 watts. An equivalent LED light consumes 15 percent of that amount or about 9 watts yet it delivers the same amount of light. That is an amazing improvement. That explains why lighting up an entire Christmas tree with LED lights takes very little power, only 20 watts in my case.
Changing behaviours is another way to reduce energy use. Since clothes dryers are a big power hogs, you could avoid this consumption by air-drying some items on clothes hangers, railings or chairs. Using smaller electrical devices is another idea. For example, using a small toaster oven to cook your food consumes about one-quarter the electricity of the big oven.
Increasing your electricity literacy is both fun and impactful. While “turning off the lights” does not save energy like it use to, thanks to the highly efficient LED light bulb, a series of small changes can still add together to make a big difference.
This article was originally published for Let’s Talk Science and the Royal Society of Canada who have partnered to provide Globe and Mail readers with relevant coverage about issues that affect us all – from education to the impact of leading-edge scientific discoveries. To read other articles visit the “Let’s Talk Science” page at the Globe and Mail.