Computing and Environmental Stewardship

A device's life has five stages: extracting the raw materials, manufacturing, transport, use, and end of life. For laptops, tablets and phones, manufacturing is usually the largest share of the lifetime footprint, because making chips and displays is extremely energy-intensive and the devices themselves sip power once built. For desktops, servers and gaming machines that run for many hours at high power, the use stage grows much larger. Where the electricity comes from matters too. Most of Ontario's electricity is generated from nuclear and hydro, so a kilowatt-hour used here carries less carbon than one from a coal-heavy grid — which makes manufacturing, which often happens elsewhere, an even bigger share for an Ontario user. The practical conclusion is the same either way: the greenest device is usually the one you already own, kept running longer.

A power rating in watts (W) says how fast a device uses energy. Your electricity bill charges for the total energy used, measured in kilowatt-hours (kWh): one kilowatt-hour is a 1000 W device running for one hour, or a 100 W device running for ten. So the method is always the same three steps. Convert watts to kilowatts by dividing by 1000, multiply by the hours of use to get kWh, then multiply by the price per kWh. In Ontario the price of the electricity itself depends on the time of day and the price plan — very roughly 8 to 20 cents per kWh on the common plans — with delivery and regulatory charges on top. This lesson uses 0.12 dollars per kWh as a round, approximate rate; always state the rate you assume, because the answer scales directly with it.

Two labels make purchasing policies easy to write. ENERGY STAR, a program of the United States Environmental Protection Agency that Natural Resources Canada administers here, certifies products that meet energy-efficiency targets, including low power use in sleep and standby. EPEAT, run by the Global Electronics Council, goes further: it rates products across their whole life cycle — energy use, hazardous materials, recycled content, ease of repair and recyclability — in Bronze, Silver and Gold tiers. At the end of a device's life, Ontario makes producers, the companies that sell electronics, responsible for collecting and recycling them. Since 2021 this has been set out in a regulation under the Resource Recovery and Circular Economy Act, 2016, overseen by the Resource Productivity and Recovery Authority. In practice that means free drop-off at municipal depots, participating retailers and producer programs such as Recycle My Electronics, which lists locations across the province.

Software decides how hard the hardware works, so programmers have their own lever. An efficient algorithm does less work for the same answer — binary search's 20 checks against linear search's million is an energy saving as much as a time saving, and it is multiplied across every user and every run. Moving less data helps too: compressing images, caching results instead of fetching them again, and not polling a server every second when a notification would do. In the cloud, the biggest waste is often resources nobody is using, such as test servers left running all weekend. Data centres measure their overhead with power usage effectiveness, PUE: total facility power divided by the power reaching the computers. A PUE of 1.5 means half as much energy again goes to cooling and power conversion; the most efficient large facilities report figures close to 1.1. Choosing a provider region with a low-carbon grid, such as Ontario or Quebec, can matter as much as any efficiency measure.