Energy and the City

Electricity is generated primarily by burning fossil fuels such as coal, natural gas, and oil, and to a lesser extent through nuclear fission, dams, solar power, etc. As power plants generate electricity, it is transported across long distance, hi-voltage transmission lines to numerous substations that convert it to lower voltage power for ultimate delivery to your home or business via local distribution lines.

How is electricity measured?

A. Electricity is measured in kilowatt-hours (kWh). One-kilowatt hour is 1,000-watt usage in one hour. For example, if you leave 10 lights (each with 100 watt bulbs) on for 1 hour, you will use 1kilowatt-hour of electricity.
What home appliances consumes a significant amount of electricity?
A. Homes with central air conditioning utilize an enormous amount of energy. Although they typically are used a few months of the year, the annual cost can be much greater than the annual cost of your refrigerator, which is typically the second largest energy consumer.
Is it more efficient to leave computers on at all times or turn it off when they are not being used?
A. It depends. The typical computer consumes approximately 100 Watts, or 2.4 kWh/day. By multiplying your electricity rate per kWh, you should come up with the cost per day. Leaving a typical computer on at all times would cost approximately 21�/day (2.4 kWh * 8.6�/kWh). This adds up to almost $75/year. In general, repeatedly turning your computer on & off does not consume as much energy as leaving your computer running all day. However, the cost to leave your computer on 24 hours a day is necessary if you utilize your computer as a web server or if you also have a fax machine hooked up to your computer.
Is it more efficient to switch the lights off when leaving the room for a short period of time or do lights consume more electricity to turn them back on?"
In general, turning lights (fluorescent and incandescent bulbs) off is more energy-wise. In the past, it was true that fluorescent lights utilized more energy to start up again. Today, technology has improved fluorescent lights so that they do not use appreciably more energy to start up. Turning fluorescent lights on and off does slightly shorten the lifetime of the bulbs, however, you will have to replace the bulbs less frequently if they are not running all day long. Incandescent lights do not require additional energy to start.