Committed Earth Hour observers who spend Saturday evening unplugging appliances and dining by candlelight might also be interested in learning how much they actually contributed to the collective conservation effort.

This information will be available Sunday on the Toronto Hydro website (, which monitors hourly electricity use for each and every customer.

The site, by the way, is pure, uncut, addictive energy conservation porn.

Last Sunday, for instance, I spent 14 cents on 3.082 kilowatt hours of electricity between 10 and 11 p.m. because I ran a long, hot bath that sent the electric water heater into conniptions. Earlier in the day, between nine and 10 a.m., I was away from the house, electricity consumption was minimal and I added only one cent to my bill.

But weekends — when the price of electricity is a constant 4.4 cents per kilowatt hour — are relatively dull times for power consumption viewing. Things are much more interesting during the week when time-of-use pricing dictates that power costs 9.3 cents per kilowatt hour in the morning and evening, eight cents in the afternoon and 4.4 cents overnight.

This means even the ­tiniest acts of electricity gluttony at the “wrong” time of day translate into higher costs. One cold, blustery Tuesday morning in January, for instance, I did laundry and ran an electric heater in my home office. My electricity costs ranged from 23 to 32 cents per hour.

About 100,000 Toronto Hydro customers (20 per cent of the total) have registered with the utility to track their household electricity consumption on-line. The bar graphs and charts have me hooked. And other users are finding out way more than they bargained for.

“Parents have found out their kids are coming home from school when they shouldn’t be,” says Toronto Hydro’s Tanya Bruckmeuller.

“They’ll see a spike (in electricity consumption) in the middle of the day.”

The website’s purpose — apart from tracking Earth Hour conservation efforts and juvenile scofflaws — is to shift electricity consumption to off-peak hours. Doing laundry in the middle of the night rather than during the supper hour, for instance, means we don’t need as many power-generating plants to handle peak demand.

The problem is, I don’t want to do laundry in the middle of the night. Then again, I wonder what that bar graph will show if I run the clothes dryer at 3 a.m?