According to the utility, peak electricity demand July 16 was 4,497 MW. The highest peak demand in 2012 was July 17, when afternoon electricity use spiked to 4,830 MW.
Heat waves put stress on power grids by causing customers to run their air conditioners harder, by reducing the efficiency of transmission and distribution lines and by preventing transformers from cooling off. Toronto Hydro wants business owners to watch their energy usage carefully and avoid the possibility of power outages or soaring electricity bills in the fall.
The utility is asking business owners to refrain from leaving their doors open while running their air conditioners — something that retailers, restaurants and other businesses have been known to do in hot, muggy weather as a way to lure in overheated customers.
Leaving doors opened can waste as much as 3,850 kWh and rack up $500 more in electricity costs, according to the utility. If 1,000 stores closed their doors and used their air conditioners more wisely, Toronto Hydro estimates that up to 3.85 million kWh could be saved.