Chris Tyrrell Answers More of Your Energy Questions

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Question 1: Is there a way to store up the energy I generate in the summer to use in the winter?

This is a great question and I believe there is a lot of future potential for energy storage but the technology is still relatively new and currently not cost effective for residential customer applications.  However, energy storage technologies are maturing on a larger commercial scale and are starting to be deployed in utility infrastructure to optimize the use of the distribution grid and provide a more reliable electricity supply.  I suspect in a few years, they will be more readily available in the residential market sector to enable you to store energy at night when the price of electricity is low to be used during peak periods of the day when the price is much higher.

Question 2 How much electricity does an air conditioner really use? What are alternatives to this?

An average home’s central heating and cooling system accounts for approximately 60 per cent of the yearly energy bill.  The electricity usage for the air conditioner (AC) depends on the make and model, as well as the age of your particular unit.  As an example,  a central air conditioning unit (typical size 2.5 tons or 30,000 BTUs), would use approximately 525 kWh/month or approximately $73/month - assuming 150 hours of usage per month. If you use a window air condition unit (typical size 7,000 BTU ), the average electricity consumption is 112 kWh per month or $16/month. 

Whether you have central air conditioning or a room air conditioner, it is important to ensure it’s a high efficiency air conditioner, and operate it responsibly (see tips in question 3 below). Alternatives or ways to minimize air conditioner consumption include having fans in every room, using window blinds or awnings and opening windows at night when the air is cooler and less humid.

Question 3: How do I get the most out of my AC without increasing my power bill?

There are a number of ways you can get the most out of your AC unit and limit your consumptions as follows:

  • Installing your air conditioner in a shaded area. An air conditioner that is exposed to direct sunlight will consume 5 per cent more energy than one that is shaded.
  • When you turn it on, do not switch your thermostat to a colder setting than you need. It will not cool the room any faster. As a rule of thumb, your thermostat should be set to 25.5° C (78° F) or higher if comfort permits.
  • Turn off your air conditioner when you are not home or program the thermostat to turn on the AC on just before you get home.
  • Utilize fans to help circulate air. Even with air conditioning, fans will make you feel cooler and reduce the amount of time you need to run your air conditioner.
  • Make sure the distribution of air is getting to the most common occupied space.  Basements are normally cooler as they have less heat gains.  If your central ducting system is distributing AC to the basement, block off some of the basement ducts to force more air to upstairs occupied areas

To help your wallet and the environment this summer, sign up for peaksaver. Toronto Hydro will install a small wireless device near your central air conditioner to reduce its energy use during times of peak electricity demand – there’s no cost to you, in fact we offer a $75 credit on your electricity bill when you join peaksaver

Also, our Great Exchange program allows Toronto residents to exchange their old, inefficient room air conditioners for a $25 gift card. For dates and locations visit

Question 4: In the summer, are there appliances I should have serviced before turning on?

After a long and hard Canadian winter, it is always a good idea to have major appliances that have been left idle checked. If you had your A/C unit winterized by a professional in the fall, you are probably in good shape when the summer rolls around. However, it is always a good idea to have your A/C unit serviced in the spring before the first big heat wave hits. This way you can identify and address potential problems before you really need your unit operating. During the summer, periodically check that the filter in your air conditioner is clean - Disposable filters should be replaced every one or two months – this will also help it run efficiently.

Question 5: How much would an electric car (since I have to charge it at my home) increase my electricity bill?

When electric vehicles start to become more available in the marketplace, they will be treated just like any other appliance in your home, so all standard Time-of-Use (TOU) billing rates will apply.  That means the best time to charge your plug-in vehicle would be over night, at off-peak times, to reduce the impact on your electricity bill.  The specific cost per charge or to ‘fill up’ (i.e. energize battery pack) is highly dependent upon the battery pack in the engine of the car, and other variances between makes and models of different manufacturers.  A small sedan would likely draw the following from the grid: Volt: 16kWh battery pack x $0.15 per kWh = ~$2.40 per charge**   It's important to keep in mind that currently information on the vehicles is limited so these costs are estimates only.

$0.10 TOU rate + $0.0105 transmission + $0.01352 distribution + $0.007 debt per kWh etc ~ $0.15 per kWh
- monthly customer charge not considered