Coping with Time of Day Electricity Charges

Ontario Hydro has recently introduced time of use metering for residential electric power. Under the new billing scheme, usage is divided into three periods — on-peak, mid-peak and off-peak — on-peak and mid-peak switch places winter and summer. With delivery charges, debt retirement charges (probably Ontario Hydro partying charges) and the new and improved ‘Harmonized Sales Tax’ representing roughly 55% of the bill the new charge structure is a stiff increase in utility costs.

Over the last few years we have averaged around 0.14/kw-hr , with the new structure our average is just under 0.17/kw-hr. I suspect that many people will see a much larger jump — here a lot of work has been put into understanding where we used power and allowing us to monitor usage on an ongoing basis. (It may have helped that back in the 70s I went through an extensive program on industrial energy auditing.)  And a few changes have been made to help manage when power was being used. This information might be helpful to others seeking to do the same thing.

Living in a rural area we use electricity for water pumping and treatment — a cost not shared by city dwellers. Otherwise we are pretty typical — other than our local computer network and redundant internet connections. As we had considered adding alternate energy sources to offset our power costs I had done a detailed energy audit — basicly a list of every electricity-using device in the place cataloging when it was run and (if possible) how much power it actually used. I purchased a ‘Killawatt’ power meter that plugs between the appliance and the wall — this allowed me to measure actual usage over an extended period for 110v devices. I also bought and installed a whole house power monitor that provides second by second usage and line voltage information and logs it on a computer.

What we learned is that some appliances used far more than we expected — the ‘energuide’ stickers were just wishful thinking. The old refrigerator went quickly when we realized what a pig it was. Over a couple of years the savings in utility costs paid for the new one and we are almost used to the funny noises it makes. And almost all of our lights are compact florescent or LED. One surprise was the standby electricity usage for our A-V entertainment equipment. In ‘standby’ the total draw was on the order of 120 watts – $16/month at our current rates. Everything was plugged into a power bar so adding a remote switch made it convenient to toggle everything off untill we want to use it.

Another change was testing how long we could draw hot water from our electric water tank with the power off. We had added an extra insulating blanket on principle so knew it stayed hot for a long time. The whole house meter showed that the heater kicked on roughly every 30 minutes — generally not on for a long time but it added up. With the power off we could go all day without significant cooling. So I put a heavy duty timer on the power feed that turns it off between 7am and 9pm.

We had already put computerized thermostats on our electric baseboards and added an air-sourced heat pump for the bulk of our winter heat and cooling. With less than 24 inches of topsoil the rock drilling costs of a ground sourced heat pump would have put payback into the 20+ years of an alternate energy (in your dreams) project. Cost savings for the heat pump over baseboards had a 5 year payback. And with no ductwork in the house our realistic choices were very limited. Adding insulation and sealing air leaks also helped a lot — and this was all before the spectre of TOU metering reared its head.

And we looked real hard at all the computer gear that was left running and decided to turn roughly half of it off, except on weekends when the off-peak rates are in effect all the time. Probably just as well, spend too much time at the thing anyhow.

The other big thing was deciding to schedule activities where possible to use the cheap rates. House cleaning is a weekend activity, as is baking and laundry. The dishwasher is run at bedtime. And the drier is rarely used — a new laundry line gets a real workout when the sun is up. But we use the microwave as needed and do other activities at reasonable times — like using the table saw to cut material for projects.

Overall, between awareness and proactive changes we have been able to shift our usage so that between 65% and 70% is in the off-peak rates. And our continuous power draw for water system, refrigerator, freezer and assorted appliances dropped from 1.25kw/hr to 0.7kw/hr. As retirees on fixed incomes this is significant — were we working or still had children to care for it would probably have been much more difficult. But it can be done — but there is no substitute for trying to understand our usage habits and the demand patterns of our electricity-consuming devices. Then make changes and monitor the results. This is probably the only way to be successful in controlling utility costs.

One thought on “Coping with Time of Day Electricity Charges

  1. Sounds like you have pretty much everything covered in this plan! You mention being able to shift a lot to off peak times, overall through, from your changes, how much do you think you have cut out completely or saved? I am also curious which whole home monitor your purchased.

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