Chasing the Peak

McMaster is amongst the largest electricity consumers in Ontario.  This initiative is to reduce our electricity peak demand during provincial peak demand hours, similar to initiatives being taken all across the province by large electricity consumers including universities and colleges, such as University of Ottawa and Western University.

The Province of Ontario encourages electricity consumers to help reduce their peak electricity demand to avoid additional generation sources and associated greenhouse gases (GHGs). The university monitors the provincial electricity forecasts available at  In addition university staff monitor weather forecasts from other sources to determine the likelihood of a peak hour. The ratio of McMaster’s energy usage to that of Ontario on the top 5 peak hours of the year is used to calculate the following year global adjustment charges.

See below for annual results of savings and impacts brought on by the Chasing the Peak Initiative, and a list of frequently asked questions regarding what Chasing the Peak is, and what to do on a Peak Day.

Past Results

2016 Results

2015 Results

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Chasing the Peak FAQ

General Inquiries

What is a Peak Day?
Large amounts of electricity cannot be stored and has to be generated in real time according to consumer demand.  Electricity consumer demand varies based on time of day and weather.  Typically electricity demand is highest during summer afternoons.  To meet this demand of a few hours, generation sources are required to be able to respond in real time basis, at significant capital (construction), operating and environmental costs and emissions. 
The Province of Ontario encourages electricity consumers to help reduce this peak electricity demand to avoid additional generation sources. 
A total of 10-15 peak days are expected in a year during which McMaster tries to reduce its electricity demand over a period of 3-4 hours/day.

How does the university know it’s a peak day?
The university monitors the provincial electricity forecasts available at .  In addition university staff monitor weather developments and forecasts from other market sources to determine the likelihood of a peak day. 
With major electricity consumers participating in the initiative, the market response can result in shifting of the electricity peak towards later in the evening.  Hence “Chasing the Peak”. 

Can you advise me in advance of a Peak event?
The university endeavors to give as much advance notice as possible for each event, however with the electricity real time market forecasts notice is only available 6 – 18 hours before an event.

When does the peak occur?
The peak can occur anywhere in the 4 hour block that is communicated to the campus.

    • Non critical supply fans (excluding critical areas, labs, IT server rooms) are shut down anywhere from 1 to 2 hours within the 4 hour block.  
    • The campus central cooling equipment is scheduled to run full throttle prior to the peak hours to provide a pre cooling effect.  The cooling equipment is shut down for 2-4 hours during the 4 hours block. 
    • In order to minimize the campus impact from last year, the campus chilled water pumps are kept on through out the event to provide a lower level of cooling effect during the peak events.  The campus chilled water loop cools lab equipment, fridges / freezers and server rooms.
    • University staff monitor the real time electricity market and bring the cooling equipment back as the peak provincial hour is over.

When should I expect a peak day?
Peak days usually occur during the end of June, July, August and beginning of September. Depending on the summer the peak days may occur during the winter.



Lab Related Questions

How will Lab space be affected?
Labs are considered critical areas therefore the fans are on bringing in fresh air however, there is no air conditioning.  If there is a high volume of people in the lab space we suggest minimizing activities as much as possible  
Fume hoods will be functional nevertheless we suggest that you minimize usage as much as possible during this time. 

Can I use my fume hood?
Yes, you can still use your fume hood.  Fans will be on and bring in fresh air.  We recommend avoiding the usage of fume hoods. 

How does this effect experiments?
Experiments can still continue, although the room temperature may rise as equipment contributes to heat load.  Temperature sensitive work may require additional monitoring. Ensure chemicals are properly stored.

Will my lights or equipment be shut down?

Facilities Services will not be shutting off any essential lighting or lab equipment. We do ask for assistance that any non essential lights or equipment that is not being used be shutoff, it is a good practice to keep non essential systems off unless needed.


Lecture Theaters/ Classrooms/ Tutorials

How will lecture halls/classrooms be affected?
You may notice an increase in temperature due to the supply fans being shut down. Due to the high occupancy of these rooms they are the first to be cooled after the peak occurs. If the Lecture Theater or classroom is at an uncomfortable temperature please relocate if possible.  (how do we tell them to move)

Should we be cancelling classes/tutorials?
No. The fan will only be shut off for up to 2 hours  - facility services works hard  to get all the classrooms and lecture theatres back on.

Up to what temperature is it safe to keep students/TAs/staff in lecture/lab/tutorial for summer courses?

There is no legal upper limit for temperature under the Ontario Occupational Health and Safety Act.  The University does follow Risk Management Manual # 408, Heat Stress Prevention Program.  Under extreme heat conditions the program provides a Heat Response Plan to be followed.  During hot conditions it is important to remain hydrated at all times, to limit activity levels if possible and to take cool breaks when necessary.  Consideration may be given to relocating to a cooler location on campus, that provides more comfort if available.  Certain activities should be evaluated for appropriateness during these conditions, i.e. use of heat generating equipment, physically demanding or labour intensive work, etc.  It is important to remember that Chasing The Peak is intended for a short period of time.


Building Specific Active Fans

*The highlighted section indicates the supply fans are still ACTIVE. There will still be no cooling but the fans will maintain airflow through fumehoods and labs.

A.N. Bournes Science Building

Burke Science Building

General Science Building

John Hodgins Engineering Building

Nuclear Research Building

Engineering Technology Building

LSB entire building stays on

MDCL entire 2nd, 4th and 5th floors remain on

IWC entire spinal chord research wing remains on, rest of the building is off  (this is indicated in the chasing the peak notice anyways)

PS labs

Alvin A. Lee Museum of Art entire gallery not affected

Mills Library special collections


Please email with your queries, complaints and feedback.  Any suggestions to improve the initiative are welcome.

Other Universities: