Earth Matters

Sunnybrook contributing to a more reliable & sustainable electricity grid for Ontario

You wouldn’t know it but this hospital is helping to keep the lights on.  For this new energy initiative – Sunnybrook’s most recent ‘Smart Energy Action’ – we’ve teamed up with ENBALA Power Networks to provide real-time Grid Balance or regulation service, to the Ontario electricity grid.  Sunnybrook is one of only a handful of customers currently participating in the leading edge smart grid program and the first in the healthcare sector.

What is Grid Balance:

Grid Balance, also known as regulation service,  helps to match Ontario’s total electricity generation with Ontario’s total electricity demand on a second by second basis, keeping it in balance.  Since electricity is not traditionally stored, it is very important that the amount of electricity generated in each moment correctly match the demand loads. If too much or too little electricity is produced, it can be harmful to the electricity grid and the users.  As we introduce more variability into our province’s power generation by connecting more solar and wind power (which are intermittent sources are power), keeping the grid in balance becomes more difficult and more important. Until now, this load matching service has been provided by generators.

Enbala power networks supply and demand

(Graphic showing the balance of supply and demand known as Grid Balance from ENBALA Power Networks)


The ENBALA GOFlex™ Platform:

ENBALA has been contracted by Ontario’s Independent Electricity System Operator (IESO) to provide Grid Balance through real-time, demand-side management. ENBALA has connected a network of large electricity consumers that have some flexibility in when and  how they use power.  Through the use of their innovative smart grid technology platform, GOFlex™, ENBALA can intelligently manage the flexibility of electricity loads in response to real-time needs of the electricity grid.  The result is a more reliable,  sustainable and often cheaper method of regulation service.  This is because the  GOFlex™ platform is able to respond within seconds to signals from the grid operator to adjust the power usage of participating businesses and institutions.

Check out this video from ENBALA’s website to learn about how Grid Balance works:


Group of people  Sunnybrook Tour

(On October 31st, Sunnybrook hosted the official launch of this new initiative alongside ENBALA, the IESO and the Ontario Ministry of Energy. Photo of the event speakers from left to right: Bruce Campbell – the President and CEO of the I.E.S.O, Ron Dizy – the President and CEO of ENBALA Power Networks, Michael Young – Sunnybrook’s Executive Vice President and Chief Administrative Officer, Bob Delaney – The Parliamentary Assistant to the Minister of Energy and MPP for Mississauga- Streetsville )


Sunnybrook Participation: 

At Sunnybrook, we have five large 1400 ton air conditioning chillers that are connected to the ENABALA’s Ontario Grid Balance Network. Each chiller uses up to 800 kw of power to produce cold water for cooling the campus and during the summer peak conditions the electricity load from these chillers make up 25% of our total electricity load.  There is flexibility in when and how we use the power for these machines because we can adjust the temperature of the cold water that is produced up and down by a couple of degrees while keeping hospital spaces within ordinary comfortable temperatures.

This is the next level of demand response. Traditional demand response would require an electricity customer to curtail (reduce) their energy use for hours at a time, which is not something that is easily achievable for a hospital. The type of demand response we are talking about here is real-time power draw adjustments for only short periods of time (usually less than 15 minutes). These power draw adjustments are fluctuating up and down for short time intervals to help constantly match the grid. This makes it easy for hospitals to participate because the total cooling capacity provided does not change and the total energy used over time also remains the same.


(photo of Sunnybrook staff posing in front of one of the five air-conditioning chillers participating in the program)


Benefits for Sunnybrook:

  • we are participating in a simple, automatic and cost free demand response program that leverages existing energy-consuming assets and makes them “dual-use”
  • we are contributing to the reliability of the province’s power system
  • we are contributing to the reduction of green house gas emissions for the province
  • we gain experience in new innovative technologies that can be applied elsewhere at Sunnybrook to achieve further benefits in the future
  • we are generating a new revenue stream that can be applied against energy initiatives and patient care

In today’s information age we have so much data available to help inform us how to manage our energy use. Taking part in the Ontario Grid Balance initiative is just one of the steps we are taking as part of our Smart Energy Actions Program, which we launched earlier this year to manage our energy use more intelligently.

About the author


Laura Berndt (Hough) is the Manager of Energy & Sustainability in Plant Operations at Sunnybrook.