This document analyzes the relationship between energy savings, peak load savings, and electric energy savings for new buildings in Toronto. It finds that while there is a weak correlation between total energy savings and peak demand savings, there is a strong positive correlation between electric energy savings and peak demand savings. Based on the analysis of 60 buildings, the largest opportunities for peak load savings are in space cooling and lighting, while the largest opportunities for electric energy savings are in lighting and ventilation. The document recommends that building codes be updated to specify required proportions of electric energy savings and to encourage passive design strategies like daylighting and natural ventilation to further reduce peak loads.

1. What is the relation between energy consumption
savings and peak load savings
and how can this affect future energy conservation requirements?
Dalia Bahy
PH.D, MRAIC, B.Eng, LEED AP BD+C
Consultant
under contract to the
City of Toronto
By
Nickolas Lysenko
P.Eng.
Senior Engineer
City of Toronto

2. Scope and limitations of the study
Methodology and data acquisition
The relationship between total energy savings, electric energy
savings and summer peak load savings
Summer peak load end-use and electric energy end-use
Energy efficiency requirements in building codes and standards
for new buildings in the City of Toronto
Conclusions and recommendations
CONTENTS

3. INTRODUCTION

4. INTRODUCTION
Peak electrical demand trends and pressures
associated with rapid growth
have increased concerns about electric system
reliability combined with concerns about the cost of
new generation and transmission and distribution.
Energy conservation is a first priority resource to
address both peak demand and energy needs
Recently, many of the green rating systems, codes
and standards have included some new
requirements to maximize efficiency in electricity
production and distribution and increase the
reliability of the power grid through requiring for
reduction in peak loads.

5. INTRODUCTION
This paper addresses number of questions:
What is the relationship between energy
consumption savings and peak load savings?
How far peak load savings can be achieved for
different building types?
What type of energy end-uses contribute most
to peak load?

6. SCOPE AND LIMITATIONS OF THE STUDY
The paper only focuses on peak load reduction and more specifically
on critical load peak reduction.
It is based on energy model reports for new construction projects in
the City of Toronto and it does not include information about existing
buildings.

7. METHODOLOGY AND DATA ACQUISITION
Analyses available data collected from the energy model reports of mid to
high-rise buildings that were submitted to the City of Toronto. A total of
60 buildings (1,782,263.6 m2 gross floor area) were assessed and a number
of observations were made from analyzing this data.
The study aggregated the end-use peak load and electric energy end-use
data for the various end-use purposes: lighting, space cooling, domestic
hot water, ventilation fans, pumps and other miscellaneous equipment.
The data was analyzed and the proportion of electric energy end-use and
summer peak load end-use was determined.

8. Finally existing energy codes and standards for new buildings in the
City of Toronto were discussed to identify how future energy
conservation requirements can provide relief for electric grid stresses
and improve infrastructure resiliency.
Methodology and data acquisition

9. THE RELATIONSHIP BETWEEN TOTAL ENERGY
SAVINGS, ELECTRIC ENERGY SAVINGS AND SUMMER
PEAK LOAD SAVINGS

10. -60%
-40%
-20%
0%
20%
40%
60%
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61
%Savings
Buildings
%Total energy savings % Electricity savings % Summer peak demand savings
Summer peak demand savings, total energy savings and electric energy savings
(All buildings)

11. THE RELATIONSHIP BETWEEN TOTAL ENERGY
SAVINGS, ELECTRIC ENERGY SAVINGS AND SUMMER
PEAK LOAD SAVINGS
No. of buildings
achieved
savings ≥ 25%
% of buildings
achieved
savings ≥ 25%
Summer Peak
load Savings
17 28%
Electric energy
savings
21 35%
Total number of buildings achieved peak load savings and electricity savings
above MNECB (All buildings)

12. y = 0.6489x - 0.0705
R² = 0.0925
-50%
-40%
-30%
-20%
-10%
0%
10%
20%
30%
40%
50%
60%
0% 10% 20% 30% 40% 50% 60%
%Summerpeakdemandsavings
% Total energy Savings
% Summer peak
demand savings
y = 0.8793x - 0.0037
R² = 0.7194
-50%
-40%
-30%
-20%
-10%
0%
10%
20%
30%
40%
50%
60%
-30% -20% -10% 0% 10% 20% 30% 40% 50% 60%
%Summerpeakdemandsavings
% Electric energy savings
% Summer peak
demand savings
Figure A
Summer peak demand savings relative to
total energy savings
Figure B
Summer peak demand savings relative to
electric energy savings

13. SUMMER PEAK LOAD END-USE AND ELECTRIC ENERGY
END-USE

14. Figure A
Summer Peak load End-use
Figure B
Electricical Energy End-Use
31%
13%
0%
40%
2% 14%
0% Lights
Misc. Equipment
Space Heating
Space cooling
Pumps
Vent Fans
Hot Water
RESIDENTIAL BUILDINGS SUMMER PEAK LOAD END-USE AND ELECTRIC ENERGY END-USE
30%
21%
3%
9%
2%
1%
34%
0%
Lights
Misc. Equipment
Space Heating
Space Cooling
Pumps & Misc
Vent Fans
Hot Water

15. A NUMBER OF OBSERVATIONS CAN BE TAKEN FROM THIS:
Cooling loads and lighting represent 71% of the summer peak load and
represent a great opportunity for improvement.
Ventilation fans and lighting represent 64% of the electric energy consumption
and also represent a great opportunity for improvements.

16. Figure A
Summer Peak load End-use
Figure B
Electricical Energy End-Use
COMMERCIAL BUILDINGS SUMMER PEAK LOAD END-USE AND ELECTRIC ENERGY END-USE
33%
6%
1%
35%
8%
17%
0%
Lights
Misc. Equipment
Space Heating
Space cooling
Pumps
Vent Fans
Hot Water
31%
23%
0%
13%
5%
27%
1%
Lights
Misc. Equipment
Space Heating
Space Cooling
Pumps
Vent Fans
Hot Water

17. FACTORS CONTRIBUTING TO SUMMER PEAK LOAD END-USE AND
ELECTRIC ENERGY END-USE TRENDS
Toronto have the most high-rise buildings under construction in North
America.(Tara ,2012)
MURBs in Toronto are designed by professionals who are typically requested to
only comply with minimum codes and standards.
Most of the buildings included large windows with high window wall area ratios
which allowed summer heat gains and did not benefit from daylight (John, 20 11)
Energy conservation requirements are defined in a way that can be achieved
without adherence to best sustainable building architectural practices (Edna,
2008).

18. FACTORS CONTRIBUTING TO SUMMER PEAK LOAD END-USE AND
ELECTRIC ENERGY END-USE TRENDS
Most of the new MURB's corridors, hall ways, collective spaces, parking
garages and amenities are artificially lit and ventilated. Also lighting and
ventilation fans are running through the entire day. Even in the residential
units itself, many spaces such as dens, bathrooms, kitchens and corridors are
completely artificially lit or ventilated.
When buildings are designed and constructed, energy efficiency is one
concern amid many other concerns that may be given higher priority by
architects. These can be structural or fire safety, room size, and even the
view from the windows. Energy efficiency in buildings may hence be low
on the list of requirements (International Energy Agency, 2008).

19. ENERGY EFFICIENCY REQUIREMENTS IN BUILDING
CODES AND STANDARDS FOR NEW BUILDINGS IN THE
CITY OF TORONTO

20. Energy efficiency requirements in building codes and
standards for new buildings in the City of Toronto
The OBC energy efficiency requirements can either be
fulfilled by meeting a number of requirements (prescriptive
rules) or by a calculation based on a comparison with fixed
values and the fulfilment of the prescriptive rules (energy
model building or a trade of model).

21. Energy efficiency requirements in building codes and
standards for new buildings in the City of Toronto
In an effort to encourage energy efficiency further in the City of Toronto, the TGS
raised the energy efficiency targets from 1st January 2014 to 15% over the OBC (City
of Toronto, 2014).
The current OBC and the TGS require a percentage of improvement above a
reference code but does not include additional qualifier that specify the electric
energy savings proportion of the total savings required.
The current OBC includes requirements for Building Envelope, HVAC systems,
Service Water Heating, Power, Lightning, electric power systems and motors but
does not include any specific requirements that address passive cooling, or natural
ventilation or any other passive elements.

22. Energy efficiency requirements in building codes and
standards for new buildings in the City of Toronto
The current OBC also includes additional requirements to address peak loads. The
requirements focus on cooling equipment, fan power limitations for cooling and
ventilation systems, and interior lighting power density (Ministry of Municipal
Affairs and Housing, 2012). However, the current OBCdoes not include any
requirements that could improve the architectural designs and yield substantial
peak reduction.

23. CONCLUSIONS AND RECOMMENDATIONS

24. CONCLUSIONS AND RECOMMENDATIONS
In consideration of this paper's findings, a number of recommendations are
presented as follow:
There is weak correlation between total energy savings and peak demand savings
among the buildings analyzed while there is a strong positive correlation between
electric energy savings and peak demand savings.
The current OBC and the TGS requires a percentage of improvements above a
reference code but does not include additional qualifiers that specify the electric
energy savings proportion of the total savings required. Going forward, and to use
energy conservation as a resource to address electric grid stress issues, it is
recommended to specify additional qualifiers that state the proportion of electric
energy savings required.
According to what the data in this paper has suggested, the largest potential for
peak load savings in Toronto is space cooling and lighting while the largest potential
for electric energy savings in Toronto is lighting and ventilation.

25. CONCLUSIONS AND RECOMMENDATIONS
Passive cooling, daylighting and natural ventilation have the potential to reduce
substantially mechanical system and artificial lighting demand, if appropriate,
architectural design especially fenestration and sun shading strategies are employed
(International Energy Agency, 2008).
It would be useful if the current energy efficiency regulations included additional
sub-optimization requirements for passive heating /cooling, natural ventilation and
daylighting.
The current energy conservation requirements do not require adherence to best
practices in sustainable building architectural design. It is recommended to provide
guidelines that address and encourage passive solutions especially the ones that
can yield substantial peak reductions.

26. THANK YOU