IEEE Power & Energy Magazine - January/February 2017 - 33

06:30 p.m.

06:00 p.m.

05:30 p.m.

05:00 p.m.

04:30 p.m.

Energy
Rush Hour

04:00 p.m.

03:30 p.m.

03:00 p.m.

02:30 p.m.

02:00 p.m.

01:30 p.m.

Fraction of Total Load

Precooling
1.0
0.8
0.6
0.4
0.2
0.0

versity acknowledges support from the National Natural Science
Foundation of China (51620105007). S. Heinen acknowledges
support from the Fonds National de la Recherche, Luxembourg
(project reference 6018454) and CITIES (DSF 1305-00027B/
DSF). J. Kiviluoma acknowledges support from the FLEX-e
program funded by TEKES.

Time
Actual ac Use
Projected ac Use Without Rush-Hour Rewards

figure 9. Employing heat flexibility in residential buildings
to avoid electricity demand when the electricity grid faces
high loads. (Source: nest.com.)

increased flexibility. MPC is applied by companies such as
BuildingIQ or QCoefficient when they exploit chiller efficiency
variations due to ambient temperature to achieve energy savings without overly affecting occupant comfort. An example of
smart-thermostat-based control is shown in Figure 9, where the
smart thermostat Nest performed large-scale peak shaving by
precooling American residential buildings.
In 2011, China initiated a series of pilot projects that
substitute electric boilers to for coal-fuelled CHP boilers
in the Jilin province. The electric boilers often use surplus
wind generation as their energy source. From 2015, the
project has expanded to all the northern provinces such as
Hebei, Liaoning, Inner Mongolia, and Xinjiang. The electric boilers are equipped with water tanks capable of providing 10~15 hours of storage.

Conclusions
Heating and cooling offer considerable flexibility potential
for power systems. Much of this could become cost-effective
as the share of variable and uncertain generation increases.
Simultaneously, electrification of heating offers a possibility
for heat sector decarbonization. However, the picture is not
entirely rosy. Seasonality in space-heating needs makes it a
less attractive source of flexibility. On the other hand, flexibility from heating could be partially complemented by flexibility from cooling or from more stable loads in the industrial
sector. At the same time, the industrial sector is very diverse
and will require elaborate research to understand the true
flexibility potential in heat-consuming industrial processes.

Acknowledgments
H. Madsen acknowledges support by CITIES (Center for ITIntelligent Energy Systems, DSF 1305-00027B). G. Strbac
acknowledges support from the U.K. Research Council-funded
project "Energy Storage for Low-Carbon Grids." Tsinghua Unijanuary/february 2017

For Further Reading
D. Patteeuw, K. Bruninx, A. Arteconi, E. Delarue, W.
D'haeseleer, and L Helsen, "Integrated modeling of active
demand response with electric heating systems coupled to
thermal energy storage systems," Appl. Energy, vol. 151,
pp. 306-319, Aug. 2015.
S. Heinen, D. Burke, and M. O'Malley, "Electricity, gas,
heat integration via residential hybrid heating technologies:
An investment model assessment," Energy, vol. 109, pp.
906-919, Aug. 2016.
K. MacLean R. Sansom, T. Watson, and R. Gross, "Comparing the impacts and costs of transitions in heat infrastructure," Centre for Energy Policy and Technology, Imperial
College, London, U.K., Apr. 2016.
J. Kiviluoma, "Managing wind power variability and uncertainty through increased power system flexibility," Ph.D.
dissertation, Aalto Univ., Dept. Applied Physics, VTT Sci 35,
Espoo, Finland, 2013, p. 77.
T. Naegler, S. Simon, M. Klein, and H. C. Gils, "Quantification
of the European industrial heat demand by branch and temperature level," Int. J. Energy Res., vol. 39, pp. 2019-2030, Oct. 2015.
N. Zhang, X. Lu, C. P. Nielsen, M. B. McElroy, X. Chen,
Y. Deng, and C. Kang. "Reducing curtailment of wind electricity in China by employing electric boilers for heat and pumped
hydro for energy storage," Appl. Energy, vol. 184, pp. 987-994,
Dec. 2016.
P. Bacher, H. Madsen, H. A. Nielsen, and B. Perers, "Shortterm heat load forecasting for single family houses," Energy
Buildings, vol. 65, pp. 101-112, Oct. 2013.

Biographies
Juha Kiviluoma is with the VTT Technical Research Centre, Espoo, Finland.
Steve Heinen is with University College Dublin, United
Kingdom.
Hassan Qazi is with University College Dublin, United
Kingdom.
Henrik Madsen is with the Danish Technical University,
Lyngby, Denmark.
Goran Strbac is with Imperial College London, United
Kingdom.
Chongqing Kang is with Tsinghua University, China.
Ning Zhang is with Tsinghua University, China.
Dieter Patteeuw is with Katholieke Universiteit Leuven,
Belgium.
Tobias Naegler is with the German Aerospace Center,
Stuttgart.
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