This document discusses the role of energy storage in smart energy systems. It begins by defining smart energy systems as an approach that combines and coordinates smart electricity, thermal, and gas grids to identify synergies between sectors to achieve optimal solutions. Energy storage plays a key role in integrating renewable energy sources. Different types of energy storage are compared, including pump hydro storage, natural gas storage, oil tanks, and thermal storage. Power-to-heat, power-to-transport, and power-to-gas/liquid fuels are identified as important technologies to balance renewable energy sources hourly through various storage methods. The overall goal is a least-cost, 100% renewable energy system modeled hourly using tools like EnergyPLAN to analyze synergies between smart

1. The role of Storage
in Smart Energy Systems
Henrik Lund
Professor in Energy Planning
Aalborg University
ICARB Workshop: Energy Storage for the Built Environment
21 October 2014, ECCI, Edinburg, Scottland

2. Renewable Energy Systems
A Smart Energy Systems Approach to the
Choice and Modeling of 100% Renewable Solutions
1. Edition in 2010
2. Edition in 2014
New Chapter on
Smart Energy
Systems and
Infrastructures

3. The long-term Objective of
Danish Energy Policy
Expressed by former Prime
Minister Anders Fogh
Rasmussen in his opening
speech to the Parliament in
2006 and in several political
agreements since then:
To convert to 100%
Renewable Energy
Prime minister 16 November 2008:
”We will free Denmark totally from
fossil fuels like oil, coal and gas”
Prime minister 16 November 2008:
”… position Denmark in the heart
of green growth”

4. 100% Renewable Energy 2050
…… but how…???!!

5. Smart Energy Systems
The key to cost-efficient 100% Renewable Energy
• A sole focus on renewable electricity
(smart grid) production leads to electricity
storage and flexible demand solutions!
• Looking at renewable electricity as a part
smart energy systems including heating,
industry, gas and transportation opens for
cheaper and better solutions…
Power-to-Heat
Power-to-Gas
Power-to-Transport

6. Energy Storage
Pump Hydro Storage
175 €/kWh
(Source: Electricity Energy Storage
Technology Options: A White Paper
Primer on Applications, Costs, and
Benefits. Electric Power Research
Institute, 2010)
Natural Gas Underground Storage
0.05 €/kWh
(Source: Current State Of and Issues
Concerning Underground Natural Gas
Storage. Federal Energy Regulatory
Commission, 2004)
Oil Tank
0.02 €/kWh
(Source: Dahl KH, Oil
tanking Copenhagen A/S,
2013: Oil Storage Tank.
2013)
Thermal Storage
1-4 €/kWh
(Source: Danish Technology
Catalogue, 2012)

7. 100% Renewable Energy 2050
Power-to-Heat

8. Four different technologies
Power
Station
40 units of electrcity
80
Elec.
Electric
heating
80 units of
heat
300 units of
fuel
Electric heating
Power
Station
40 units of electricity
Boiler 80 units of heat
100 units of
fuel
Traditional System
100 units of
fuel
200
units of
fuel
CHP
plant
40 units of electricity
80 units of heat
135 units of
fuel
CHP System
CHP
unit
40 units of electricity
Heat
Pump
80 units of
heat
Integrated System with renewable energy
85 units of
fuel
Wind
turbine
20 elec.
10 elec.
45 heat

9. Domestic heating

12. Heat Roadmap Europe

13. 100% Renewable Energy 2050
Wind integration….!!

14. Danish
electricity
production
Big power
stations
Small CHP
plants
Wind
turbines

15. Backside of the medal
0
20
40
60
80
100
120
0 24 48 72 96 120 144 168 192 216 240 264 288 312 336
Hour
%

16. Wind energy
Input:
• Data from total productions
of wind turbines in the TSO
Eltra area (West Denmark).
Wind production Eltra 1996 (2042 MWh pr MW)
0
100
200
300
400
500
0 1098 2196 3294 4392 5490 6588 7686 8784
Hours
MWh/h
Wind production Eltra 2000 (2083 MWh pr MW)
0
500
1000
1500
2000
0 1098 2196 3294 4392 5490 6588 7686 8784
Hours
MWh/h
Wind production Eltra 2001 (1964 MWh pr MW)
0
500
1000
1500
2000
0 1098 2196 3294 4392 5490 6588 7686 8784
Hours
MWh/h

17. Energi System Analyse Model
CHP
Boiler
Electro-
lyser
Heat
pump and
electric
boiler
PP
RES
electricity
Fuel
RES heat
Hydro water
Hydro
storage
Hydro
power plant
H2 storage
Electricity
storage
system
Import/
Export
fixed and
variable
Electricity
demand
Cooling
device
Cooling
demand
Transport
demand
Process
heat
demand
Industry
Cars
Heat
storage
Heat
demand
www.EnergyPLAN.eu

18. A palette of solutions
• Flexible consumption
• Electricity storage
• CAES systems
• Regulation of CHP plants
• Electric heating
• Heat pumps
• Electric cars
• Stopping of wind turbines
• Production of hydrogen
• Transmission abroad
• V2G

19. Conclusions:
• Regulation of CHP and heat storage
(implemented in DK in 2004): Makes possible to
integrate 20% Wind Power (and 50% CHP)
• Adding large heat pumps and heat storage
capacity to existing CHP plants: Makes possible
to integrate 40% Wind Power (and 50% CHP)
• Electricity for transportation (integrate approx.
60% wind power)
• Important to involve the new flexible technologies
in the grid stabilisation task

20. 100% Renewable Energy 2050
… the overall system..

21. IDA Energiplan 2030

23. 100% Renewable Energy in
2050
Primær energiforsyning 100% VE i år 2050, PJ
0
100
200
300
400
500
600
700
800
900
1,000
Ref 2030 IDA 2030 IDA 2050 Bio IDA 2050 Vind IDA 2050
Eksport
VE-el
Solvarme
Biomasse
Naturgas
Olie
Kul
Biomass potentials and consumtion in IDA 2030, PJ
0
50
100
150
200
250
300
350
400
DEA potential IDA 2030 Max potential
Waste
Energy crops
Slurry fibre fraction
Slurry biogas
Wood
Straw

24. CEESA Project 2011/2012

25. TransportPLAN
modeling and
profiling in CEESA
• Particular focus due
to large challenges:
– >95% reliant on oil
– High increase
historically
– Large potential for
electric cars and
direct electricity
but..
– Specific challenges
in bringing in
electricity in sea,
aviation and good
transport

26. CEESA Project 2011/2012
Transport:
Electric vehicles is best from an energy
efficient point of view. But gas and/or liquid
fuels is needed to transform to 100%.
Biomass:
.. is a limited resource and can not satisfy
all the transportation needs.
Consequence
… Electricity from Wind (and similar
resources) needs to be converted to gas and
liquied fuels in the long-term perspective…

27. 100% Renewable Energy 2050
Power-to-Transportation

28. Electricity
(111 PJ)
Conversion Process││ │ │Transport Fuel
Electric Grid1
Electricity
(100 PJ)
│Transport Demand
294 Gpkm
323 Gtkm
OR
Resource
Resource
Electricity
(111 PJ)
Conversion Process││ │ │
Electricity
(100 PJ)
│ Transport Demand
313 Gpkm
Freight is not
applicable
Transport Fuel
ORElectric Grid1
Electrolyser1
Biomass
[Cellulose]
(65 PJ)
Electricity
(83.5 PJ)
Methane
(100 PJ2
)
H2
(60.5 PJ)
Steam
Gasifier
Chemical
Synthesis
Hydrogenation
1.9 Mt
Syngas
Resource Conversion Process││ │ ││ Transport Demand
61 Gpkm
36 Gtkm
Transport Fuel
OR
H2
O
(2.6 Mt)
4.5Mt
Marginal Heat
3
(7.6 PJ)
Power Plant
6 PJ
3
0.6 PJ
83 PJ
59 PJ
Electrolyser1
Biomass
[Glucose]
(60 PJ)
Electricity
(83 PJ)
Methane
(100 PJ2
)
H2
(60.5 PJ)
Anaerobic
Digester
Chemical
Synthesis
CO2
Hydrogenation
4.5 Mt
Resource Conversion Process││ │ ││ Transport Demand
61 Gpkm
36 Gtkm
Transport Fuel
OR
H2
O
(2.3 Mt)
Biogas
(50 GJ)
2.3 Mt
OR
Biomass1
(77 PJ)
Methanol/DME
(100 PJ5
)
Electricity
(178 PJ)
CO2
(7 Mt)
Co-electrolysis4
Carbon
Sequestration &
Recycling3Electricity2
(7.3 PJ)
Chemical
Synthesis
Syngas
(139 PJ)
H2
O
(5.7 Mt)
Resource Conversion Process││ │ ││ Transport Demand
or
50 Gtkm
83 Gpkm
Transport Fuel
Electricity
HeatPower Plant
Electrolyser6
Chemical
Synthesis
Fermenter
Hydrogenation
Chemical
Synthesis
Electricity
(307 PJ)
H2
(149.4 PJ)
Straw
(401.7 PJ)
H2
(72.2 PJ)
Methanol/DME
(62.6 PJ2
)
Ethanol
(100 PJ)
Methanol/DME
(337.5 PJ2
)
CO2
(4.4 Mt)
H2O
(15.5 Mt)
Hydrogenation
Low & High
Temperature
Gasification7
Resource Conversion Process││ │ │Transport Fuel
OR
Transport Demand │
52 Gpkm
67 Gpkm
31 Gtkm
39 Gtkm4
279 Gpkm
169 Gtkm
OR
OR
Lignin (197.7 PJ)
C5 Sugars (92.8 PJ)
Biomass
(40.2 PJ)
Power Plant
115
Mt
1 Mt
Marginal Heat1
(50.2 PJ)
303.6 PJ
3.4 PJ3
3.5 Mt

29. Smart Energy Systems
The key to cost-efficient 100% Renewable Energy
• A sole focus on renewable electricity
(smart grid) production leads to electricity
storage and flexible demand solutions!
• Looking at renewable electricity as a part
smart energy systems including heating,
industry, gas and transportation opens for
cheaper and better solutions…
Power-to-Heat
Power-to-Gas
Power-to-Transport

30. Smart Grid (2005)
No definition.
However it can be understood
from the context that a smart grid
is a power network using modern
computer and communication
technology to achieve a network
which can better deal with
potential failures.

31. Smart Grid - definitions
“A smart grid is an electricity grid that uses information and communications
technology to gather and act on information, such as information about the
behaviors of suppliers and consumers, in an automated fashion to improve the
efficiency, reliability, economics, and sustainability of the production and
distribution of electricity.” (U.S. Department of Energy)
“Smart Grids … concerns an electricity network that can intelligently integrate
the actions of all users connected to it - generators, consumers and those that
do both - in order to efficiently deliver sustainable, economic and secure
electricity supplies.” (SmartGrids European Technology Platform, 2006).
“A Smart Grid is an electricity network that can cost efficiently integrate the
behaviour and actions of all users connected to it – generators, consumers and
those that do both – in order to ensure economically efficient, sustainable
power system with low losses and high levels of quality and security of supply
and safety.” (European Commission, 2011)
“Smart grids are networks that monitor and manage the transport of electricity
from all generation sources to meet the varying electricity demands of end
users” …. “The widespread deployment of smart grids is crucial to achieving a
more secure and sustainable energy future.” (International Energy Agency
2013).

32. Smart heating and
cooling grids
• In the European Commission’s strategy
[7] for a competitive, sustainable and
secure “Energy 2020“, the need for “high
efficiency cogeneration, district heating
and cooling” is highlighted (page 8). The
paper launches projects to promote,
among others, “smart electricity grids”
along with “smart heating and cooling
grids” (page 16).

33. Smart Energy Systems
• Smart Electricity Grids are define as electricity infrastructures that can
intelligently integrate the actions of all users connected to it - generators,
consumers and those that do both - in order to efficiently deliver sustainable,
economic and secure electricity supplies.
• Smart Thermal Grids (District Heating and Cooling) is a network of pipes
connecting the buildings in a neighbourhood, town centre or whole city, so that
they can be served from a centralised plant as well as from a number of
distributed heat and/or cooling producing units including individual contributions
from the connected buildings.
• Gas Smart Grids are defined as gas infrastructures that can intelligent integrate
the actions of all users connected to it - supplies, consumers and those that do
both - in order to efficiently deliver sustainable, economic and secure gas
supplies and storage.
Smart Energy Systems is define as an approach in which Smart
Electricity, Thermal and Gas Grids are combined and coordinated to
identify synergies between them in order to achieve an optimal solution
for each individual sector as well as for the overall energy system.

34. Energi System Analyse Model
CHP
Boiler
Electro-
lyser
Heat
pump and
electric
boiler
PP
RES
electricity
Fuel
RES heat
Hydro water
Hydro
storage
Hydro
power plant
H2 storage
Electricity
storage
system
Import/
Export
fixed and
variable
Electricity
demand
Cooling
device
Cooling
demand
Transport
demand
Process
heat
demand
Industry
Cars
Heat
storage
Heat
demand
www.EnergyPLAN.eu

35. Smart Energy Systems:
Hourly modelling of all smart
grids to identify synergies!
… and influence of different
types of energy storage..!

36. CEESA Project 2011/2012
Smart Energy Systems:
Integrated use of Power-To-Heat, Power-
To-Transport and Power-To-Gas/Liquid fuel
RES integration:
Hourly balance of wind etc. by use of
thermal and gas/fuel storage. (Least-cost
solution)
No electricity storage
… except from batteries in cars…

37. Energy Storage
Pump Hydro Storage
175 €/kWh
(Source: Electricity Energy Storage
Technology Options: A White Paper
Primer on Applications, Costs, and
Benefits. Electric Power Research
Institute, 2010)
Natural Gas Underground Storage
0.05 €/kWh
(Source: Current State Of and Issues
Concerning Underground Natural Gas
Storage. Federal Energy Regulatory
Commission, 2004)
Oil Tank
0.02 €/kWh
(Source: Dahl KH, Oil
tanking Copenhagen A/S,
2013: Oil Storage Tank.
2013)
Thermal Storage
1-4 €/kWh
(Source: Danish Technology
Catalogue, 2012)

38. More information:
• http://www.emd.dk/desire/skagen
• http://www.emd.dk/el
http://energy.plan.aau.dk/book.php
www.EnergyPLAN.eu www.heatroadmap.eu
www.4DH.dk