can we achieve 100% renewables? flexibility options in the electricity system

Dr. G. Papaefthymiou

22/05/2014

Can we achieve 100% renewables? Flexibility options in the electricity system

Webinar Leonardo Energy

© ECOFYS | |

Overview

1. Definition of power system flexibility

2. Need for Flexibility

3. Overview of Flexibility Options

4. Mapping of Flexibility Options

5. Conclusions and recommendations

22/05/2014 Dr. G. Papaefthymiou

© ECOFYS | | © ECOFYS | |

The key physical components of flexibility:

22/05/2014

Demand

Supply

Network

System

System

Demand: partly controllable

Network: ability for spatial matching

System: operational rules

Supply: controllable or intermittent (VRES*)


> Power systems are designed to ensure a spatial and temporal

balancing of generation and consumption at all times.

*VRES: Variable Renewable Energy Sources


Definition of Power System Flexibility

> Power system flexibility represents the extent to which a power

system can adapt electricity generation and consumption as needed to

maintain system stability in a cost-effective manner.

> Flexibility is the ability of a power system to maintain continuous

service in the face of rapid and large swings in supply or demand.

> Measures of flexibility:

– Ramp rates, minimum up/down times, and start-up/shut-down

times are commonly used indicators of flexibility, measured as MW

available for ramping up and down over time

> Role of power networks:

– Key enablers of flexibility, since they define the spatial dimension

of balancing and thus to which extent flexibility resources can be

shared between adjacent areas.



Overview








Daily patterns of net electricity demand for

different VRES penetration levels

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-20

0

20

40

60

80

Syst

em N

et D

eman

d (

GW

)

No RES 20% 40% 60% 80%

Hours



Hourly ramping range of net electricity demand

for different VRES penetration levels


-25

-20

-15

-10

-5

0

5

10

15

20

25

Syst

em N

et D

eman

d H

ou

rly

Ram

ps

(GW

/h)

No RES 20% 40% 60% 80%

Hours

© ECOFYS | | © ECOFYS | | 22/05/2014

-40

-20

0

20

40

60

80

100

120

140

160

180

200

-20

0

20

40

60

80

100

Spo

t p

rice

[€

/MW

h]

Ge

ne

rati

on

/ D

em

and

[G

W]

Kernenergie Braunkohle Kohle Erdgas

Öl Andere Pumpspeicher Laufwasser

Saisonspeicher Wind Solar Unbekannt

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

Nuclear Lignite

Oil

Hydro storage

Other

Natural Gas

Pump storage

unknown

Run of River

Export

Wholesale

price

Coal

Demand

Oversupply events already happen

Oversupply event:

High RES

Low Demand

CGs at their limit

Source: EEX, ENTSO-E,

the example shows

German ex-post data

for one week in

February 2011



Dynamic range of net electricity demand for

different VRES penetration levels

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-60

-40

-20

0

20

40

60

80

Syst

em N

et D

eman

d (

GW

)

No RES 20% 40% 60% 80%

Hours

BASELOAD

MIDLOAD

PEAK LOAD



Need for flexibility

> Traditional power systems:

Need for flexibility because of demand variations and sudden loss

of generation units

– variability of demand

– uncertainty of supply

• Flexibility provided by supply side (power plant fleet)

> Introduction of variable RES:

– Increasing the need for flexibility: Increase in variability

and uncertainty in the supply side

– Reduction of the flexibility potential: VRES displace part

of the conventional generation capacity (impact on portfolios

and operational)

• New flexibility options are needed



Impacts of VRES on the flexibility timeline

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Long term planning

flexibility

Does my system have sufficient

resources to manage

operational variability?

Operational planning

flexibility:

How many flexibility resources

should be committed to ensure

secure operation?

Operational

Flexibility:

Which are the

most

economic

resources?


Source: H. Holttinen, A. Tuohy, M. Milligan, E. Lannoye, V. Silva, S. Muller, L. Soder, The flexibility workout: Managing variable resources and assessing the need for power system mod-ification, IEEE Power & Energy Magazine, November/December 2013


Overview








Categorisation of flexibility options

System

Energy Storage

Supply

Net-work

Demand



Overview of flexibility options

22/05/2014

Supply

Demand

Energy Storage

System

Net-work

1. Flex Coal, 2. Gas

3. Oil, 4. Biogas,

5. CHP, 6. Nuclear

7. VRES

8. Pump storage,

9. (AA-)CAES

10. Flywheels

11. Batteries

12 Hydrogen (Power to Gas)

13. Demand Response

- Energy intensive industries

- Services

- Smart applications

14. Electric vehicles

15. Heat pumps

16. Resistance heating

17. Network expansion (Installation of lines)

- Add transmission capacity (HVAC /HVDC)

- Increase meshing, alleviate congestions

18. Power flow control (“smart“ devices)

- Flow control devices PST, FACTS, HVDC

19. Market Rules

20. Market integration:

- Expansion of markets

- Expansion of control zones



Overview








Mapping of flexibility options

22/05/2014

Short term flexibility Long term flexibility

Lower ST/MT flex potential, unit commitment constraints

Mid term flexibility

SUP

PLY

Coal

Lower ST/MT flex potential, unit commitment constraints

Lignite

Lower ST flex potential, unit commitment constraints

CCGT Flex mode can be enhanced

Flexible – high variable costs OCGT

High variable costs, limited local supply Biogas

Stochastic behaviour – Perceptual and political concerns(waste of ´free´ energy) VRES APC

Flexible –high variable costs, emissions ICE

Nuclear

Constrained due to primary operation Large CHP

Constrained due to primary operation Micro CHP

DEM

AN

D

Industrial DR High potential – flexibility constrained by primary industrial process

Small scale DR High potential – flexibility depends on user behaviour

Electric Vehicles

Heat pumps

Electric heating

STO

RA

GE

Pumped Hydro Low potential for extra expansion

AA-CAES Low efficiency, restricted potential for expansion

Very high investment costs Flywheels

Technology development needed for efficiency improvement Batteries

Low efficiency – option for seasonal storage Power to gas

Constrained by transport sector/primary operation

Constrained by heat sector/primary operation

Constrained by heat sector, low efficiency

Red options are small-scale distributed technologies – communication & control infrastructure key enabler Bold/Underscore options are mature technologies – maturity of most demand and storage options is low



Market barriers


-20000

0

20000

40000

60000

80000

100000

120000

1 5001

Ohne EE

20% EE

40% EE

0

100000

200000

300000

400000

500000

600000

700000

800000

0%

2%

4%

6%

7%

9%

11

%

13

%

15

%

17

%

19

%

20

%

22

%

24

%

26

%

28

%

30

%

32

%

34

%

35

%

37

%

39

%

41

%

43

%

45

%

47

%

48

%

50

%

52

%

54

%

56

%

58

%

60

%

61

%

63

%

65

%

67

%

69

%

71

%

73

%

74

%

76

%

78

%

80

%

82

%

84

%

86

%

87

%

89

%

91

%

93

%

95

%

97

%

99

%

Grundlasttechnologie

Mittellasttechnologie

Spitzenlasttechnologie

Co

sts

[€/k

Wa]

time [h] 8760 0

8760 0

Dem

and

[G

W]

0% VRES 40% VRES

Peak load technology

Middle load technology

Base load technology

20% VRES

Residual load curve shifts

because of additional VRES

time [h]

Base load technology

Middle load technology

Peak load technology

0% VRES

20% VRES

40% VRES

> VRES have low marginal costs

– Downward pressure to electricity prices,

– Reduced full-load hours for conventional units

> Still, conventional peak power plants are needed to

meet load in times of low VRES generation.

> How to incentivize flexibility?

– Supply options are driven by market prices

– Flexibility options are driven by market price

variability (spreads)


Overview








The Flexibility Gap


Low High

Existing Supply Flex New Supply Flex

Fle

xib

ilit

y

VRES

Fle

xib

ility

Ga

p

Storage Flex

Demand Flex


Conclusions and recommendations


> A flexibility gap is created by the shift towards high-VRES

systems

> New flexibility options in demand and storage require control and

communication infrastructure

> VRES control is unavoidable for higher RES shares

> Changing the market is needed for reducing the flexibility gap

> Incentives and systems for demand management are needed

> Extending the market size is a no regret solution

© ECOFYS | | 22/05/2014

Questions?

> Dr. Georgios Papaefthymiou

Ecofys Germany GmbH

Am Karlsbad 11

10785 Berlin

Germany

E: [email protected]

I: www.ecofys.com
