Sustainable use of excess wind power shares

Transcription

1 Christine Krüger Sustainable use of excess wind power shares A multi criteria analysis of different grid- and storage options 7th International Renewable Energy Storage Conference and Exhibition (IRES 2012) November 12-14, 2012, bcc Berliner Congress Center, Berlin/Germany World Council for Renewable Energy (WCRE); EUROSOLAR, The European Association for Renewable Energy

2 SUSTAINABLE USE OF EXCESS WIND POWER SHARES A MULTI CRITERIA ANALYSIS OF DIFFERENT GRID- AND STORAGE OPTIONS Christine Krüger Research Group Future Energy and Mobility Structures

3 Excess wind power shares Grid restrictions or negative residual loads Two possible definitions: 1) Renewable energy that cannot be used due to grid restrictions Local problem Energy must be curtailed 2) Renewable feed-in that exceeds electricity demand Negative residual loads - global problem Here: Focus on situation in November 2012 IRES C. KRÜGER 2

4 Development of surplus energy amounts Rapid increase in curtailed wind energy Grid extension cannot keep up with growth in installed renewable capacities Curtailment Curtailment (GWh) Bottlenecks: distribution grid (110 kv), since 2009: also transmission grid (220/380 kv) Source: J. Bömer (ecofys) Abschätzung der Bedeutung des Einspeisemanagements nach EEG Auswirkungen auf die Windenergieerzeugung in den Jahren 2009 und 2010, Berlin, Oktober November 2012 IRES C. KRÜGER 3

5 What can be done? Alternatives to handle surplus energy amounts Different options: Availability? AC DC Which is Over- the best alternawve? Storage head trans- mission High Grid temp. trans- extension mission Implementa>on >me? lines thermal rawng of transm. lines Under- ground Cables lines Resources? Cost? New techno- logies Ecological Impact? Hydro- gen Acceptance? Com- pressed Air BaZer- ies Pumped Hydro November 2012 IRES C. KRÜGER 4

6 Multi Criteria Analysis One method for assessing such problems The Multi Criteria Analysis (MCA) is a method to face complex problems where one-dimensional approaches fall short In the MCA, the analyst structures the problem, evaluetes the possible solutions and creates a basis for decision-making Results of the MCA: Ranking of alternatives Awareness of influences in decision making Consciousness of priorities 12 November 2012 IRES C. KRÜGER 5

7 Multi Criteria Analysis Procedure WeighWng Four steps: Criteria 1. Determine alternatives suitable for the problem 2. Define criteria which fit the alternatives 3. Evaluate the alternatives against the criteria 4. Weighting of the criteria AlternaWves Weighted sum of scores Result The result is the weighted sum of evaluations 12 November 2012 IRES C. KRÜGER 6

8 Multi Criteria Analysis 1) Determine alternatives suitable for the problem WeighWng Criteria AlternaWves Weighted sum of scores Result 12 November 2012 IRES C. KRÜGER 7

9 Multi Criteria Analysis 1) Determine alternatives suitable for the problem Curtailment Hydrogen (cavern storage) Hydrogen (gas grid) DC overhead lines DC underground cables AC overhead lines AC underground cables Dynamic thermal rawng * High temp. transmission lines Redox- Flow- BaZeries NaS- BaZeries CAES (status) CAES (adiabawc) Pumped hydro (status) Pumped hydro (new concepts) * dt: Freileitungsmonitoring DC: Direct Current AC: AlternaWng Current CAES: Compressed Air Energy Storage NaS: Sodium Sulphur 12 November 2012 IRES C. KRÜGER 8

10 Multi Criteria Analysis 2) Define criteria WeighWng Criteria AlternaWves Weighted sum of scores Result 12 November 2012 IRES C. KRÜGER 9

11 Multi Criteria Analysis 2) Define criteria Criteria must Technology PoliWcs & Society Ecology aim at the relevant characteristics of the alternatives Efficiency be free of redundancies Compliance or overlappings with be precisely defined ImplementaWon Wme poliwcal goals NaWonal Independence Resources GHG Emissions Economy Specific cost Enhancement of compewwon InnovaWon potenwal Employment po- tenwal Other Emissions Export potenwal Market potenwal Social acceptance Interference w. sens. Ecosystems Controllability Effects on the landscape Risk in case of failure Degree of coverage AddiWonal uses 12 November 2012 IRES C. KRÜGER 10

12 Multi Criteria Analysis 3) Evaluate the alternatives against the criteria WeighWng Criteria AlternaWves Weighted sum of scores Result 12 November 2012 IRES C. KRÜGER 11

13 Multi Criteria Analysis 3) Evaluate the alternatives against the criteria Evaluate the alternatives Calculations Inquiries Expert interviews Criteria Fit indicators for each criterion 0 for the weakest, 10 for the strongest alternatives linear values for other alternatives 5 if evaluation is not possible AlternaWves November 2012 IRES C. KRÜGER 12

14 Multi Criteria Analysis 4) Weighting of the criteria WeighWng Criteria AlternaWves Weighted sum of scores Result November 2012 IRES C. KRÜGER 13

15 Multi Criteria Analysis 4) Weighting of the criteria Many different weighting methods. Examples: Equal weights (w 1 = w 2 = = w n = 1/n) Subjective weighting methods Rank-order weighting (w 1 w 2 w n, Σw i = 1) Analytical Hierarchy Process (AHP) Objective weighting methods Here: use the AHP Analytical Good documentation of weighting steps Identify inconsistent weightings 12 November 2012 IRES C. KRÜGER 14

16 Analytical Hierarchy Process (AHP) Procedure 1. Categorise the criteria in two or more levels 2. Pairwise comparison of criteria in each category How much more important is criterion I in comparison to criterion II? Scale: 1/9 (much less important) 1 (equal) 9 (much more important) ResulWng weighwng vector 12 November 2012 IRES C. KRÜGER 15

17 Analytical Hierarchy Process (AHP) Weighting results in this project Efficiency 22% ImplementaWon Wme 5% Specific cost 74% InnovaWon potenwal 12% Enhancement of compewwon Export potenwal 9% 17% 6#&%&8*+ 75-+!"#$%&' (&)*+,,-+ Market potenwal Controllability Degree of coverage 29% 3% 21% AddiWonal uses 8% Resources GHG Emissions Other Emissions Interference w. Ecosystems Risk in case of failure 16% 56% 4% 18% 7% 6#&(&)* &(/0#1+2+ 3&#/"4*+ 5-+ Compliance with poliwcal goals NaWonal independence Employment potenwal Social acceptance Effects on the landscape 4% 17% 52% 20% 8% 12 November 2012 IRES C. KRÜGER 16

18 Applying values and weights Results of the MCA WeighWng Criteria AlternaWves Weighted sum of scores Result November 2012 IRES C. KRÜGER 17

19 Result of the MCA Ranking of technologies for sustainable handling of excess wind power QEG3L<H#2N:;L3B#;3PGF# Q,#4G>:;F;?4G>#H3JB:1# Q,#?I:;N:3>#B<G:1#,-./#03><3J3PH5# -,#?I:;N:3>#B<G:1# D<FN#2:LMO#2;3G1L<11<?G#B<G:1# K4LM:>#NE>;?#0G:C#H?GH:M215#,4;23<BL:G2# K4LM:>#NE>;?# # DE>;?F:G#0F31#F;<>5# -,#4G>:;F;?4G>#H3JB:1# DE>;?F:G#0H3I:;G#12?;3F:5# 63/7839:;<:1#,-./# # $%# $!#!"# '(# '%# ''# '&# '$# '$# &"# &"# &'# &'# &&# &$# )# *)# +)#!)# $)# &)# ')# %)# ()#!"#$%& 12 November 2012 IRES C. KRÜGER 18

20 Further Results Analyses based on the MCA The MCA offers many different analysis options: Why did a technology win the MCA? Why did another score less? e.g. thermal rating vs. curtailment vs. CAES What are the advantages of different technologies in different regards? e.g. ecological vs. economical scores Is one kind of technologies suited better than another? e.g. grid extension vs. storage Are the results robust against changing priorities? 12 November 2012 IRES C. KRÜGER 19

21 Analysis of results Comparison among thermal rating, curtailment and CAES 9:(34&#)5( ;'4#4%"( 9:(34&#)5( ;'4-4/"( Dynamic!"#$%&'()*+,%$-(,$.#/0(12(34&#)5( thermal rawng $#"62.780" >1272+=" 67(34&#)5( 8+'*#4-4/"( :(34&#)5( 34-&.'5(<( =4'&+)"( 28,/0&*$1, $'" 450*0(7, +,-.+/+"012345"'(("62.780"!" $#" )" %" Curtailment!"#$%&'()*$+,-.,/0&*$1,!!" $" &" 23,/0&*$1, '(" 450'067,!!"62.780" 941:72;2<=" '" %" 3<%/012('% #7020=;% CAES (status)!"#$%&'()(*'+,%-.%/012('% 34%/012('% :;% 68 Points $" )" $#" #"!" (" '" $#"62.780" >12;2<=" '" ;.,/0&*$1, 450'067, '*" 59 Points )" $" '" &" 3,/0&*$1, /0'&$51,9, :05&)$7, <%/012('% #7090:;% #"62.780" A21.48=" >%/012('% $0716(;% 39 Points 12 November 2012 IRES C. KRÜGER 20

22 Analysis of results Robustness of ranking Are the results robust against changing priorities? Apply different weightings 12 November 2012 IRES C. KRÜGER 21

23 Conclusions Sustainable use of excess wind energy shares (focus on 2020) The process of the MCA helps to structure and assess the reasons behind decision making and leads to a well documented finding Dynamic thermal rating systems for overhead transmission lines are considered one of the best options to deal with surplus energy DC underground cables, high temperature transmission lines and adiabatic CAES are also well suited Storage options (except adiabatic CAES) score rather low Time horizon 2020 results would be different for longer timescale (shift from spatial to temporal challenges new storage technologies will improve technologically and economically) 12 November 2012 IRES C. KRÜGER 22

24 Thank you for your kind azenwon!